TY - JOUR TI - Sinus Node Sparing Novel Hybrid Approach for Treatment of Inappropriate Sinus Tachycardia/Postural Orthostatic Sinus Tachycardia With New Electrophysiological Finding T2 - American Journal of Cardiology VL - 124 IS - 2 SP - 224 EP - 232 PY - 2019 DO - 10.1016/j.amjcard.2019.04.019 AU - de Asmundis, C. AU - Chierchia, G.-B. AU - Sieira, J. AU - Ströker, E. AU - Umbrain, V. AU - Poelaert, J. AU - Brugada, P. AU - La Meir, M. AD - Heart Rhythm Management Center, Postgraduate Program in Cardiac Electrophysiology and Pacing, Universitair Ziekenhuis Brussel – Vrije Universiteit Brussel, Brussels, Belgium AD - Anesthesiology Department, Universitair Ziekenhuis Brussel – Vrije Universiteit Brussel, Brussels, Belgium AD - Cardiac Surgery Department, Universitair Ziekenhuis Brussel – Vrije Universiteit Brussel, Brussels, Belgium AB - The ideal treatment of Inappropriate Sinus Tachycardia (IST) and Postural Orthostatic Tachycardia Syndrome (POTS) still needs to be defined. Medical treatment yields suboptimal results, endocardial ablation of the sinus node (SN) may risk phrenic nerve damage and open heart surgery may be accompanied by unjustified invasive risks. We describe our first experience of 50 consecutive patients (41 females, 22.83 ± 3.91 years) having undergone a novel hybrid thoracoscopic ablation for drug resistant IST (n = 39, 78%) or POTS (n = 11, 22%). The SN was identified with the help of 3D mapping. Surgery was performed through 3 (5 mm) ports from the right side. A minimally invasive approach with a radio frequency bipolar clamp was utilized to a new target sparing the SN region, to isolate the superior and the inferior caval veins, and a crista terminalis line was made. All lines were interconnected. Normal SR was restored in all patients at the end of the procedure. All patients discontinued medication during the follow-up. After a blanking period of 6 months all patients presented stable SR. At a mean of 28.4 ± 1.2 months, normal SN ruction and chronotropic response to exercise was present. In the 11 patients initially diagnosed with POTS, no syncope occurred. During the follow-up, pericarditis was the most common complication (39 patients; 78%) with complete resolution in all cases. In conclusions the preliminary results of our first experience with a SN sparing novel hybrid ablation of IST/POTS, using surgical thoracoscopic video-assisted epicardial ablation combined with concomitant endocardial 3D mapping may prove an efficient and safe therapeutic option in patients with symptomatic drug resistant IST and POTS. Importantly, in our study all patients had a complete resolution of the symptoms and restored normal SN activity. © 2019 Elsevier Inc. N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065441973&doi=10.1016%2fj.amjcard.2019.04.019&partnerID=40&md5=1b46d71dfbf4cdc3d9a4830149dd350c ER - TY - JOUR TI - Vagal and Sympathetic Function in Neuropathic Postural Tachycardia Syndrome T2 - Hypertension (Dallas, Tex. : 1979) VL - 73 IS - 5 SP - 1087 EP - 1096 PY - 2019 DO - 10.1161/HYPERTENSIONAHA.118.11803 AU - Jacob, G. AU - Diedrich, L. AU - Sato, K. AU - Brychta, R.J. AU - Raj, S.R. AU - Robertson, D. AU - Biaggioni, I. AU - Diedrich, A. AD - From the Department of Medicine F & J. Recanati Autonomic Dysfunction Center, Tel Aviv "Sourasky" Medical Center and Sackler Faculty of Medicine, University of Tel Aviv, Israel AD - US Department of Veterans Affairs, Tennessee Valley Healthcare System, United States AD - Division of Clinical Pharmacology, Department of Medicine, Autonomic Dysfunction Center (K.S., D.R., I.B., Vanderbilt University School of Medicine, Nashville, TN, United States AD - Department of Medicine, Tokyo Women's Medical University, Medical Center East, Japan (K.S.) AD - Diabetes, Endocrinology, Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States AD - Department of Neurology (D.R.), Vanderbilt University School of Medicine, Nashville, TN, United States AD - Department of Biomedical Engineering (A.D.), Vanderbilt University School of Medicine, Nashville, TN, United States AB - The diagnosis of neuropathic postural tachycardia syndrome (POTS) requires research techniques not available clinically. We hypothesized that these patients will have impaired vagal and sympathetic cardiovascular control that can be characterized with clinical autonomic tests. We included 12 POTS patients with possible neuropathic subtype because of normal plasma norepinephrine and no increase in upright blood pressure. We compared them to 10 healthy subjects. We assessed hemodynamics, heart rate and blood pressure variability, baroreflex sensitivity, raw and integrated muscle sympathetic nerve activity, and blood volume. To understand the vagal/sympathetic control, we dissected the phase 2 of Valsalva maneuver (VM) into early (VM2e) and late (VM2l). POTS' upright heart rate increased 43±3 bpm. Patients had normal plasma volume but reduced red blood cell volume (1.29 L versus predicted normal values 1.58 L; P=0.02). Vagal indices of heart rate variability, HFRRI (430±130 versus 1680±900; P=0.04), PNN50, and root mean squared of successive differences were lower in POTS. Patients showed a decrease in vagal baroreflex sensitivity (VM2e; P=0.04). In POTS, integrated muscle sympathetic nerve activity was lower at rest (12±1.5 versus 20±2 burst/min; P=0.004) and raw muscle sympathetic nerve activity spike analysis showed blunted responses during VM2e, despite a greater drop in systolic blood pressure (34±5 in POTS and 14±6 mm Hg in controls; P=0.01). This cohort of POTS patients enriched for possible neuropathic subtype had lower resting muscle sympathetic nerve activity, impaired vagal cardiac control, and exaggerated drop in blood pressure in response to VM and a delay in the sympathetic cardiovascular responsiveness during hypotensive challenge. KW - baroreflex KW - blood pressure KW - heart rate KW - tachycardia KW - Valsalva maneuver N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85064725463&doi=10.1161%2fHYPERTENSIONAHA.118.11803&partnerID=40&md5=d2efdfea1d915c49489b8bda78234ba7 ER - TY - JOUR TI - Frequency Domain Indices of Heart Rate Variability are Useful for Differentiating Vasovagal Syncope and Postural Tachycardia Syndrome in Children T2 - Journal of Pediatrics VL - 207 SP - 59 EP - 63 PY - 2019 DO - 10.1016/j.jpeds.2018.11.054 AU - Wang, Y. AU - Zhang, C. AU - Chen, S. AU - Li, X. AU - Jin, H. AU - Du, J. AD - Department of Pediatrics, Peking University First Hospital, Beijing, China AD - Division of Biological Sciences, University of California, San Diego, La Jolla, CA, United States AD - Department of Medical Statistics, Peking University First Hospital, Beijing, China AD - Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China AB - Objective: To explore the value of frequency domain indices of heart rate variability (HRV) in the differential diagnosis between pediatric vasovagal syncope and postural tachycardia syndrome (POTS). Study design: Eighty-five patients aged 7-16 years with either vasovagal syncope or POTS were enrolled in the experimental group; 18 healthy children served as controls. Holter electrocardiography was used to detect HRV frequency-domain indices in patients with vasovagal syncope, patients with POTS, and control subjects. The differences in HRV indices were compared between the vasovagal syncope and POTS groups. The receiver operating characteristic (ROC) curve was calculated to analyze the predictive value of HRV for the differential diagnosis between vasovagal syncope and POTS in children. In addition, 37 children aged 7-17 years with either vasovagal syncope or POTS were recruited as an external validation group. Results: The daytime ultra-low frequency (dULF), nighttime ULF (nULF), daytime very low frequency (dVLF), and nighttime VLF (nVLF) were higher in the vasovagal syncope group compared with the POTS group (P <.01 for dULF, dVLF, and nVLF; P <.05 for nULF). The dULF, nULF, dVLF, and nVLF yielded a sensitivity of 73.3%, 71.1%, 68.9%, and 62.2%, respectively, and a specificity of 72.5%, 62.5%, 60.0%, and 60.0%, respectively, to differentiate vasovagal syncope from POTS. The external validation with clinical diagnostic standard showed that a dULF cutoff value of 36.2 ms 2 for differentiating POTS from vasovagal syncope yielded a sensitivity of 71.4%, a specificity of 75.0%, and an accuracy of 73.0%. Conclusion: dULF may be a useful measure for the differential diagnosis between vasovagal syncope and POTS in adolescents. © 2018 Elsevier Inc. KW - children KW - heart rate variability KW - postural tachycardia syndrome KW - vasovagal syncope N1 - Cited By :1 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85059542778&doi=10.1016%2fj.jpeds.2018.11.054&partnerID=40&md5=3131ce31619a2042bdbbcc898cf9ffe3 ER - TY - JOUR TI - Self-paced team-sport match simulation results in reductions in voluntary activation and modifications to biological, perceptual, and performance measures at halftime and for up to 96 hours postmatch T2 - Journal of Strength and Conditioning Research VL - 32 IS - 12 SP - 3552 EP - 3563 PY - 2018 AU - Tofari, P.J. AU - Kemp, J.G. AU - Cormack, S.J. AD - School of Exercise Science, Australian Catholic University, Melbourne, Australia AB - Assessing responses to soccer match play is limited by match variability or unrealistic simulations. To address this, the biological, perceptual, and performance responses were assessed using a self-paced, simulated soccer match protocol using a nonmotorized treadmill. Twelve male team-sport athletes performed the 90-minute simulation. Match activity, quadriceps twitch interpolation (voluntary activation [%VA] and potentiated twitch [POT]), biochemical markers, strength and power performance, rating of perceived exertion (RPE), and self-report wellness were collected prematch, halftime, postmatch, and 2, 24, 48, 72, and 96-hour postmatch. Change compared with prematch was calculated using effect size ±90% confidence limit, and relationships were assessed using regression analysis. Subjects covered 12,445.8 ± 768.7 m at 87.1 ± 3.2% maximal heart rate (mean ± SD). Reductions in %VA and POT was present at halftime (20.38 ± 0.46 and 20.79 ± 0.30, respectively) and persisted postmatch. Squat jump height decreased at halftime (20.42 ± 0.31) and was decreased until Post96. Perceptual fatigue, soreness (-0.92 ± 0.88 and -1.49 ± 0.76, respectively), and creatine kinase (CK) (1.11 ± 0.43) peaked at Post24. Pretest strength (N·kg-1) correlated with changes in CK (r = 20.58 to 20.81), peak oxygen consumption (Vo2peak) correlated with reduced perceived wellness at Post24 (r = 0.44–0.58) and RPE post (r = 20.71 ± 0.28). High-speed running correlated with soreness (r2 = 0.42) and very high-speed running with reduced POT (r2 = 0.61). Previously, unreported half-time reductions in %VA and POT plateaued by postmatch, suggesting a role in regulating second-half performance. Perceptual and neuromuscular responses seem related to running intensity. Greater lower-body strength and Vo2peak were associated with less CK (i.e., muscle damage) and perceptual responses postmatch, respectively, suggesting a training focus should be placed on these capacities. © 2017 National Strength and Conditioning Association. KW - Activity profile KW - Central fatigue KW - Nonmotorized treadmill KW - Peripheral fatigue KW - Physical characteristics N1 - Cited By :3 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85034109145&partnerID=40&md5=0808eabae54816e8022c219a16682087 ER - TY - JOUR TI - Migraine and Autonomic Dysfunction: Which Is the Horse and Which Is the Jockey? T2 - Current Pain and Headache Reports VL - 22 IS - 3 PY - 2018 DO - 10.1007/s11916-018-0671-y AU - Miglis, M.G. AD - Department of Neurology, Division of Autonomic Disorders, Stanford University, 213 Quarry Road, M/C 5992, Palo Alto, CA 94304, United States AB - Purpose of Review: Symptoms of autonomic dysfunction are common in patients with migraine, both during and between migraine attacks. Studies evaluating objective autonomic testing in patients have found significant, though somewhat conflicting results. The purposes of this review are to summarize and interpret the key findings of these studies, including those evaluating heart rate variability, autonomic reflex testing, and functional imaging in patients with migraine. The neuroanatomy of the central autonomic network as it relates to migraine is also reviewed. Recent Findings: Several studies have evaluated autonomic balance in migraineurs, with conflicting results on the magnitude of sympathetic versus parasympathetic dysfunction. Most studies demonstrate sympathetic impairment, with a lesser degree of parasympathetic impairment. Summary: Three trends have emerged: (1) migraine with aura tends to produce more significant autonomic dysfunction than migraine without aura, (2) sympathetic impairment is more common than parasympathetic impairment, and (3) sympathetic impairment is common in the interictal period, with increased sympathetic responsiveness during the ictal period, suggesting adrenoreceptor hypersensitivity. © 2018, Springer Science+Business Media, LLC, part of Springer Nature. KW - Autonomic KW - HRV KW - Migraine KW - Parasympathetic KW - POTS dysautonomia KW - Sympathetic KW - Syncope KW - Tilt table KW - Valsalva N1 - Cited By :5 N1 - Export Date: 11 October 2019 M3 - Review DB - Scopus C7 - 19 UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042547958&doi=10.1007%2fs11916-018-0671-y&partnerID=40&md5=2689d9214bd6cf1e94b98c27cdaaf8a2 ER - TY - JOUR TI - Investigating the relationship between cardiac interoception and autonomic cardiac control using a predictive coding framework T2 - Autonomic Neuroscience: Basic and Clinical VL - 210 SP - 65 EP - 71 PY - 2018 DO - 10.1016/j.autneu.2018.01.001 AU - Owens, A.P. AU - Friston, K.J. AU - Low, D.A. AU - Mathias, C.J. AU - Critchley, H.D. AD - Lab of Action & Body, Department of Psychology, Royal Holloway, University of London, Egham, Surrey, United Kingdom AD - Institute of Neurology, University College London, London, WC1N 3BG, United Kingdom AD - National Hospital Neurology and Neurosurgery, UCL NHS Trust, London, WC1N 3BG, United Kingdom AD - Wellcome Trust Centre for Neuroimaging, University College LondonWC1N 3BG, United Kingdom AD - School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 2AB, United Kingdom AD - Hospital of St John & St Elizabeth, London, NW8 9NH, United Kingdom AD - Psychiatry, Brighton and Sussex Medical School, Brighton, BN1 9RR, United Kingdom AD - Sussex Partnership NHS Foundation Trust, Brighton, BN1 9RRUK, United Kingdom AD - Sackler Centre for Consciousness Science, University of SussexBN1 9RR, United Kingdom AB - Predictive coding models, such as the ‘free-energy principle’ (FEP), have recently been discussed in relation to how interoceptive (afferent visceral feedback) signals update predictions about the state of the body, thereby driving autonomic mediation of homeostasis. This study appealed to ‘interoceptive inference’, under the FEP, to seek new insights into autonomic (dys)function and brain–body integration by examining the relationship between cardiac interoception and autonomic cardiac control in healthy controls and patients with forms of orthostatic intolerance (OI); to (i) seek empirical support for interoceptive inference and (ii) delineate if this relationship was sensitive to increased interoceptive prediction error in OI patients during head-up tilt (HUT)/symptom provocation. Measures of interoception and heart rate variability (HRV) were recorded whilst supine and during HUT in healthy controls (N = 20), postural tachycardia syndrome (PoTS, N = 20) and vasovagal syncope (VVS, N = 20) patients. Compared to controls, interoceptive accuracy was reduced in both OI groups. Healthy controls' interoceptive sensibility positively correlated with HRV whilst supine. Conversely, both OI groups' interoceptive awareness negatively correlated with HRV during HUT. Our pilot study offers initial support for interoceptive inference and suggests OI cohorts share a central pathophysiology underlying interoceptive deficits expressed across distinct cardiovascular autonomic pathophysiology. From a predictive coding perspective, OI patients' data indicates a failure to attenuate/modulate ascending interoceptive prediction errors, reinforced by the concomitant failure to engage autonomic reflexes during HUT. Our findings offer a potential framework for conceptualising how the human nervous system maintains homeostasis and how both central and autonomic processes are ultimately implicated in dysautonomia. © 2018 Elsevier B.V. KW - Active inference KW - Autonomic nervous system KW - Dysautonomia KW - Free-energy principle KW - Heart rate variability KW - Homeostasis KW - Interoception KW - Interoceptive (active) inference KW - Predictive coding N1 - Cited By :7 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85040237877&doi=10.1016%2fj.autneu.2018.01.001&partnerID=40&md5=ec84f839cf9a837c0a7b80bccee3903d ER - TY - JOUR TI - Postural orthostatic tachycardia in a patient with type 2 diabetes with diabetic neuropathy T2 - International Heart Journal VL - 59 IS - 6 SP - 1488 EP - 1490 PY - 2018 DO - 10.1536/ihj.17-628 AU - Tomichi, Y. AU - Kawano, H. AU - Mukaino, A. AU - Chiba, A. AU - Doi, Y. AU - Arakawa, S. AU - Ishimatsu, T. AU - Fukae, S. AU - Abiru, N. AU - Maemura, K. AD - Department of Cardiovascular Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan AD - Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan AD - Department of Endocrinology and Metabolism, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan AB - A 24-year-old Japanese man with type 2 diabetes mellitus and diabetic neuropathy was admitted to our ward to evaluate the cause of orthostatic intolerance. During a head-up tilt test, his heart rate increased from 105 to 155 beats/minute within 3 minutes, and chest discomfort began. He was diagnosed with postural orthostatic tachycardia syndrome (POTS), and orthostatic intolerance disappeared after β-blocker treatment. Scintigraphy using123I-metaiodobenzylguanidine showed decreased cardiac uptake. Power spectral analysis of heart rate variability for 24 hours in Holter electrocardiography demonstrated decreases in both sympathetic and parasympathetic nervous system activities, with a greater decrease in parasympathetic activity than sympathetic activity. The relative sympathetic hyperactivity in the present patient with diabetic neuropathy seemed to be related to POTS. © 2018, International Heart Journal Association. All rights reserved. KW - Autonomic nervous system KW - Head-up tilt test KW - Holter electrocardiography KW - Orthostatic intolerance N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85057418816&doi=10.1536%2fihj.17-628&partnerID=40&md5=fc1f963eb5cd0b8c18d3e11f15fb3753 ER - TY - JOUR TI - Improved Patient Outcomes by Normalizing Sympathovagal Balance: Differentiating Syncope - Precise Subtype Differentiation Leads to Improved Outcomes T2 - Cardiology Research and Practice VL - 2018 PY - 2018 DO - 10.1155/2018/9532141 AU - Depace, N.L. AU - Bateman, J.A. AU - Yayac, M. AU - Oh, J. AU - Siddique, M. AU - Acosta, C. AU - Pinales, J.M. AU - Vinik, A.I. AU - Bloom, H.L. AD - Department of Clinical Medicine, Hahnemann Hospital, Drexel University College of Medicine, 438 Ganttown Rd., Ste. B8-B9, Sewell, NJ 08080, United States AD - Department of Medicine Pathology and Neurobiology, Research and Neuroendocrine Unit, Strelitz Diabetes Center, Eastern Virginia Medical School, 855 W. Brambleton Ave., Norfolk, VA 23510, United States AD - Department of Cardiac Electrophysiology and Medicine, Atlanta VAMC, Emory University, School of Medicine, 1670 Clairmont Rd., Decatur, GA 30033, United States AB - Syncope is difficult to definitively diagnose, even with tilt-table testing and beat-to-beat blood pressure measurements, the gold-standard. Both are qualitative, subjective assessments. There are subtypes of syncope associated with autonomic conditions for which tilt-table testing is not useful. Heart rate variability analyses also include too much ambiguity. Three subtypes of syncope are differentiated: vasovagal syncope (VVS) due to parasympathetic excess (VVS-PE), VVS with abnormal heart rate response (VVS-HR), and VVS without PE (VVS-PN). P&S monitoring (ANSAR, Inc., Philadelphia, PA) differentiates subtypes in 2727 cardiology patients (50.5% female; average age: 57 years; age range: 12-100 years), serially tested over four years (3.3 tests per patient, average). P&S monitoring noninvasively, independently, and simultaneously measures parasympathetic and sympathetic (P&S) activity, including the normal P-decrease followed by an S-increase with head-up postural change (standing). Syncope, as an S-excess (SE) with stand, is differentiated from orthostatic dysfunction (e.g., POTS) as S-withdrawal with stand. Upon standing, VVS-PE is further differentiated as SE with PE, VVS-HR as SE with abnormal HR, and VVS-PN as SE with normal P- and HR-responses. Improved understanding of the underlying pathophysiology by more accurate subtyping leads to more precise therapy and improved outcomes. © 2018 Nicholas L. DePace et al. N1 - Cited By :1 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus C7 - 9532141 UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047874579&doi=10.1155%2f2018%2f9532141&partnerID=40&md5=c93bdaeadf34b60317cb6c00030896ee ER - TY - JOUR TI - Postural tachycardia in hypermobile Ehlers-Danlos syndrome: A distinct subtype? T2 - Autonomic Neuroscience: Basic and Clinical VL - 208 SP - 146 EP - 149 PY - 2017 DO - 10.1016/j.autneu.2017.10.001 AU - Miglis, M.G. AU - Schultz, B. AU - Muppidi, S. AD - Department of Neurology, Stanford University Medical Center, 213 Quarry Road, M/C 5992, Palo Alto, CA 94304, United States AD - Department of Psychiatry, Stanford University Medical Center, 450 Broadway, Redwood City, CA 94305, United States AB - Introduction It is not clear if patients with postural tachycardia syndrome (POTS) and Ehlers-Danlos syndrome (hEDS) differ from patients with POTS due to other etiologies. We compared the results of autonomic testing and healthcare utilization in POTS patients with and without hEDS. Methods Patients with POTS + hEDS (n = 20) and POTS controls without hypermobility (n = 20) were included in the study. All patients underwent autonomic testing, and the electronic medical records were reviewed to determine the number and types of medications patients were taking, as well as the number of outpatient, emergency department, and inpatient visits over the prior year. Results Patients with hEDS had twice as many outpatient visits (21 v. 10, p = 0.012), were taking more prescription medications (8 vs. 5.5, p = 0.030), and were more likely to see a pain physician (70% vs 25%, p = 0.005). Autonomic testing demonstrated a slight reduction in heart rate variability and slightly lower blood pressures on tilt table testing in hEDS patients, however for most patients these variables remained within the range of normal. Orthostatic tachycardia on tilt table testing was greater in POTS controls (46 bpm vs 39 bpm, p = 0.018). Abnormal QSweat responses were common in both groups (38% of POTS + hEDS and 36% of POTS controls). Conclusions While autonomic testing results were not significantly different between groups, patients with POTS + hEDS took more medications and had greater markers of healthcare utilization, with chronic pain likely playing a prominent role. © 2017 Elsevier B.V. N1 - Cited By :2 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85030481905&doi=10.1016%2fj.autneu.2017.10.001&partnerID=40&md5=006e7764dc5722e7a7ae01431c42f315 ER - TY - JOUR TI - Etiology and recovery of neuromuscular fatigue following competitive soccer match-play T2 - Frontiers in Physiology VL - 8 IS - OCT PY - 2017 DO - 10.3389/fphys.2017.00831 AU - Brownstein, C.G. AU - Dent, J.P. AU - Parker, P. AU - Hicks, K.M. AU - Howatson, G. AU - Goodall, S. AU - Thomas, K. AD - Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, United Kingdom AD - Water Research Group, School of Environmental Sciences and Development, Northwest University, Potchefstroom, South Africa AB - Previous research into the etiology of neuromuscular fatigue following competitive soccer match-play has primarily focused on peripheral perturbations, with limited research assessing central nervous system function in the days post-match. The aim of the present study was to examine the contribution and time-course of recovery of central and peripheral factors toward neuromuscular fatigue following competitive soccer match-play. Methods: Sixteen male semi-professional soccer players completed a 90-min soccer match. Pre-, post- and at 24, 48, and 72 h participants completed a battery of neuromuscular, physical, and perceptual tests. Maximal voluntary contraction force (MVC) and twitch responses to electrical (femoral nerve) and transcranial magnetic stimulation (TMS) of the motor cortex during isometric knee-extension and at rest were measured to assess central nervous system (voluntary activation, VA) and muscle contractile (potentiated twitch force, Qtw, pot) function. Electromyography responses of the rectus femoris to single- and paired-pulse TMS were used to assess corticospinal excitability and short-interval intracortical inhibition (SICI), respectively. Fatigue and perceptions of muscle soreness were assessed via visual analog scales, and physical function was assessed through measures of jump (countermovement jump height and reactive strength index) and sprint performance. Results: Competitive match-play elicited significant post-match declines in MVC force (-14%, P < 0.001) that persisted for 48 h (-4%, P = 0.01), before recovering by 72 h post-exercise. VA (motor point stimulation) was reduced immediately post-match (-8%, P < 0.001), and remained depressed at 24 h (-5%, P = 0.01) before recovering by 48 h post-exercise. Qtw,pot was reduced post-match (-14%, P < 0.001), remained depressed at 24 h (-6%, P = 0.01), before recovering by 48 h post-exercise. No changes were evident in corticospinal excitability or SICI. Jump performance took 48 h to recover, while perceptions of fatigue persisted at 72 h. Conclusion: Competitive soccer match-play elicits substantial impairments in central nervous system and muscle function, requiring up to 48 h to resolve. The results of the study could have important implications for fixture scheduling, the optimal management of the training process, squad rotation during congested competitive schedules, and the implementation of appropriate recovery interventions. © 2017 Brownstein, Dent, Parker, Hicks, Howatson, Goodall and Thomas. KW - Central KW - Fatigue KW - Peripheral KW - Recovery KW - Soccer KW - Transcranial magnetic stimulation N1 - Cited By :15 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus C7 - 831 UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85032212475&doi=10.3389%2ffphys.2017.00831&partnerID=40&md5=f530932b2131e02e6269b6d43e3932dd ER - TY - JOUR TI - Comparison of Physiological and Psychological Relaxation Using Measurements of Heart Rate Variability, Prefrontal Cortex Activity, and Subjective Indexes after Completing Tasks with and without Foliage Plants T2 - International journal of environmental research and public health VL - 14 IS - 9 PY - 2017 DO - 10.3390/ijerph14091087 AU - Park, S.-A. AU - Song, C. AU - Oh, Y.-A. AU - Miyazaki, Y. AU - Son, K.-C. AD - Department of Horticultural Therapy, Graduate School of Agricultural and Animal Science, Konkuk University, Seoul, 05029, South Korea AD - Department of Horticultural Therapy, Graduate School of Agricultural and Animal Science, Konkuk University, Seoul, 05029, South Korea AD - Department of Horticultural Therapy, Graduate School of Agricultural and Animal Science, Konkuk University, Seoul, 05029, South Korea AB - The objective of this study was to compare physiological and psychological relaxation by assessing heart rate variability (HRV), prefrontal cortex activity, and subjective indexes while subjects performed a task with and without foliage plants. In a crossover experimental design, 24 university students performed a task transferring pots with and without a foliage plant for 3 min. HRV and oxyhemoglobin (oxy-Hb) concentration in the prefrontal cortex were continuously measured. Immediately thereafter, subjective evaluation of emotions was performed using a modified semantic differential (SD) method and a profile of mood state questionnaire (POMS). Results showed that the natural logarithmic (ln) ratio of low frequency/high frequency, as an estimate of sympathetic nerve activity, was significantly lower while performing the task with foliage plants for the average 3 min measurement interval. Oxy-Hb concentration in the left prefrontal cortex showed a tendency to decrease in the 2-3 min interval in the task with foliage plants compared to the task without plants. Moreover, significant psychological relaxation according to POMS score and SD was demonstrated when the task involved foliage plants. In conclusion, the task involving foliage plants led to more physiological and psychological relaxation compared with the task without foliage plants. KW - brain activity KW - horticultural therapy KW - modified semantic differential method KW - mood state questionnaire KW - near-infrared spectroscopy KW - socio-horticulture N1 - Cited By :9 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85036514257&doi=10.3390%2fijerph14091087&partnerID=40&md5=14a298465cb711226ec08283efa7b715 ER - TY - CONF TI - Toward evaluation of mixed culture's team works: Case study of ship bridge simulator-based training for cadets T2 - IFSA-SCIS 2017 - Joint 17th World Congress of International Fuzzy Systems Association and 9th International Conference on Soft Computing and Intelligent Systems PY - 2017 DO - 10.1109/IFSA-SCIS.2017.8023343 AU - Murai, K. AU - Wang, J. AU - Wang, Y. AU - Qilei, Y. AD - Graduate School of Maritime Sciences, Kobe University, Kobe, Japan AD - Science Division, Zhejiang International Maritime College, Zhoushan, China AB - The seafarer of ocean-going vessel works together with multiple nationalities. There is individual culture and custom for each, and the difference among them is perhaps mental stress. The mental stress and the difference of custom is sometime a reason for human errors. In this paper, we challenge to evaluate the mixed culture's team works for ship bridge teammates for cadets. The index is physiological index which evaluates the mental workload. If we are able to evaluate the stress comes from the mixed culture using the physiological index, we can consider the optimum mixed pot, and prevent human errors by miss much people. We show the results of mental workload among mixed culture. © 2017 IEEE. KW - heart rate variability KW - international team work KW - Japan and China KW - mental workload KW - navigation N1 - Export Date: 11 October 2019 M3 - Conference Paper DB - Scopus C7 - 8023343 UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85030840415&doi=10.1109%2fIFSA-SCIS.2017.8023343&partnerID=40&md5=629f80e3058a891f48c6f1a721466769 ER - TY - JOUR TI - Variability of postural orthostatic tachycardia in patients with myalgic encephalomyelitis and orthostatic intolerance T2 - Heart and Vessels VL - 31 IS - 9 SP - 1522 EP - 1528 PY - 2016 DO - 10.1007/s00380-015-0744-3 AU - Miwa, K. AD - Department of Internal Medicine, Miwa Naika Clinic, 1-4-3 Shintomicho, Toyama, 930-0002, Japan AB - Central nervous system dysfunction with myalgic encephalomyelitis (ME) has been suggested as the main cause of chronic fatigue syndrome. Fluctuation of the symptom severity and hierarchy is a characteristic feature in ME patients. The characteristics of the sympathetic activation may differ between the “good days” and “bad days” in them. Twenty-four ME patients with orthostatic intolerance underwent a conventional 10-min active standing test and echocardiography both on a “good day” and a “bad day”, defined according to the severity of their symptoms. The mean heart rate at rest was significantly higher on the “bad days” than on the “good days”. During the standing test on a “bad day”, 5 patients (21 %) failed to maintain an upright posture for 10 min, whereas on a “good day” all the 24 patients maintained it. Postural orthostatic tachycardia (POT) (increase in heart rate ≥30 beats/min) or severe POT (heart rate ≥120 beats/min) was observed on the “bad days” in 10 patients (43 %) who did not suffer from the severe tachycardia on the “good days”, suggesting the exaggerated sympathetic nervous activation. In contrast, POT did not occur or severe POT was attenuated on the “bad days” in 5 patients (21 %) who developed POT or severe POT on the “good days”, suggesting the impaired sympathetic activation. Echocardiography revealed significantly lower mean values of both the left ventricular end-diastolic diameter and stroke volume index on the “bad days” compared with the “good days”. In conclusion, in ME patients with orthostatic intolerance, the exaggerated activation of the sympathetic nervous system while standing appears to switch to the impaired sympathetic activation after the system is loaded with the additional accentuated stimuli associated with the preload reduction. © 2015, Springer Japan. KW - Chronic fatigue syndrome KW - Myalgic encephalomyelitis KW - Orthostatic intolerance KW - Postural orthostatic tachycardia KW - Sympathetic nervous system N1 - Cited By :6 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84941711497&doi=10.1007%2fs00380-015-0744-3&partnerID=40&md5=05a2f47efac6d8b253387189a0dc64d8 ER - TY - JOUR TI - Postural orthostatic tachycardia syndrome (POTS) as presenting symptom of CIDP T2 - Neurological Sciences VL - 37 IS - 7 SP - 1163 EP - 1166 PY - 2016 DO - 10.1007/s10072-016-2507-z AU - Adamec, I. AU - Bilić, E. AU - Lovrić, M. AU - Habek, M. AD - Referral Centre for Autonomic Nervous System Disorders, Department of Neurology, University Hospital Centre Zagreb, Zagreb, Croatia AD - Referral Center for Neuromuscular Diseases and Clinical Electromyoneurography, Department of Neurology, University Hospital Centre Zagreb, Zagreb, Croatia AD - School of Medicine, University of Zagreb, Zagreb, Croatia AD - Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia KW - Chronic inflammatory demyelinating polyneuropathy KW - Postural orthostatic tachycardia syndrome N1 - Cited By :3 N1 - Export Date: 11 October 2019 M3 - Letter DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84958049844&doi=10.1007%2fs10072-016-2507-z&partnerID=40&md5=8da0a34d34be031ad7c54cf1f1d92e17 ER - TY - JOUR TI - Use of an allostatic neurotechnology by adolescents with postural orthostatic tachycardia syndrome (POTS) is associated with improvements in heart rate variability and changes in temporal lobe electrical activity T2 - Experimental Brain Research VL - 234 IS - 3 SP - 791 EP - 798 PY - 2016 DO - 10.1007/s00221-015-4499-y AU - Fortunato, J.E. AU - Tegeler, C.L. AU - Gerdes, L. AU - Lee, S.W. AU - Pajewski, N.M. AU - Franco, M.E. AU - Cook, J.F. AU - Shaltout, H.A. AU - Tegeler, C.H. AD - Virginia Commonwealth University, Richmond, VA, United States AD - Hypertension and Vascular Research Center, Wake Forest School of Medicine, Winston-Salem, NC, United States AD - Department of Neurology, Wake Forest School of Medicine, Winston-Salem, NC, United States AD - Brain State Technologies LLC, Scottsdale, AZ 85260, United States AD - Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC, United States AD - Departments of Obstetrics and Gynecology and General Surgery, Wake Forest School of Medicine, Winston-Salem, NC, United States AB - Autonomic dysregulation and heterogeneous symptoms characterize postural orthostatic tachycardia syndrome (POTS). This study evaluated the effect of high-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®), a noninvasive, allostatic neurotechnology for relaxation and auto-calibration of neural oscillations, on heart rate variability, brain asymmetry, and autonomic symptoms, in adolescents with POTS. Seven subjects with POTS (three males, ages 15–18) underwent a median of 14 (10–16) HIRREM sessions over 13 (8–17) days. Autonomic function was assessed from 10-min continuous heart rate and blood pressure recordings, pre- and post-HIRREM. One-minute epochs of temporal high-frequency (23–36 Hz) brain electrical activity data (T3 and T4, eyes closed) were analyzed from baseline HIRREM assessment and subsequent sessions. Subjects rated autonomic symptoms before and after HIRREM. Four of seven were on fludrocortisone, which was stopped before or during their sessions. Heart rate variability in the time domain (standard deviation of the beat-to-beat interval) increased post-HIRREM (mean increase 51 %, range 10–143, p = 0.03), as did baroreflex sensitivity (mean increase in high-frequency alpha 65 %, range −6 to 180, p = 0.05). Baseline temporal electrical asymmetry negatively correlated with change in asymmetry from assessment to the final HIRREM session (p = 0.01). Summed high-frequency amplitudes at left and right temporal lobes decreased a median of 3.8 μV (p = 0.02). There was a trend for improvements in self-reported symptoms related to the autonomic nervous system. Use of HIRREM was associated with reduced sympathetic bias in autonomic cardiovascular regulation, greater symmetry and reduced amplitudes in temporal lobe high-frequency electrical activity, and a trend for reduced autonomic symptoms. Data suggest the potential for allostatic neurotechnology to facilitate increased flexibility in autonomic cardiovascular regulation, possibly through more balanced activity at regions of the neocortex responsible for autonomic management. Clinical trial registry “Tilt Table with Suspected postural orthostatic tachycardia syndrome (POTS) Subjects,” Protocol Record: WFUBAHA01. © 2015, The Author(s). KW - Allostasis KW - Autonomic dysregulation KW - Hemispheric asymmetry KW - Nausea KW - Neurotechnology KW - POTS N1 - Cited By :5 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84958053992&doi=10.1007%2fs00221-015-4499-y&partnerID=40&md5=3e0978dd275c7a20e99e3e321b9e598e ER - TY - JOUR TI - The complexity of diagnosing postural orthostatic tachycardia syndrome: Influence of the diurnal variability T2 - Journal of the American Society of Hypertension VL - 10 IS - 3 SP - 263 EP - 270 PY - 2016 DO - 10.1016/j.jash.2016.01.011 AU - Moon, J. AU - Lee, H.S. AU - Byun, J.-I. AU - Sunwoo, J.-S. AU - Shin, J.-W. AU - Lim, J.-A. AU - Kim, T.-J. AU - Shin, Y.-W. AU - Lee, K.-J. AU - Jeon, D. AU - Jung, K.-H. AU - Lee, S.-T. AU - Jung, K.-Y. AU - Chu, K. AU - Lee, S.K. AD - Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 110-744, South Korea AD - Program in Neuroscience, Neuroscience Research Institute, Seoul National University Medical Research Council, Seoul National University College of Medicine, Seoul, South Korea AD - Department of Neurology, EwhaWomans University School of Medicine, Ewha Medical Research Institute, Seoul, South Korea AD - Department of Neurology, CHA Bundang Medical Center, CHA University, Seoungnam, South Korea AB - We investigated how the diagnosis of postural orthostatic tachycardia syndrome (POTS) would be changed due to diurnal variability in orthostatic tachycardia. The orthostatic vital sign test was administered to each patient twice, in the afternoon of the day of admission and the next morning (n = 113). Forty-six patients were diagnosed with POTS, and the remaining 67 patients were assigned to non-POTS group. Heart rate increments after standing were larger in the morning than in the afternoon in every group (all P <.001). Among the POTS patients, 82.6% fulfilled the diagnostic criteria for POTS in the morning and 52.2% in the afternoon. Most POTS group (65.2%) displayed normal result on single orthostatic vital sign test. Orthostatic intolerance symptoms were provoked in only 45.7% of the POTS patients, more frequently in the morning. In conclusion, diurnal variability in hemodynamic parameters and provoked symptoms significantly challenged the diagnosis of POTS. © 2016 American Society of Hypertension. All rights reserved. KW - diurnal variability KW - orthostatic hypotension KW - orthostatic intolerance KW - orthostatic tachycardia KW - Postural tachycardia syndrome N1 - Cited By :5 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84960211845&doi=10.1016%2fj.jash.2016.01.011&partnerID=40&md5=c5253af42019e2f6f7ee5f5e45a46c99 ER - TY - JOUR TI - Hemodynamic profile and heart rate variability in hyperadrenergic versus non-hyperadrenergic postural orthostatic tachycardia syndrome T2 - Clinical Neurophysiology VL - 127 IS - 2 SP - 1639 EP - 1644 PY - 2016 DO - 10.1016/j.clinph.2015.08.015 AU - Crnošija, L. AU - Krbot Skorić, M. AU - Adamec, I. AU - Lovrić, M. AU - Junaković, A. AU - Mišmaš, A. AU - Miletić, V. AU - Šprljan Alfirev, R. AU - Pavelić, A. AU - Habek, M. AD - School of Medicine, University of Zagreb, Zagreb, Croatia AD - University Hospital Center Zagreb, Department of Neurology, Referral Center for Autonomic Nervous System Disorders, Zagreb, Croatia AD - University Hospital Centre Zagreb, Department of Laboratory Diagnostics, Zagreb, Croatia AB - Objectives: To investigate differences in hemodynamic profile between hyperadrenergic and non-hyperadrenergic postural orthostatic tachycardia syndrome (POTS) in response to head-up tilt test (HUTT). Methods: Ten patients with hyperadrenergic and 33 patients with non-hyperadrenergic POTS underwent HUTT consisting of a 10-min supine phase and 30-min 70° tilted phase. Heart rate (HR), systolic and diastolic blood pressure (dBP), and heart rate variability (HRV) parameters of the two groups were compared. Results: Hyperadrenergic patients had higher supine HR (82.6 ± 16.3 bpm vs. 73.8 ± 10.4 bpm, p = 0.048). Supine HRV analysis showed significantly lower cardiac vagal activity and possible predominance of cardiac sympathetic activity in the hyperadrenergic group. Non-hyperadrenergic patients had lower dBP during the first four minutes of tilt. Furthermore, 60% of non-hyperadrenergic patients had lower average dBP in the 1st minute of tilted phase when compared to supine values, whereas only 2 of 10 hyperadrenergic patients exhibited the same response. Syncope or intolerable symptoms, causing early ending of HUTT, developed earlier in the non-hyperadrenergic group (8.9 ± 6.8 min vs. 21.2 ± 3.5 min, p = 0.001). Conclusion: Hyperadrenergic and non-hyperadrenergic type of POTS seem to have distinctly different response to HUTT. Significance: This study has shown significant differences in hemodynamic response to HUTT between hyperadrenergic and non-hyperadrenergic type of POTS indicating possible differences in their pathophysiology. © 2015 International Federation of Clinical Neurophysiology. KW - Head-up tilt test KW - Heart rate variability KW - Hyperadrenergic KW - Non-hyperadrenergic KW - Postural orthostatic tachycardia syndrome N1 - Cited By :3 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84957955995&doi=10.1016%2fj.clinph.2015.08.015&partnerID=40&md5=3cd171baad14a56205e31bcf4612fa72 ER - TY - JOUR TI - Time-dependent heart rate variability in the head-up tilt test in children with postural orthostatic tachycardia syndrome T2 - Chinese Journal of Contemporary Pediatrics VL - 17 IS - 10 SP - 1070 EP - 1073 PY - 2015 DO - 10.7499/j.issn.1008-8830.2015.10.010 AU - Ran, J. AU - Wang, C. AU - Zou, R.-M. AU - Wu, L.-J. AU - Lin, P. AU - Li, F. AU - Xu, Y. AD - Department of Pediatric Cardiovasology, Children's Medical Center, Second Xiangya Hospital of Central South University, Institute of Pediatrics of Central South University, Changsha, 410011, China AB - Objective: To study the time-dependent heart rate (HR) variability in the head-up tilt test (HUTT) in children with postural orthostatic tachycardia syndrome (POTS) and to explore the HR diagnostic criteria for POTS in children. Methods: A retrospective analysis was performed on the clinical data of 105 children diagnosed with POTS with HR ≥120 beats per minute (bpm) within the first 10 minutes of HUTT between January 2007 and December 2014. Their HR variability within the first 10 minutes of HUTT was analyzed. Results: The HR of children with POTS increased gradually from the supine position to a 60° head-up tilt position, and the increase in HR was 24±12 bpm at the beginning of HUTT, 30±14 bpm at 3 minutes of HUTT, 32±13 bpm at 5 minutes of HUTT, and 38±12 bpm at 10 minutes of HUTT. The average maximal HR increase within the first 10 minutes of HUTT was 43±10 bpm. Conclusions: In children with POTS, the HR variability gradually increases with time, and therefore, it is suggested that HR increase ≥40 bpm is more suitable for diagnosis of POTS in children. KW - Child KW - Head-up tilt test KW - Heart rate KW - Orthostatic tachycardia syndrome N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84947228927&doi=10.7499%2fj.issn.1008-8830.2015.10.010&partnerID=40&md5=c77282e3c35be497be68f2e5c7171035 ER - TY - JOUR TI - Postural Tachycardia Syndrome: Beyond Orthostatic Intolerance T2 - Current Neurology and Neuroscience Reports VL - 15 IS - 9 PY - 2015 DO - 10.1007/s11910-015-0583-8 AU - Garland, E.M. AU - Celedonio, J.E. AU - Raj, S.R. AD - Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, TN, United States AD - Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, United States AD - Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, United States AD - Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, University of Calgary, GAC70, HRIC Building, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada AD - Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University, 1161 21st Avenue South, Nashville, TN 37232-2195, United States AD - Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University, 536 Robinson Research Building, 2222 Pierce Avenue, Nashville, TN 37232-6602, United States AB - Postural tachycardia syndrome (POTS) is a form of chronic orthostatic intolerance for which the hallmark physiological trait is an excessive increase in heart rate with assumption of upright posture. The orthostatic tachycardia occurs in the absence of orthostatic hypotension and is associated with a >6-month history of symptoms that are relieved by recumbence. The heart rate abnormality and orthostatic symptoms should not be caused by medications that impair autonomic regulation or by debilitating disorders that can cause tachycardia. POTS is a “final common pathway” for a number of overlapping pathophysiologies, including an autonomic neuropathy in the lower body, hypovolemia, elevated sympathetic tone, mast cell activation, deconditioning, and autoantibodies. Not only may patients be affected by more than one of these pathophysiologies but also the phenotype of POTS has similarities to a number of other disorders, e.g., chronic fatigue syndrome, Ehlers-Danlos syndrome, vasovagal syncope, and inappropriate sinus tachycardia. POTS can be treated with a combination of non-pharmacological approaches, a structured exercise training program, and often some pharmacological support. © 2015, Springer Science+Business Media New York. KW - Autonomic KW - Medication KW - Non-pharmacological KW - Orthostatic KW - Tachycardia KW - Treatment N1 - Cited By :42 N1 - Export Date: 11 October 2019 M3 - Review DB - Scopus C7 - 60 UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938883096&doi=10.1007%2fs11910-015-0583-8&partnerID=40&md5=2f7e3dfe95ecb283ef733d92af533b6a ER - TY - JOUR TI - Autonomic activity and biomarker behavior in supine position and after passive postural stress in different orthostatic intolerance syndromes T2 - Revista Portuguesa de Cardiologia VL - 34 IS - 9 SP - 543 EP - 549 PY - 2015 DO - 10.1016/j.repc.2015.03.009 AU - Freitas, J. AU - Azevedo, E. AU - Santos, R. AU - Maciel, M.J. AU - Rocha-Gonçalves, F. AD - Serviço de Cardiologia, Centro Hospitalar São João, Porto, Portugal AD - Serviço de Neurologia, Centro Hospitalar São João, Porto, Portugal AD - Universidade Do Porto, Faculdade de Medicina, Porto, Portugal AB - Introduction and objectives Orthostatic intolerance (OI) syndromes are a confusing topic and determining a specific diagnosis to achieve optimal treatment can be troublesome. We sought to assess biomarker, hemodynamic and autonomic variables in OI patients (autonomic dysfunction [AD], postural orthostatic tachycardia syndrome [POTS] and neurally mediated syncope [NMS]) and healthy controls during supine and head-up tilt position in order to achieve a better diagnosis. Results In response to head-up tilt, patients with AD presented a marked decrease in systolic blood pressure (SBP) (p=0.002), and a blunted increase in heart rate (HR) (p=0.04). Baroreceptor gain was almost absent in supine position and did not change in response to tilt. Patients with POTS had lower values of atrial natriuretic peptide (p=0.03) but similar neurohormonal biomarkers and hemodynamic and baroreceptor function in supine position compared to healthy subjects. However, in response to head-up tilting greater reductions in stroke volume (p=0.008) and baroreceptor gain (p=0.002) and greater rises in HR (p=0.001), total peripheral resistance (p=0.008), low frequency component of SBP variability (LF-SBP) (p=0.003) and plasma noradrenaline (p=0.03) were observed. Patients with NCS had similar biomarkers and autonomic indices to healthy subjects in supine position, but a larger decrease in baroreceptor gain (p=0.007) and a greater rise in LF-SBP (p=0.004) and plasma adrenaline (p=0.003) response to head-up tilting. Conclusion Although different OI syndromes share similar symptoms, including blurred vision, syncope and dizziness particularly during orthostatism, they differ markedly regarding biochemical, autonomic and hemodynamic parameters. Assessment of these differences may be helpful for better diagnosis and management. © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España, S.L.U. All rightsreserved. KW - Autonomic nervous system KW - Biomarkers KW - Orthostatic intolerance KW - Tilt test N1 - Cited By :2 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84941415097&doi=10.1016%2fj.repc.2015.03.009&partnerID=40&md5=c16fec3e1c221e0f7bab454a90931ae9 ER - TY - JOUR TI - POTS following traumatic stress: Interacting central and intracardiac neural control? T2 - Journal of Diabetes and its Complications VL - 29 IS - 3 SP - 459 EP - 461 PY - 2015 DO - 10.1016/j.jdiacomp.2015.02.003 AU - Meyer, C. AU - Mühlsteff, J. AU - Drexel, T. AU - Eickholt, C. AU - Kelm, M. AU - Zahiragic, L. AU - Ziegler, D. AD - Department of Cardiology/Electrophysiology, University Heart Center, University Hospital Eppendorf, Martinistr. 52, Hamburg, 20246, Germany AD - DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg, Kiel/Lübeck, Germany AD - Department of Cardiology, Pulmology and Angiology, Heinrich-Heine-University, Duesseldorf, Germany AD - Philips Research Europe, Patient Care Solutions, Eindhoven, Netherlands AD - Institute for Clinical Diabetology, German Diabetes Center, Heinrich Heine University, Duesseldorf, Germany AD - Department of Metabolic Diseases, Heinrich Heine University, Duesseldorf, Germany AB - Cardiovascular autonomic dysfunction is one of the most overlooked complications in patients with diabetes. We report the case of a 19-year-old woman with a 4-year history of diabetes referred due to palpitations and light-headedness following traumatic stress. Rise of heart rate and blood pressure during tilt table testing indicated hyperadrenergic postural orthstatic tachycardia syndrome (POTS). Elevated blood pressure variability, an indirect parameter of increased sympathetic activity, remained almost stable during orthostatic stress. Short-term treatment with ivabradine in combination with psychosocial support alleviated POTS-related symptoms. Our findings suggest that traumatic stress in patients with type 1 diabetes mellitus might translate into disturbed neural heart rate control due to a central, ephemeral alteration in autonomic balance. © 2015 Elsevier Inc. All rights reserved. KW - Autonomic balance KW - Cardiac autonomic neuropathy KW - HCN channels KW - POTS KW - Sinus tachycardia KW - Sympathetic nervous system N1 - Cited By :3 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84925349667&doi=10.1016%2fj.jdiacomp.2015.02.003&partnerID=40&md5=59a090f6e29f1e82eb2906c871b8f4cb ER - TY - JOUR TI - Characterisation of sleep disturbances in postural orthostatic tachycardia syndrome: A polysomnography-based study T2 - Sleep Medicine VL - 16 IS - 12 SP - 1457 EP - 1461 PY - 2015 DO - 10.1016/j.sleep.2015.08.003 AU - Pengo, M.F. AU - Higgins, S. AU - Drakatos, P. AU - Martin, K. AU - Gall, N. AU - Rossi, G.P. AU - Leschziner, G. AD - Guy's and St. Thomas' NHS Foundation Trust, Sleep Disorders Centre, London, United Kingdom AD - Department of Medicine (DIMED), University of Padua, Padua, Italy AD - Department of Cardiology, King's College London Hospital, Denmark Hill, London, United Kingdom AD - Department of Clinical Neuroscience, Institute of Psychiatry, King's College London, London, United Kingdom AB - Background and Aim: Postural orthostatic tachycardia syndrome (PoTS) has been frequently associated with sleep disturbances but objective sleep data are lacking. In addition, although regional autonomic denervation has been described, less is known about autonomic nervous activity overnight in these patients. Patients/Methods: A full polysomnography and heart rate variability were performed on 37 patients diagnosed with PoTS In addition, a multiple sleep latency test (MSLT) was conducted on a subgroup of patients with excessive daytime sleepiness. Results: The polysomnographic data did not show major pathological findings except the percentage spent in rapid eye movement (REM) sleep which was slightly reduced at 18.4%. The MSLT did not confirm excessive daytime sleepiness as median mean sleep latency was 14.4 min (11.8-17.5). When comparing patients with and without subjective daytime sleepiness, it was found that the latter had a reduced parasympathetic activation at night as expressed by the average high frequency [6936.5 ms2 (6028.2-8675.5) vs. 4689.5 (3922.7-7685.2) p < 0.05]. Conclusion: Patients with PoTS do not exhibit polysomnographic findings consistent with relevant sleep pathologies nor objective daytime sleepiness. Subjective daytime sleepiness is associated with enhanced activation of the parasympathetic nervous system. © 2015 Elsevier B.V. KW - Autonomic nervous system KW - Heart rate KW - Heart rate variability KW - PoTS KW - Sleep latency N1 - Cited By :11 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84947808408&doi=10.1016%2fj.sleep.2015.08.003&partnerID=40&md5=f3b8dd25af33574dbe12036761475fd2 ER - TY - JOUR TI - Sympathetic activation is associated with increased IL-6, but not CRP in the absence of obesity: Lessons from postural tachycardia syndrome and obesity T2 - American Journal of Physiology - Heart and Circulatory Physiology VL - 309 IS - 12 SP - H2098 EP - H2107 PY - 2015 DO - 10.1152/ajpheart.00409.2015 AU - Okamoto, L.E. AU - Raj, S.R. AU - Gamboa, A. AU - Shibao, C.A. AU - Arnold, A.C. AU - Garland, E.M. AU - Black, B.K. AU - Farley, G. AU - Diedrich, A. AU - Biaggioni, I. AD - Vanderbilt Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, TN, United States AD - Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, United States AD - Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, United States AD - Department of Pharmacology, Vanderbilt University School of Medicine, United States AD - Department of Biomedical Engineering, Vanderbilt University School of Medicine, Nashville, TN, United States AB - Sympathetic activation is thought to contribute to the inflammatory process associated with obesity, which is characterized by elevated circulating C-reactive protein (hsCRP) and interleukin-6 (IL-6). To evaluate whether sympathetic activation is associated with inflammation in the absence of obesity, we studied patients with postural tachycardia syndrome (POTS), a condition characterized by increased sympathetic tone in otherwise healthy individuals. Compared with 23 lean controls, 43 lean female POTS had greater vascular sympathetic modulation (low-frequency blood pressure variability, LFSBP, 3.2 ± 0.4 vs. 5.5 ± 0.6 mmHg2, respectively, P = 0.006), lower cardiac parasympathetic modulation (high-frequency heart rate variability, 1,414 ± 398 vs. 369 ± 66 ms2, P = 0.001), and increased serum IL-6 (2.33 ± 0.49 vs. 4.15 ± 0.54 pg/ml, P = 0.011), but this was not associated with increases in hsCRP, which was low in both groups (0.69 ± 0.15 vs. 0.82 ± 0.16 mg/l, P = 0.736). To explore the contribution of adiposity to inflammation, we then compared 13 obese female POTS patients and 17 obese female controls to matched lean counterparts (13 POTS and 11 controls). Compared with lean controls, obese controls had increased LFSBP (3.3 ± 0.5 vs. 7.0 ± 1.1 mmHg2; P = 0.016), IL-6 (2.15 ± 0.58 vs. 3.92 ± 0.43 pg/ml; P = 0.030) and hsCRP (0.69 ± 0.20 vs. 3.47 ± 0.72 mg/l; P = 0.001). Obese and lean POTS had similarly high IL-6 but only obese POTS had increased hsCRP (5.76 ± 1.99 mg/l vs. 0.65 ± 0.26; P < 0.001). In conclusion, sympathetic activation in POTS is associated with increased IL-6 even in the absence of obesity. The coupling between IL-6 and CRP, however, requires increased adiposity, likely through release of IL-6 by visceral fat. © 2015 the American Physiological Society. KW - Autonomic nervous system KW - Chronic fatigue syndrome KW - Inflammation KW - Obesity KW - Postural tachycardia syndrome N1 - Cited By :8 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84949771929&doi=10.1152%2fajpheart.00409.2015&partnerID=40&md5=e23f0f346a297bcf5114c85cc0865d83 ER - TY - JOUR TI - A prospective study of excessive postural heart rate change on head-up tilt T2 - Clinical Autonomic Research VL - 24 IS - 6 SP - 253 EP - 258 PY - 2014 DO - 10.1007/s10286-014-0254-x AU - Corkal, J.C. AU - Kimpinski, K. AD - Department of Clinical Neurological Sciences, London Health Sciences Centre, University Hospital, Rm. C7-131, 339 Windermere Road, London, ON N6A 5A5, Canada AD - Schulich School of Medicine and Dentistry, Western University, London, ON, Canada AB - Methods: Subjects were evaluated at baseline and at 1 year using the autonomic reflex screen and autonomic symptom profile (ASP). Purpose: Healthy subjects with asymptomatic postural tachycardia (≥30 bpm) at baseline were evaluated over a 1-year period to determine whether they developed orthostatic symptoms. Results: Heart rate increment on HUT did not differ at baseline (40.6 ± 7.5 bpm) or at 1 year (37.1 ± 11.1 bpm; n = 26; p > 0.05). Orthostatic symptoms measured by the ASP did not reveal significant orthostatic dysfunction throughout follow-up (baseline, 7.88 ± 7.61; 1 year, 9.04 ± 6.64; n = 26; p > 0.05). The ten autonomic domains of the ASP did not reveal a change in autonomic symptoms from baseline (13.56 ± 13.66) to 1-year follow-up (15.12 ± 11.62; n = 26; p > 0.05). Cardiovagal function was unchanged between baseline and follow-up for both heart rate variability to deep breathing (baseline, 23.9 ± 11.6 bpm; 1 year, 23.0 ± 9.3 bpm; n = 26; p > 0.05) and Valsalva ratio (baseline, 2.16 ± 0.39; 1 year, 2.15 ± 0.33; n = 26; p > 0.05). Conclusions: These findings further argue that heart rate criteria (≥30 bpm) for Postural Tachycardia Syndrome (POTS) are not appropriate in younger individuals and higher postural heart rates do not predispose individuals to the development of POTS. © 2014, Springer-Verlag Berlin Heidelberg. KW - Aging KW - Autonomic nervous system KW - Autonomic neuropathy KW - Orthostatic intolerance KW - Postural orthostatic tachycardia syndrome N1 - Cited By :2 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84919768228&doi=10.1007%2fs10286-014-0254-x&partnerID=40&md5=e77ce4c429e1a15d67b214a72b9e97f2 ER - TY - JOUR TI - Sleep disturbances and autonomic dysfunction in patients with postural orthostatic tachycardia syndrome T2 - Frontiers in Neurology VL - 5 JUL PY - 2014 DO - 10.3389/fneur.2014.00118 AU - Mallien, J. AU - Isenmann, S. AU - Mrazek, A. AU - Haensch, C.-A. AD - Sleep Unit, Department of Neurology and Neurophysiology, HELIOS Klinikum Wuppertal, University of Witten/Herdecke, Wuppertal, Germany AD - Department of Neurology, Kliniken Maria Hilf GmbH, University of Witten/Herdecke, Mönchengladbach, Germany AB - Many patients with postural tachycardia syndrome (PoTS) suffer from fatigue, daytime sleepiness, and sleeping disturbances. The objective of this study was to compare subjective and objective sleep quality of PoTS patients with a group of healthy controls. All patients completed a Pittsburgh Sleep Quality Index questionnaire and the Epworth Sleepiness Scale. The patients sleep architecture, heart rate, and heart rate variability (HRV) measurements were taken during one night at the sleep laboratorium. All data was collected at the Sleep Unit, at Helios Klinikum Wuppertal. Thirty-eight patients diagnosed with PoTS were compared to 31 healthy controls, matched in age and gender. Patients with PoTS reached significantly higher scores in sleep questionnaires, which means that they were more sleepy and had a lower sleep quality. Polysomnography showed a significantly higher proportion of stage 2 sleep. The results of HRV analysis in different sleep stages confirmed changes in autonomic activity in both groups. PoTS patients, however, showed a diminished variability of the low-frequency (LF) band, high-frequency (HF) band, and LF/HF ratio in different sleep stages. It can therefore be gathered that PoTS could be considered as potential differential diagnosis for sleep disturbances since PoTS patients had a subjective diminished sleep quality, reached higher levels of daytime sleepiness, and showed a higher proportion of stage 2 sleep. PoTS patients showed furthermore a reduction of LF/HF ratio variability in different sleep stages. © 2014 Mallien, Isenmann, Mrazek and Haensch. KW - Autonomic dysfunction KW - Heart rate variability KW - Insomnia KW - PoTS KW - Sleep disturbances N1 - Cited By :19 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus C7 - 118 UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904406618&doi=10.3389%2ffneur.2014.00118&partnerID=40&md5=6690239352c2e2b15b37a58b2ef95f54 ER - TY - JOUR TI - Comorbidity of postural orthostatic tachycardia syndrome and chronic fatigue syndrome in an Australian cohort T2 - Journal of Internal Medicine VL - 275 IS - 4 SP - 409 EP - 417 PY - 2014 DO - 10.1111/joim.12161 AU - Reynolds, G.K. AU - Lewis, D.P. AU - Richardson, A.M. AU - Lidbury, B.A. AD - Department of Genome Biology, John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia AD - CFS Discovery, Donvale Medical Centre, Donvale, VIC, Australia AD - Faculty of Education, Science, Technology and Mathematics, University of Canberra, Canberra, ACT, Australia AB - Objective: Patients with chronic fatigue syndrome (CFS) are frequently diagnosed with comorbid postural orthostatic tachycardia syndrome (POTS), suggesting a shared pathogenesis. The aim of this study was to examine the relationship between demographic characteristics, autonomic functioning and fatigue levels amongst CFS patients with and without comorbid POTS. Design and setting: All patients presenting to the CFS Discovery Clinic between 2009 and 2012 completed a 20-min standing task as part of their initial assessment. Heart rate and pulse pressure were recorded at baseline, at 2-min intervals poststanding, at the end of the task and following a recovery period. Average heart rate and pulse pressure variability were calculated from this data. Age, gender, length of illness and self-reported fatigue scores were also recorded. POTS patients were diagnosed by an orthostatic increase in heart rate >30 beats per min, concomitant symptoms of orthostatic intolerance and no orthostatic hypotension. Differences in autonomic functioning between POTS and CFS patients were compared using independent samples t-tests, whilst logistic and linear regressions were performed to examine the contribution of autonomic functioning to task completion and perceived fatigue, respectively. Results: Comorbidity of CFS and POTS (CFS-POTS) was observed in 11% (33/306) of patients. CFS-POTS patients were significantly younger (P < 0.001), had a shorter length of illness (P = 0.034), experienced greater task difficulty (P = 0.002) and were able to stand for significantly shorter periods compared to the CFS-only patients (P < 0.001). CFS-POTS patients experienced significantly lower baseline diastolic blood pressure (P = 0.002), significantly higher heart rate and lower pulse pressures at each standing measurement. Early heart rate changes (P = 0.002) and overall heart rate change (P < 0.001) were significant predictors of completion status, whereas heart rate variability (P < 0.001) and female gender (P < 0.001) were significant predictors of increased perceived task difficulty. Conclusions: Haemodynamic and demographic differences between CFS-POTS and CFS-only patients suggest that the former group reflects a distinct subgroup of the CFS population. The findings highlight the utility of screening younger patients with fatigue for POTS, and identified heart rate variability as an important marker of fatigue for CFS patients in general. © 2013 The Association for the Publication of the Journal of Internal Medicine. KW - Autonomic function KW - Chronic fatigue syndrome KW - Fatigue syndromes KW - Postural orthostatic tachycardia syndrome KW - Standing test N1 - Cited By :31 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84897027028&doi=10.1111%2fjoim.12161&partnerID=40&md5=9013049ea7024a0a45ebbccd7932206f ER - TY - JOUR TI - Variant cardiovascular regulation in children with postural tachycardia syndrome T2 - Pediatrics International VL - 56 IS - 3 SP - 328 EP - 335 PY - 2014 DO - 10.1111/ped.12284 AU - Yoshida, S. AU - Tanaka, H. AU - Nakao, R. AU - Okamoto, N. AU - Kajiura, M. AU - Kanbara, Y. AU - Azuma, S. AU - Tamai, H. AD - Department of Pediatrics, Osaka Medical College, 2-7, Daigakumachi, Takatsuki, Osaka 569-8686, Japan AD - Department of Pediatrics, Yao Tokushukai Hospital, Yao, Japan AB - Background Postural tachycardia syndrome (POTS) manifests as marked tachycardia while standing. We noticed two forms of circulatory response to orthostatic stress in POTS. We investigated cardiovascular and autonomic nervous response to orthostatic stress in the two forms. Methods We studied 79 patients with POTS and 38 healthy control subjects (Ct). Beat-to-beat blood pressure (BP) and heart rate (HR) were non-invasively and continuously measured in the supine and standing positions. Autonomic nervous function was evaluated on power spectral analysis of HR variability and diastolic BP variability. We divided the subjects into two groups: standing-induced tachycardia (SI group; increase in HR ≥35 beats/min) and supine tachycardia (Su group; standing HR ≥115 beats/min with standing-induced HR increase <35 beats/min). Results The Su group had higher supine BP and HR compared with the other groups, indicating dominant sympathetic control of the heart in the supine position. While rising, the SI group had a higher increase in HR than the Ct group, indicating excessive withdrawal of vagal tone. The Su group had a smaller increase in HR and a greater decrease of systolic BP and cardiac index by standing compared with the SI group. These results suggest that compensatory mechanisms of sympathetic function during standing failed in the Su group, probably because of exhaustion by the nearly maximum effort to generate sympathetic drive even in the supine position with low central blood volume. Conclusion There is a difference between the two types of POTS, in the balance of resting autonomic function and hemodynamic response to standing. © 2014 Japan Pediatric Society. KW - continuous tachycardia KW - standing-induced tachycardia N1 - Cited By :4 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84901848470&doi=10.1111%2fped.12284&partnerID=40&md5=a99e41378320226e732daeae081f435e ER - TY - JOUR TI - Understanding the placebo effect in clinical trials for postural tachycardia syndrome T2 - Clinical and Experimental Pharmacology and Physiology VL - 41 IS - 5 SP - 325 EP - 330 PY - 2014 DO - 10.1111/1440-1681.12221 AU - Nwazue, V.C. AU - Arnold, A.C. AU - Raj, V. AU - Black, B.K. AU - Biaggioni, I. AU - Paranjape, S.Y. AU - Orozco, C. AU - Dupont, W.D. AU - Robertson, D. AU - Raj, S.R. AD - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University, Nashville, TN, United States AD - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of Psychiatry, Vanderbilt University, Nashville, TN, United States AD - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University, Nashville, TN, United States AD - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of Biostatistics, Vanderbilt University, Nashville, TN, United States AD - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of Neurology, Vanderbilt University, Nashville, TN, United States AB - Summary: Postural tachycardia syndrome (POTS) is characterized by excessive increases in heart rate (HR) upon standing. Previous studies have shown that standing HR decreases over time in POTS patients given placebo. We hypothesized that this reduction is due to cardiovascular physiological alteration, as opposed to psychological benefit from perceived therapy. To prospectively test this hypothesis, we examined the effects of an open-label 'no treatment' intervention (NoRx) compared with a patient-blinded placebo on standing HR in POTS patients. Twenty-one POTS patients participated in a randomized cross-over trial with oral placebo versus NoRx administered at 0900 h. Seated blood pressure (BP) and HR were measured at baseline and every hour for 4 h. Similarly, BP and HR were measured while patients stood for 10 min at these time points. Standing HR decreased significantly over time with both NoRx (112 ± 13 and 103 ± 16 b.p.m. at baseline and 4 h, respectively) and placebo (112 ± 14 and 102 ± 16 b.p.m. at baseline and 4 h, respectively; Ptime < 0.001), but this effect was not different between interventions (Pdrug = 0.771). Postural tachycardia syndrome patients have exaggerated orthostatic tachycardia in the morning that decreases over time with either placebo or NoRx interventions, suggesting this phenomenon is due to cardiovascular physiological variation. These data highlight the need for a placebo arm in haemodynamic clinical trials in POTS and may have important implications for the diagnosis of these patients. © 2014 Wiley Publishing Asia Pty Ltd. KW - Diurnal variability KW - Placebo KW - Postural tachycardia syndrome N1 - Cited By :5 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899114899&doi=10.1111%2f1440-1681.12221&partnerID=40&md5=d46de64700cb73dd3fe74ce3cd867877 ER - TY - JOUR TI - Postural tachycardia syndrome following human papillomavirus vaccination T2 - European Journal of Neurology VL - 21 IS - 1 SP - 135 EP - 139 PY - 2014 DO - 10.1111/ene.12272 AU - Blitshteyn, S. AD - Department of Neurology, State University of New York at Buffalo School of Medicine and Biomedical Sciences, Buffalo, NY, United States AB - Background and purpose: Postural tachycardia syndrome (POTS) is a heterogeneous disorder of the autonomic nervous system that may have an autoimmune etiology. Methods: Six patients who developed new onset POTS 6 days to 2 months following human papillomavirus vaccination are reported. Results: Three patients also had neurocardiogenic syncope, and three patients were diagnosed with possible small fiber neuropathy. Symptoms in all patients improved over 3 years with pharmacotherapy and non-pharmacological measures but residual symptoms persisted. Molecular mimicry with formation of cross-reacting autoantibodies to the potential targets of the autonomic ganglia, neurons, cardiac proteins or vascular receptors is considered as a possible pathogenesis of new onset POTS after immunization. Conclusion: Correct diagnosis of POTS and awareness that POTS may occur after vaccination in young women is essential for prompt and effective management of this condition. © 2013 EFNS. KW - Disorders of the autonomic nervous system KW - Human papillomavirus vaccination KW - Neuropathy KW - Postural tachycardia syndrome KW - Small fibers KW - Vaccination N1 - Cited By :46 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84890123079&doi=10.1111%2fene.12272&partnerID=40&md5=1b59ba0724c8adc57cdf89eeaca155c3 ER - TY - JOUR TI - Altered oscillatory cerebral blood flow velocity and autoregulation in postural tachycardia syndrome T2 - Frontiers in Physiology VL - 5 JUN PY - 2014 DO - 10.3389/fphys.2014.00234 AU - Medow, M.S. AU - Del Pozzi, A.T. AU - Messer, Z.R. AU - Terilli, C. AU - Stewart, J.M. AD - Departments of Pediatrics, The Center for Hypotension, New York Medical College, Valhalla, NY, United States AD - Departments of Physiology, New York Medical College, Valhalla, NY, United States AB - Decreased upright cerebral blood flow (CBF) with hyperpnea and hypocapnia is seen in a minority of patients with postural tachycardia syndrome (POTS). More often, CBF is not decreased despite upright neurocognitive dysfunction. This may result from time-dependent changes in CBF. We hypothesized that increased oscillations in CBF occurs in POTS (N = 12) compared to healthy controls (N = 9), and tested by measuring CBF velocity (CBFv) by transcranial Doppler ultrasound of the middle cerebral artery, mean arterial pressure (MAP) and related parameters, supine and during 70° upright tilt. Autospectra for mean CBFv and MAP, and transfer function analysis were obtained over the frequency range of 0.0078-0.4 Hz. Upright HR was increased in POTS (125 ± 8 vs. 86 ± 2 bpm), as was diastolic BP (74 ± 3 vs. 65 ± 3 mmHg) compared to control, while peripheral resistance, cardiac output, and mean CBFv increased similarly with tilt. Upright BP variability (BPV), low frequency (LF) power (0.04-0.13 Hz), and peak frequency of BPV were increased in POTS (24.3 ± 4.1, and 18.4 ± 4.1 mmHg2/Hz at 0.091 Hz vs. 11.8 ± 3.3, and 8.8 ± 2 mmHg2/Hz c at 0.071 Hz), as was upright overall CBFv variability, low frequency power and peak frequency of CBFv variability (29.3 ± 4.7, and 22.1 ± 2.7 [cm/s]2/Hz at.092 Hz vs. 14.7 ± 2.6, and 6.7 ± 1.2 [cm/s]2/Hz at 0.077Hz). Autospectra were sharply peaked in POTS. LF phase was decreased in POTS (-14 ± 4 vs. -25 ± 10 degrees) while upright. LF gain was increased (1.51 ± 0.09 vs. 0.86 ± 0.12 [cm/s]/mmHg) while coherence was increased (0.96 ± 0.01 vs. 0.80 ± 0.04). Increased oscillatory BP in upright POTS patients is closely coupled to oscillatory CBFv over a narrow bandwidth corresponding to the Mayer wave frequency. Therefore combined increased oscillatory BP and increased LF gain markedly increases CBFv oscillations in a narrow bandwidth. This close coupling of CBF to MAP indicates impaired cerebral autoregulation that may underlie upright neurocognitive dysfunction in POTS. © 2014 Medow, Del Pozzi, Messer, Terilli and Stewart. KW - Cerebral blood flow KW - Mean arterial pressure autospectra KW - Mean cerebral blood flow velocity autospectra KW - Postural tachycardia syndrome KW - Transfer function analysis KW - Vasomotion N1 - Cited By :8 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus C7 - Article 234 UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904392932&doi=10.3389%2ffphys.2014.00234&partnerID=40&md5=4ec42a9aa3dd3d05cba60ac3f155d48c ER - TY - JOUR TI - Estimation of sleep disturbances using wrist actigraphy in patients with postural tachycardia syndrome T2 - Autonomic Neuroscience: Basic and Clinical VL - 177 IS - 2 SP - 260 EP - 265 PY - 2013 DO - 10.1016/j.autneu.2013.02.021 AU - Bagai, K. AU - Wakwe, C.I. AU - Malow, B. AU - Black, B.K. AU - Biaggioni, I. AU - Paranjape, S.Y. AU - Orozco, C. AU - Raj, S.R. AD - Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, TN, United States AD - Department of Neurology, Vanderbilt University School of Medicine, Nashville, TN, United States AD - Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, United States AD - Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, United States AB - Study objectives: Patients with postural tachycardia syndrome (POTS) commonly complain of fatigue, unrefreshing sleep, daytime sleepiness and diminished quality of life. The study objective was to assess sleep quality in POTS patients using wrist actigraphy. Design: Prospective study with control group. Methods: Patients with POTS (n = 36) and healthy subjects (n = 36) completed a detailed sleep log and actigraphy for 7. days. Results: Compared with healthy subjects, POTS patients have more self-reported problems including days with restless sleep (53±30% vs. 21±20%; P<0.001) and tiredness (75±23% vs. 39±27%; P<0.001). Using actigraphy, POTS patients have lower sleep efficiency (73±13% vs. 79±6%; P=0.01). Actigraphy determined sleep onset latency (SOL) did not vary significantly in the two groups, but subjective SOL was higher in POTS patient (56±66min vs. 13±9min; P=0.001). In POTS patients, there was a significant correlation between subjective complaints of tiredness and actigraphic sleep efficiency (Rs=-0.36; R2=0.15; P=0.01), significant correlations between actigraphic SOL and upright norepinephrine levels (P=0.040), and between wake after sleep onset and standing heart rate (P=0.02). Conclusions: POTS patients have more sleep-related symptoms and poor sleep efficiency. The pattern of subjective vs. objective SOL mismatch is suggestive of sleep-state misperception. High norepinephrine correlated with actigraphic SOL, and this activation of the stress system may contribute significantly to a hyperarousal state with consequent insomnia, poor mental and physical health in POTS patients. © 2013 Elsevier B.V. KW - Actigraphy KW - Autonomic KW - Human KW - Orthostatic tachycardia KW - Sleep N1 - Cited By :22 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84883796954&doi=10.1016%2fj.autneu.2013.02.021&partnerID=40&md5=8e0d757f013a50dfc8b056dbe772bfbf ER - TY - JOUR TI - Characteristics of heart rate reduction with resumption of supine position in the postural tachycardia syndrome: Factors influencing recovery T2 - Open Cardiovascular Medicine Journal VL - 7 IS - 1 SP - 36 EP - 39 PY - 2013 DO - 10.2174/1874192401307010036 AU - Mayuga, K.A. AU - Gaw, C.E. AU - Tatsuoka, C. AU - Fouad-Tarazi, F. AD - Heart and Vascular Institute, Dept. of Cardiovascular Medicine, Cleveland Clinic, 9500 Euclid Ave, Desk J2-2, Cleveland, OH 44195, United States AB - Objectives: Postural orthostatic tachycardia syndrome (POTS), a heart rate (HR) rise with upright positioning, is dependent on autonomic influences. HR recovery (HR decrease after exercise cessation) is a measure of autonomic function. Characteristics of HR reduction during supine Recovery after head-up Tilt in POTS patients have not been elucidated. Methods: 113 subjects (mean age 41.7 years, 86 female), diagnosed with POTS on head-up Tilt were analyzed. HR's were recorded during baseline supine position, 70-degree Tilt, and 20 sec, 1 min and 2 min of supine Recovery. Percent HR reduction during Recovery was calculated. Results: Baseline HR was 68.7±13.4 bpm. Maximum HR during Tilt was 109±16.9 bpm. Mean HR was 84.2±20 bpm at 20 sec, 78.5±18.9 bpm at 1-min, and 77.1±18.3 bpm at 2 min of Recovery. Younger age and slower baseline HR were associated with greater HR reductions at 20 sec (p=0.006, p=0.000, respectively). Younger age, slower baseline HR and less time to achieve POTS were associated with greater HR reductions at 1 min (p=0.025, p=0.000, p=0.000, respectively) and at 2 min (p=0.004, p=0.000, p=0.000, respectively). Gender and baseline blood pressures were not significant. Conclusions: In POTS patients, HR quickly decreases upon resuming supine position. Younger age, slower baseline HR and less time to achieve POTS were associated with greater HR reductions during supine Recovery. Further study is needed to determine mechanisms, as well as analyze differences in symptoms or prognosis. © Mayuga et al.; Licensee Bentham Open. KW - Heart rate recovery KW - Postural orthostatic tachycardia syndrome KW - Syncope KW - Tilt table test N1 - Cited By :1 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879153640&doi=10.2174%2f1874192401307010036&partnerID=40&md5=f5ce7ee2dbff1ce348e26e9841e387ae ER - TY - JOUR TI - Clinical characteristics of a novel subgroup of chronic fatigue syndrome patients with postural orthostatic tachycardia syndrome T2 - Journal of Internal Medicine VL - 273 IS - 5 SP - 501 EP - 510 PY - 2013 DO - 10.1111/joim.12022 AU - Lewis, I. AU - Pairman, J. AU - Spickett, G. AU - Newton, J.L. AD - Institute for Ageing and Health, Newcastle University, Newcastle, United Kingdom AD - Northern CFS Clinical Network, Newcastle Hospitals NHS Foundation Trust, Newcastle, United Kingdom AD - UK NIHR Biomedical Research Centre in Ageing, Newcastle University, Newcastle, United Kingdom AB - Objectives: A significant proportion of patients with chronic fatigue syndrome (CFS) also have postural orthostatic tachycardia syndrome (POTS). We aimed to characterize these patients and differentiate them from CFS patients without POTS in terms of clinical and autonomic features. Methods: A total of 179 patients with CFS (1994 Centers for Disease Control and Prevention criteria) attending one of the largest Department of Health-funded CFS clinical services were included in this study. Outcome measures were as follows: (i) symptom assessment tools including the fatigue impact scale, Chalder fatigue scale, Epworth sleepiness scale (ESS), orthostatic grading scale (OGS) and hospital anxiety and depression scale (HADS-A and -D, respectively), (ii) autonomic function analysis including heart rate variability and (iii) haemodynamic responses including left ventricular ejection time and systolic blood pressure drop upon standing. Results: CFS patients with POTS (13%, n = 24) were younger (29 ± 12 vs. 42 ± 13 years, P < 0.0001), less fatigued (Chalder fatigue scale, 8 ± 4 vs. 10 ± 2, P = 0.002), less depressed (HADS-D, 6 ± 4 vs. 9 ± 4, P = 0.01) and had reduced daytime hypersomnolence (ESS, 7 ± 6 vs. 10 ± 5, P = 0.02), compared with patients without POTS. In addition, they exhibited greater orthostatic intolerance (OGS, 11 ± 5; P < 0.0001) and autonomic dysfunction. A combined clinical assessment tool of ESS ≤9 and OGS ≥9 identifies accurately CFS patients with POTS with 100% positive and negative predictive values. Conclusions: The presence of POTS marks a distinct clinical group of CFS patents, with phenotypic features differentiating them from those without POTS. A combination of validated clinical assessment tools can determine which CFS patients have POTS with a high degree of accuracy, and thus potentially identify those who require further investigation and consideration for therapy to control heart rate. © 2013 The Association for the Publication of the Journal of Internal Medicine. KW - Autonomic dysfunction KW - Chronic fatigue syndrome KW - Dysautonomia KW - Postural orthostatic tachycardia syndrome N1 - Cited By :40 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876743948&doi=10.1111%2fjoim.12022&partnerID=40&md5=6640c8f6280afa6078969a524f204770 ER - TY - JOUR TI - Diagnosing postural tachycardia syndrome: Comparison of tilt testing compared with standing haemodynamics T2 - Clinical Science VL - 124 IS - 2 SP - 109 EP - 114 PY - 2013 DO - 10.1042/CS20120276 AU - Plash, W.B. AU - Diedrich, A. AU - Biaggioni, I. AU - Garland, E.M. AU - Paranjape, S.Y. AU - Black, B.K. AU - Dupont, W.D. AU - Raj, S.R. AD - Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, TN 37232-2195, United States AD - Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232-2195, United States AD - Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-2195, United States AD - Department of Biomedical Engineering, Vanderbilt University School of Medicine, Nashville, TN 37232-2195, United States AD - Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232-2195, United States AD - Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN 37232-2195, United States AB - POTS (postural tachycardia syndrome) is characterized by an increased heart rate (δHR) of ≥30 bpm (beats/min) with symptoms related to upright posture. Active stand (STAND) and passive head-up tilt (TILT) produce different physiological responses. We hypothesized these different responses would affect the ability of individuals to achieve the POTS HR increase criterion. Patients with POTS (n=15) and healthy controls (n=15) underwent 30 min of tilt and stand testing. δHR values were analysed at 5 min intervals. ROC (receiver operating characteristic) analysis was performed to determine optimal cut point values of δHR for both tilt and stand. Tilt produced larger δHR than stand for all 5 min intervals from 5 min (38± 3 bpm compared with 33± 3 bpm; P= 0.03) to 30 min (51±3 bpm compared with 38± 3 bpm; P<0.001). Sn (sensitivity) of the 30 bpm criterion was similar for all tests (TILT10=93%, STAND10=87%, TILT30=100%, and STAND30=93%). Sp (specificity) of the 30 bpm criterion was less at both 10 and 30 min for tilt (TILT10=40%, TILT30=20%) than stand (STAND10=67%, STAND30=53%). The optimal δHR to discriminate POTS at 10 min were 38 bpm (TILT) and 29 bpm (STAND), and at 30 min were 47 bpm (TILT) and 34 bpm (STAND). Orthostatic tachycardia was greater for tilt (with lower Sp for POTS diagnosis) than stand at 10 and 30 min. The 30 bpm δHR criterion is not suitable for 30 min tilt. Diagnosis of POTS should consider orthostatic intolerance criteria and not be based solely on orthostatic tachycardia regardless of test used. © 2013 Biochemical Society. KW - Heart rate KW - Orthostatic tachycardia KW - Postural tachycardia syndrome KW - Stand KW - Tilt table test N1 - Cited By :31 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84870522867&doi=10.1042%2fCS20120276&partnerID=40&md5=40acd74034b119a6e96cea1064666dc2 ER - TY - JOUR TI - Postural orthostatic tachycardia syndrome T2 - Neurologia Croatica VL - 61 IS - 3-4 SP - 53 EP - 61 PY - 2012 AU - Crnošija, L. AU - Adamec, I. AU - Mišmaš, A. AU - Habek, M. AD - School of Medicine, University of Zagreb, Zagreb, Croatia AD - Zagreb University Hospital Center, Department of Neurology, Referral Center for Demyelinating Diseases of the Central Nervous System, Kišpatićeva 12, HR-10000 Zagreb, Croatia AB - Orthostatic intolerance can be defined as inability to tolerate upright posture relieved by recumbence. Postural orthostatic tachycardia syndrome (POTS) is a form of orthostatic intolerance defined as sustained increase in heart rate of ≥30 bpm or increase of heart rate to ≥120 bpm within 10 min of standing or head-up tilt associated with symptoms of orthostatic intolerance and absence of orthostatic hypotension. POTS patients are mostly female with 4-5:1 ratio and age range from 15 to 50. Several pathophysiological mechanisms are thought to underlie POTS. Some of the possible mechanisms are distal peripheral neuropathy, abnormalities of central control of sympathetic nervous system, impaired synaptic norepinephrine reuptake, renin-angiotensin-aldosterone axis disturbance and altered norepinephrine synthetic pathway. T e most common symptoms related to POTS are light-headedness, presyncope, weakness and palpitations. Exacerbation of symptoms with standing and symptoms relieved with recumbence is a characteristic feature of POTS. Active stand test and passive head-up tilt table test are used in diagnosing POTS, along with detailed history and examination. Nonpharmacological therapy of POTS includes increase in daily salt and water intake, and exercise training. Pharmacological therapy is directed at expanding fluid volume, increasing peripheral vascular resistance and reducing central sympathetic activity. T e majority of patients experience substantial improvement after correct diagnosis and appropriate therapy. KW - Diagnosis KW - Hyperadrenergic pots KW - Neuropathic pots KW - Orthostatic intolerance KW - Pathophysiology KW - Postural orthostatic tachycardia syndrome (POTS) KW - Therapy N1 - Cited By :4 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84888613978&partnerID=40&md5=5908d3779f004efcab8f05f15e6e5cd0 ER - TY - JOUR TI - GNB3 C825T polymorphism is associated with postural tachycardia syndrome in children T2 - Pediatrics International VL - 54 IS - 6 SP - 829 EP - 837 PY - 2012 DO - 10.1111/j.1442-200X.2012.03707.x AU - Nakao, R. AU - Tanaka, H. AU - Takitani, K. AU - Kajiura, M. AU - Okamoto, N. AU - Kanbara, Y. AU - Tamai, H. AD - Department of Pediatrics, Osaka Medical College, 2-7, Daigakumachi, Takatsuki, Osaka 569-8686, Japan AD - Department of Pediatrics, Yao Tokushukai Hospital, Osaka, Japan AB - Aim: Postural tachycardia syndrome (POTS) is one of the most frequent forms of chronic orthostatic intolerance in children and adolescents. The aim of the present study was to examine the influence of a genetic background on POTS. Methods: A total of 96 children and adolescents with orthostatic dysregulation were studied. The polymorphism of the G protein β3 subunit (GNB3) C825T and G protein α subunit (GNAS1) T131C of genes encoding components of the autonomic nervous system were determined and compared with circulatory responses to active standing. Results: In the GNB3 gene C825T polymorphism, the CT and TT genotype had a significant lower supine heart rate and a larger increase of heart rate by standing than the CC, associated with evaluated power of the high-frequency component of heart rate variability. According to the criteria of the Japanese clinical guidelines, 48 children were diagnosed as POTS and 30 were as normal responder with somatoform disorder (SD). In GNB3 C825T polymorphism, the TT genotype was more frequently found in the POTS group (45.8%) than in the SD group (25.0%; P = 0.036). In the GNAS1 T393C, the genotype frequencies for the T393C polymorphisms of GNA1 did not differ significantly between the groups. Conclusion: The gene polymorphisms GNB3 C825T might be a risk factor for POTS through the enhanced vagal withdrawal of the heart in children and adolescents. © 2012 The Authors. KW - G protein α subunit T131C KW - G protein β3 subunit C825T KW - Gene polymorphism KW - Orthostatic dysregulation KW - Postural tachycardia syndrome N1 - Cited By :4 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84872808817&doi=10.1111%2fj.1442-200X.2012.03707.x&partnerID=40&md5=2776ac03fbbdbe57c6d88e95c678fa14 ER - TY - JOUR TI - POTS due to excessive venous pooling in an enlarged inferior vena cava T2 - Clinical Autonomic Research VL - 22 IS - 4 SP - 197 EP - 198 PY - 2012 DO - 10.1007/s10286-012-0157-7 AU - Gaw, C.E. AU - Shields Jr., R.W. AU - Mayuga, K.A. AU - Gornik, H.L. AU - Fouad-Tarazi, F. AD - Department of Cardiovascular Medicine, Cleveland Clinic, 9500 Euclid Avenue J2-2, Cleveland, OH 44195, United States AB - Postural tachycardia syndrome (POTS) is a form of orthostatic intolerance characterized by a marked increase in heart rate within the first 10 min of head-up tilt (HUT). We present a patient whose enlarged inferior vena cava that appears to be a contributing mechanism to her POTS and presyncopal symptoms. © Springer-Verlag 2012. KW - Coronary artery KW - Inferior vena cava KW - Orthostatic intolerance KW - Postural tachycardia syndrome KW - Venous pooling N1 - Cited By :1 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864968496&doi=10.1007%2fs10286-012-0157-7&partnerID=40&md5=66e5c039eaed76f3403a9f600491b9db ER - TY - JOUR TI - Diurnal variability in orthostatic tachycardia: Implications for the postural tachycardia syndrome T2 - Clinical Science VL - 122 IS - 1 SP - 25 EP - 31 PY - 2012 DO - 10.1042/CS20110077 AU - Brewster, J.A. AU - Garland, E.M. AU - Biaggioni, I. AU - Black, B.K. AU - Ling, J.F. AU - Shibao, C.A. AU - Robertson, D. AU - Raj, S.R. AD - Division of Clinical Pharmacology, Vanderbilt University School of Medicine, AA3228 Medical Center North, 1161 21st Avenue South, Nashville, TN 37232-2195, United States AD - Autonomic Dysfunction Center, Vanderbilt University School of Medicine, AA3228 Medical Center North, 1161 21st Avenue South, Nashville, TN 37232-2195, United States AD - Department of Medicine, Vanderbilt University School of Medicine, AA3228 Medical Center North, 1161 21st Avenue South, Nashville, TN 37232-2195, United States AD - Department of Pharmacology, Vanderbilt University School of Medicine, AA3228 Medical Center North, 1161 21st Avenue South, Nashville, TN 37232-2195, United States AD - Department of Neurology, Vanderbilt University School of Medicine, AA3228 Medical Center North, 1161 21st Avenue South, Nashville, TN 37232-2195, United States AB - Patients with POTS (postural tachycardia syndrome) have excessive orthostatic tachycardia (>30 beats/min) when standing from a supine position. HR (heart rate) and BP (blood pressure) are known to exhibit diurnal variability, but the role of diurnal variability in orthostatic changes of HR and BP is not known. In the present study, we tested the hypothesis that there is diurnal variation of orthostatic HR and BP in patients with POTS and healthy controls. Patients with POTS (n=54) and healthy volunteers (n=26) were admitted to the Clinical Research Center. Supine and standing (5 min) HR and BP were obtained in the evening on the day of admission and in the following morning. Overall, standing HR was significantly higher in the morning (102± 3 beats/min) than in the evening (93± 2 beats/min; P<0.001). Standing HR was higher in the morning in both POTS patients (108± 4 beats/min in the morning compared with 100± 3 beats/min in the evening; P=0.012) and controls (89± 3 beats/min in the morning compared with 80± 2 beats/min in the evening; P=0.005) when analysed separately. There was no diurnal variability in orthostatic BP in POTS. A greater number of subjects met the POTS HR criterion in the morning compared with the evening (P=0.008). There was significant diurnal variability in orthostatic tachycardia, with a great orthostatic tachycardia in the morning compared with the evening in both patients with POTS and healthy subjects. Given the importance of orthostatic tachycardia in diagnosing POTS, this diurnal variability should be considered in the clinic as it may affect the diagnosis of POTS. © The Authors Journal compilation © 2012 Biochemical Society. KW - Blood pressure KW - Circadian variation KW - Diurnal variability KW - Heart rate KW - Orthostatic intolerance KW - Postural tachycardia syndrome (POTS) N1 - Cited By :21 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84856373588&doi=10.1042%2fCS20110077&partnerID=40&md5=1c2fbccfedaa33e12f4adb9c1bf8eaa5 ER - TY - JOUR TI - Postural tachycardia syndrome - Current experience and concepts T2 - Nature Reviews Neurology VL - 8 IS - 1 SP - 22 EP - 34 PY - 2012 DO - 10.1038/nrneurol.2011.187 AU - Mathias, C.J. AU - Low, D.A. AU - Iodice, V. AU - Owens, A.P. AU - Kirbis, M. AU - Grahame, R. AD - Autonomic and Neurovascular Medicine Unit, Imperial College London, St. Mary's Hospital, Queen Elizabeth the Queen Mother Wing, Praed Street, London W2 1NY, United Kingdom AD - Autonomic Unit, University College London Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, United Kingdom AD - Department of Neurology, University Medical Center Ljubljana, Zaloška cesta 2, 1000 Ljubljana, Slovenia AD - Division of Medicine, Center for Rheumatology, University College London, 46 Cleveland Street, London W1T 4JF, United Kingdom AB - Postural tachycardia syndrome (PoTS) is a poorly understood but important cause of orthostatic intolerance resulting from cardiovascular autonomic dysfunction. PoTS is distinct from the syndromes of autonomic failure usually associated with orthostatic hypotension, such as pure autonomic failure and multiple system atrophy. Individuals affected by PoTS are mainly young (aged between 15 years and 40 years) and predominantly female. The symptoms - palpitations, dizziness and occasionally syncope - mainly occur when the patient is standing upright, and are often relieved by sitting or lying flat. Common stimuli in daily life, such as modest exertion, food ingestion and heat, are now recognized to be capable of exacerbating the symptoms. Onset of the syndrome can be linked to infection, trauma, surgery or stress. PoTS can be associated with various other disorders; in particular, joint hypermobility syndrome (also known as Ehlers - Danlos syndrome hypermobility type, formerly termed Ehlers - Danlos syndrome type III). This Review describes the characteristics and neuroepidemiology of PoTS, and outlines possible pathophysiological mechanisms of this syndrome, as well as current and investigational treatments. © 2011 Macmillan Publishers Limited. All rights reserved. N1 - Cited By :127 N1 - Export Date: 11 October 2019 M3 - Review DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84655167973&doi=10.1038%2fnrneurol.2011.187&partnerID=40&md5=7e5be6e5eb9e736f40aea159e2a678b9 ER - TY - JOUR TI - Atrioventricular node ablation and pacemaker implantation for recurrent syncope in a patient with postural tachycardia syndrome (POTS) T2 - Journal of Cardiovascular Electrophysiology VL - 22 IS - 11 SP - 1284 EP - 1287 PY - 2011 DO - 10.1111/j.1540-8167.2011.02078.x AU - Nakatani, Y. AU - Mizumaki, K. AU - Nishida, K. AU - Inoue, H. AD - Second Department of Internal Medicine, Graduate School of Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan AB - Ablate and Pace for POTS. A 42-year-old woman with postural tachycardia syndrome (POTS) was admitted to our hospital with severe palpitations, light-headedness, and syncope. Several drugs had been administered previously, but all had been discontinued due to intolerable adverse effects or limited efficacy. One of the drugs, the I f current inhibitor ivabradine, effectively slowed the patient's heart rate and relieved the symptoms, but was discontinued due to allergy. After unsuccessful sinus node ablation, atrioventricular node ablation and dual chamber pacemaker implantation was performed, which dramatically improved her symptoms and eliminated syncope. Atrioventricular node ablation could modify the cardiac autonomic balance and thereby suppressed the excessive orthostatic sympathetic activity. © 2011 Wiley Periodicals, Inc. KW - atrioventricular node ablation KW - autonomic nervous system KW - ivabradine KW - pacemaker KW - postural tachycardia syndrome N1 - Cited By :4 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-80755138427&doi=10.1111%2fj.1540-8167.2011.02078.x&partnerID=40&md5=7e8ba2a869751cb3beedfd9ac82a2d3b ER - TY - JOUR TI - Neurocardiogenic syncope coexisting with postural orthostatic tachycardia syndrome in patients suffering from orthostatic intolerance: A combined form of autonomic dysfunction T2 - PACE - Pacing and Clinical Electrophysiology VL - 34 IS - 5 SP - 549 EP - 554 PY - 2011 DO - 10.1111/j.1540-8159.2010.02994.x AU - Kanjwal, K. AU - Sheikh, M. AU - Karabin, B. AU - Kanjwal, Y. AU - Grubb, B.P. AD - Division of Cardiology, Department of Medicine, University of Toledo Medical Center, Mail Stop 1118, 3000 Arlington avenue, Toledo, OH 43614, United States AD - Division of Internal Medicine, Department of Medicine, University of Toledo Medical Center, Toledo, OH, United States AB - Introduction: There is anecdotal evidence that one or more forms of orthostatic intolerance (OI) subgroups may coexist in the same patients. However, there is a paucity of published data on the clinical features and management of patients who suffer from coexisting features of postural tachycardia syndrome (POTS) and neurocardiogenic syncope (NCS). We herein present our experience of 18 patients who we found displayed evidence of coexisting NCS and POTS. Methods: We reviewed charts of 300 POTS patients seen at the University of Toledo Syncope and Autonomic Disorders Center from 2003 to 2010 and found 18 patients eligible for inclusion in this study. Patients were included in this study if they reported clinical symptoms consistent with both POTS and NCS and then demonstrated a typical POTS pattern (a rise in heart rate without change in blood pressure [BP]) on head up tilt table (HUTT) within the first 10 minutes of upright posture followed by a neurocardiogenic pattern (a sudden fall in heart rate and/or fall in blood pressure) reproducing symptoms that were similar to the patients spontaneous episodes. Results: We found 18 patients, mean age (30 ± 12), with 15 (84%) women and three (16%) men, who met the inclusion criterion for this study. Each of these 18 patients demonstrated a typical POTS pattern within the first 10 minutes on initial physical exam and on a HUTT. Continued tilting beyond 10 minutes resulted in a sudden decline in heart rate (which in some patients manifested as an asystole that lasted anywhere between 10 and 32 seconds [mean of 18 seconds]) and/or a fall in BP in each of these patients demonstrating a pattern consistent with neurocardiogenic subtype of OI. The mean time to the NCS pattern of a fall in BP and heart was 15 minutes with a range of 13-20 minutes. This group of patients was highly symptomatic and reported frequent clinical symptoms that were suggestive of OI. Recurrent presyncope, syncope, orthostatic palpitations, exercise intolerance, and fatigue were the principal symptoms reported. Conclusion: NCS may coexist with POTS in a subgroup of patients suffering from OI. ©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc. KW - Neurocardiogenic syncope KW - Orthostatic intolerance KW - Postural tachycardia syndrome N1 - Cited By :17 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-79957564679&doi=10.1111%2fj.1540-8159.2010.02994.x&partnerID=40&md5=8ccce3c99d3bf5af66eee74a85e6aada ER - TY - JOUR TI - Orthostatic heart rate responses after prolonged space flights T2 - Clinical Autonomic Research VL - 21 IS - 2 SP - 121 EP - 124 PY - 2011 DO - 10.1007/s10286-010-0106-2 AU - Tank, J. AU - Baevsky, R.M. AU - Funtova, I.I. AU - Diedrich, A. AU - Slepchenkova, I.N. AU - Jordan, J. AD - Institute of Clinical Pharmacology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany AD - Institute of Biomedical Problems, Moscow, Russian Federation AD - Division of Clinical Pharmacology, Autonomic Dysfunction Center, Vanderbilt University, Nashville, TN, United States AB - Orthostatic tachycardia (POTS) can occur after space flights. We determined orthostatic heart rate responses in 18 cosmonauts before and 3-5 days after long-term space missions. Cosmonauts undergoing a cardiovascular training program in space experienced only moderate POTS after their return to earth. Cardiovascular countermeasures may have attenuated POTS. Another possible interpretation is that cardiovascular deconditioning is not sufficient to elicit full blown POTS in the absence of additional genetic or environmental factors. © Springer-Verlag 2011. KW - Cardiovascular deconditioning KW - Orthostatic tachycardia KW - Space flight N1 - Cited By :14 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-79958772916&doi=10.1007%2fs10286-010-0106-2&partnerID=40&md5=11a39f5448714766ec9aa609b680b650 ER - TY - JOUR TI - Effects of exercise training on arterial-cardiac baroreflex function in POTS T2 - Clinical Autonomic Research VL - 21 IS - 2 SP - 73 EP - 80 PY - 2011 DO - 10.1007/s10286-010-0091-5 AU - Galbreath, M.M. AU - Shibata, S. AU - VanGundy, T.B. AU - Okazaki, K. AU - Fu, Q. AU - Levine, B.D. AD - Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, 7232 Greenville Avenue, Dallas, TX 75231, United States AD - University of Texas, Southwestern Medical Center at Dallas, Dallas, TX, United States AB - Purpose Postural orthostatic tachycardia syndrome (POTS) is characterized by excessive tachycardia in the upright position. To test the hypothesis that patients with POTS have impaired arterial-cardiac baroreflex function, while exercise training normalizes the baroreflex function in these patients. Methods Seventeen POTS patients aged 27 ± 9 (mean ± SD) years underwent an exercise training program for 3 months. Arterial-cardiac baroreflex function was assessed by spectral and transfer function analysis of beat-tobeat R-R interval (RRI) and systolic blood pressure (SBP) variability in the supine position and at 60° upright tilt during spontaneous breathing before and after training. Data were compared with 17 healthy sedentary controls. Results Even though upright heart rate (HR) was greater in patients than controls, indexes of RRI variability did not differ between groups. Transfer function gain (SBP toRRI), used as an index of arterial-cardiac baroreflex sensitivity was similar between patients and controls in bothlow- (LF, P = 0.470) and high-frequency (HF, P = 0.663) ranges. Short-term exercise training decreased upright HR and increased RRI variability in POTS patients. LF baroreflex gain increased significantly in the supine position and during upright tilt [analysis of variance (ANOVA), P = 0.04 for training], while HF gain increased modestly after training (ANOVA, P = 0.105 for training) in these patients; however, the baroreflex gains remained within the normal ranges when compared with healthy controls. Conclusions These data suggest that patients with POTS have normal arterial-cardiac baroreflex function in both supine and upright postures. Short-term exercise training increases the baroreflex sensitivity in these patients, associated with a decrease in upright heart rate. © Springer-Verlag 2011. KW - Arterial pressure KW - Baroreflex function KW - Orthostatic intolerance N1 - Cited By :23 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-79958770047&doi=10.1007%2fs10286-010-0091-5&partnerID=40&md5=f8ba579e11c499038405ac281467638b ER - TY - JOUR TI - Cardiac repolarization variability in patients with postural tachycardia syndrome during graded head-up tilt T2 - Clinical Neurophysiology VL - 122 IS - 2 SP - 405 EP - 409 PY - 2011 DO - 10.1016/j.clinph.2010.06.017 AU - Baumert, M. AU - Lambert, E. AU - Vaddadi, G. AU - Sari, C.I. AU - Esler, M. AU - Lambert, G. AU - Sanders, P. AU - Nalivaiko, E. AD - Cardiovascular Research Centre, School of Medicine, School of Paediatrics and Reproductive Health, University of Adelaide, Australia AD - Human Neurotransmitter Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Australia AD - School of Biomedical Sciences, University of Newcastle, Australia AB - Objective: The aim of this study was to assess cardiac ventricular repolarization in patients with postural tachycardia syndrome (POTS) and further the possible link between ventricular repolarization and sympathetic nervous system activity. Methods: We recorded body surface ECGs together with plasma noradrenaline (NE) spillover, and muscle sympathetic nerve activity (MSNA) in twelve healthy control subjects (CON; 5 males; age: 23 ± 2 yrs) and 13 subjects with postural tachycardia syndrome (POTS; 4 males; 32 ± 13 yrs) during graded head-up tilt (0°-20°-30°-40°). Ventricular repolarization was assessed by computing various measures of beat-to-beat QT interval variability and T wave amplitude. Results: In patients with POTS, baseline heart rates were higher and MSNA increases during tilt were more pronounced than in CON. None of the QT variability measures was significantly affected by tilt or different between CON and POTS when corrected for heart rate. Contrary, the T wave amplitude flattened due to tilt (p<0.001) and this effect was significantly more pronounced in POTS (32% at 40°) than in CON (21% at 40°; p=0.03). Conclusions: Beat-to-beat variability of the QT interval is normal in patients with POTS. However, significantly more attenuated T waves during head-up tilt together with elevated MSNA levels suggest increased sympathetic outflow to the ventricular myocardium in patients with POTS. Significance: Monitoring of the T wave during tilt test may provide a non-invasive tool for assessing excessive sympathetic outflow to the ventricular myocardium. © 2010 International Federation of Clinical Neurophysiology. KW - Cardiac repolarization KW - Postural tachycardia syndrome KW - QT variability KW - Sympathetic nervous system N1 - Cited By :12 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650985864&doi=10.1016%2fj.clinph.2010.06.017&partnerID=40&md5=2943d37c19a3525289d8ad952e592504 ER - TY - JOUR TI - Cardiac Origins of the Postural Orthostatic Tachycardia Syndrome T2 - Journal of the American College of Cardiology VL - 55 IS - 25 SP - 2858 EP - 2868 PY - 2010 DO - 10.1016/j.jacc.2010.02.043 AU - Fu, Q. AU - VanGundy, T.B. AU - Galbreath, M.M. AU - Shibata, S. AU - Jain, M. AU - Hastings, J.L. AU - Bhella, P.S. AU - Levine, B.D. AD - Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, United States AD - The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, United States AB - Objectives: The purpose of this study was to test the hypothesis that a small heart coupled with reduced blood volume contributes to the postural orthostatic tachycardia syndrome (POTS) and that exercise training improves this syndrome. Background: Patients with POTS have marked increases in heart rate during orthostasis. However, the underlying mechanisms are unknown and the effective therapy is uncertain. Methods: Twenty-seven POTS patients underwent autonomic function tests, cardiac magnetic resonance imaging, and blood volume measurements. Twenty-five of them participated in a 3-month specially designed exercise training program with 19 completing the program; these patients were re-evaluated after training. Results were compared with those of 16 healthy controls. Results: Upright heart rate and total peripheral resistance were greater, whereas stroke volume and cardiac output were smaller in patients than in controls. Baroreflex function was similar between groups. Left ventricular mass (median [25th, 75th percentiles], 1.26 g/kg [1.12, 1.37 g/kg] vs. 1.45 g/kg [1.34, 1.57 g/kg]; p < 0.01) and blood volume (60 ml/kg [54, 64 ml/kg] vs. 71 ml/kg [65, 78 ml/kg]; p < 0.01) were smaller in patients than in controls. Exercise training increased left ventricular mass and blood volume by approximately 12% and approximately 7% and decreased upright heart rate by 9 beats/min [1, 17 beats/min]. Ten of 19 patients no longer met POTS criteria after training, whereas patient quality of life assessed by the 36-item Short-Form Health Survey was improved in all patients after training. Conclusions: Autonomic function was intact in POTS patients. The marked tachycardia during orthostasis was attributable to a small heart coupled with reduced blood volume. Exercise training improved or even cured this syndrome in most patients. It seems reasonable to offer POTS a new name based on its underlying pathophysiology, the "Grinch syndrome," because in this famous children's book by Dr. Seuss, the main character had a heart that was "two sizes too small.". © 2010 American College of Cardiology Foundation. KW - arterial pressure KW - autonomic control KW - endurance training KW - orthostatic tolerance KW - vasomotor sympathetic activity N1 - Cited By :131 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-77953318021&doi=10.1016%2fj.jacc.2010.02.043&partnerID=40&md5=2d4c2c07ed245e43dca81ae8bafe41ed ER - TY - JOUR TI - Successful use of ivabradine in a case of exaggerated autonomic dysfunction T2 - Turk Kardiyoloji Dernegi Arsivi VL - 38 IS - 4 SP - 285 EP - 289 PY - 2010 AU - Aliyev, F. AU - Çeliker, C. AU - Türkoǧlu, C. AU - Uzunhasan, I. AB - We present a 30-year-old male with complex and predominantly cardiovascular autonomic dysfunction. He had frequent syncopal attacks and paroxysmal atrial fibrillation (PAF). Physical, electrocardiographic, and echocardiographic findings were unremarkable. Syncopal attacks were precipitated by emotional stress, upright position, and micturition. Electrocardiograms obtained immediately after syncopal events revealed PAF with a low ventricular rate, which spontaneously returned to sinus rhythm without any medication. Syncopal events were suggestive of postural orthostatic tachycardia syndrome (POTS), were induced during upright position, and were associated with a sudden increase in heart rate to approximately 140 beats per minute and a sudden drop in blood pressure. Syncope was also induced during carotid sinus massage (CSM) in the upright position. It was thought that cardiac autonomic dysfunction, with POTS as the main component, was responsible for this clinical condition. Syncopal episodes increased in frequency during treatment with metoprolol. Treatment with ivabradine (5 mg twice a day) resulted in disappearance of syncopal episodes both during upright position and CSM. During six months of follow-up, the patient remained asymptomatic without syncope or atrial fibrillation. KW - Atrial fibrillation KW - Autonomic nervous system diseases KW - Benzazepines KW - Postural orthostatic tachycardia syndrome/complications KW - Syncope/etiology N1 - Cited By :10 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-79751525227&partnerID=40&md5=9972cfd840c53623167427c135a39d91 ER - TY - JOUR TI - Decreased upright cerebral blood flow and cerebral autoregulation in normocapnic postural tachycardia syndrome T2 - American Journal of Physiology - Heart and Circulatory Physiology VL - 297 IS - 2 SP - H664 EP - H673 PY - 2009 DO - 10.1152/ajpheart.00138.2009 AU - Ocon, A.J. AU - Medow, M.S. AU - Taneja, I. AU - Clarke, D. AU - Stewart, J.M. AD - Department of Physiology, Center for Hypotension, New York Medical College, Valhalla, NY, United States AD - Department of Pediatrics, Center for Hypotension, New York Medical College, Valhalla, NY, United States AD - Department of Medicine, Center for Hypotension, New York Medical College, Valhalla, NY, United States AD - Center for Hypotension, New York Medical College, 19 Bradhurst Ave., Hawthorne, NY 10532, United States AB - Postural tachycardia syndrome (POTS), a chronic form of orthostatic intolerance, has signs and symptoms of lightheadedness, loss of vision, headache, fatigue, and neurocognitive deficits consistent with reductions in cerebrovascular perfusion. We hypothesized that young, normocapnic POTS patients exhibit abnormal cerebral autoregulation (CA) that results in decreased static and dynamic cerebral blood flow (CBF) autoregulation. All subjects had continuous recordings of mean arterial pressure (MAP) and CBF velocity (CBFV) using transcranial Doppler sonography in both the supine supine position and during a 70° head-up tilt. During tilt, POTS patients (n = 9) demonstrated a higher heart rate than controls (n = 7) (109 ± 6 vs. 80 ± 2 beats/min, P < 0.05), whereas controls demonstrated a higher MAP than POTS (87 ± 2 vs. 77 ± 3 mmHg, P < 0.05). Also during tilt, mean CBFV decreased 19.5 ± 2.6% in POTS patients versus 10.3 ± 2.0% in controls (P < 0.05). We then used a transfer function analysis of MAP and CFBV in the frequency domain to quantify these changes. The low-frequency (LF; 0.04-0.15 Hz) component of CBFV variability increased during tilt in POTS patients (supine: 3 ± 0.9 vs. tilt: 9 ± 2, P < 0.02). In POTS patients, there was an increase in LF and high-frequency coherence between MAP and CBFV, an increase in LF gain, and a lack of significant change in phase. Static CA may be less effective in POTS patients compared with controls, since immediately after tilt CBFV decreased more in POTS patients and was highly oscillatory and autoregulation did not restore CBFV to baseline values until the subjects became supine. Dynamic CA may be less effective in POTS patients because MAP and CBFV during tilt became almost perfectly synchronous. We conclude that dynamic and static autoregulation of CBF are less effective in POTS patients compared with control subjects during orthostatic challenge. Copyright © 2009 the American Physiological Society. KW - Chronic orthostasis KW - Coherence KW - Transcranial Doppler N1 - Cited By :58 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-68049115749&doi=10.1152%2fajpheart.00138.2009&partnerID=40&md5=920e17f922d2da6f7220edd7b253e006 ER - TY - JOUR TI - Involvement of autonomic disorders T2 - Equilibrium Research VL - 67 IS - 3 SP - 234 EP - 241 PY - 2008 DO - 10.3757/jser.67.234 AU - Aoki, M. AD - Department of Otolaryngology, Gifu University Graduate School of Medicine AB - Patients with orthostatic dysregulation (OD)-associated disease may show autonomic disorders more frequently as compared with patients with other types of dizziness. However, the pathological mechanisms of OD remain unclear. We examined the cardiovascular autonomic function in dizzy patients with postural orthostatic tachycardia syndrome (POTS) or chronic orthostatic intolerance (OI) in order to evaluate the contribution of the autonomic disorders to the occurrence of dizziness. Heart rate variability analysis during the Schellong test showed that patients with POTS have hypo-parasympathetic function and relative hyper-sympathetic function, and that some patients with OI also have hypoparasympathetic function. In our clinic, single therapy with a β 1-blocker (Atenolol) for patients with POTS or single therapy with an a- agonist for patients with OI relieved orthostatic symptoms in 60% of the patients with POTS and OI. Further clinical studies on OD-associated disease to evaluate methods for accurate diagnosis and appropriate combined physical and pharmacotherapy may improve the outcomes in patients with OD-associated disease. KW - Combined therapy KW - Orthostatic dysregulation KW - Orthostatic intolerance KW - Parasympathetic function KW - Postural orthostatic tachycardia syndrome N1 - Cited By :2 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-47549091731&doi=10.3757%2fjser.67.234&partnerID=40&md5=e7938ebed8b8a103662f70a92ccb9e2d ER - TY - JOUR TI - A matched case control study of orthostatic intolerance in children/adolescents with chronic fatigue syndrome T2 - Pediatric Research VL - 63 IS - 2 SP - 196 EP - 202 PY - 2008 DO - 10.1203/PDR.0b013e31815ed612 AU - Galland, B.C. AU - Jackson, P.M. AU - Sayers, R.M. AU - Taylor, B.J. AD - Department of Women's and Children's Health, University of Otago, Dunedin 9015, New Zealand AD - Department of Women's and Children's Health, University of Otago, P.O. Box 913, Dunedin 9015, New Zealand AB - This study aimed to define cardiovascular and heart rate variability (HRV) changes following head-up tilt (HUT) in children/adolescents with chronic fatigue syndrome (CFS) in comparison to age- and gender-matched controls. Twenty-six children/adolescents with CFS (11-19 y) and controls underwent 70-degree HUT for a maximum of 30 min, but returned to horizontal earlier at the participant's request with symptoms of orthostatic intolerance (OI) that included lightheadedness. Using electrocardiography and beat-beat finger blood pressure, a positive tilt was defined as OI with 1) neurally mediated hypotension (NMH); bradycardia (HR <75% of baseline), and hypotension [systolic pressure (SysP) drops >25 mm Hg)] or 2) postural orthostatic tachycardia syndrome (POTS); HR increase >30 bpm, or HR >120 bpm (with/without hypotension). Thirteen CFS and five controls exhibited OI generating a sensitivity and specificity for HUT of 50.0% and 80.8%, respectively. POTS without hypotension occurred in seven CFS subjects but no controls. POTS with hypotension and NMH occurred in both. Predominant sympathetic components to HRV on HUT were measured in CFS tilt-positive subjects. In conclusion, CFS subjects were more susceptible to OI than controls, the cardiovascular response predominantly manifest as POTS without hypotension, a response unique to CFS suggesting further investigation is warranted with respect to the pathophysiologic mechanisms involved. © International Pediatrics Research Foundation, Inc. 2008. All Rights Reserved. N1 - Cited By :24 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-38349126010&doi=10.1203%2fPDR.0b013e31815ed612&partnerID=40&md5=4f93b8693f3ac2f6cbe802299d03662d ER - TY - JOUR TI - Sympathovagal balance analysis in idiopathic postural orthostatic tachycardia syndrome T2 - Acta Biomedica de l'Ateneo Parmense VL - 78 IS - 2 SP - 133 EP - 138+151 PY - 2007 AU - Russo, V. AU - De Crescenzo, I. AU - Ammendola, E. AU - Santangelo, L. AU - Calabrò, R. AD - Department of Cardiology, Second University of Naples, Monaldi Hospital, Naples, Italy AD - Department of Cardiology, Second University of Naples, Monaldi Hospital, V. L. Bianchi, 41, 80100 Naples, Italy AB - The idiopathic postural tachycardia syndrome (POTS) is a complex disorder characterized by chronic orthostatic symptoms and an increase in heart rate within 10 minutes of standing on upright posture, without significant orthostatic hypotension. We describe a case of a 36 year-old patient with POTS, diagnosed by head-up tilt testing. Power spectral analysis of heart rate variability (HRV), performed during the tilt test, revealed the ratio of low and high frequency powers (LF/HF) that increased with the onset of orthostatic intolerance. The increase in LF/HF power ratio may represent sympathetic beta-receptors hyperactivity. Atenolol alleviated his clinical symptoms. © Mattioli 1885. KW - Head up tilt test KW - Heart rate variability (HRV) KW - Postural orthostatic tachycardia sindrome (POTS) KW - Sympathovagal balance N1 - Cited By :7 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-36249015532&partnerID=40&md5=4df7296e50a54dd220c0b30f1e80482b ER - TY - JOUR TI - Reduced central blood volume and cardiac output and increased vascular resistance during static handgrip exercise in postural tachycardia syndrome T2 - American Journal of Physiology - Heart and Circulatory Physiology VL - 293 IS - 3 SP - H1908 EP - H1917 PY - 2007 DO - 10.1152/ajpheart.00439.2007 AU - Stewart, J.M. AU - Taneja, I. AU - Medow, M.S. AD - Department of Pediatrics, New York Medical College, Valhalla, NY, United States AD - Department of Physiology, New York Medical College, Valhalla, NY, United States AD - Department of Medicine, New York Medical College, Valhalla, NY, United States AD - Research Division, Hypotension Laboratory, New York Medical College, 19 Bradhurst Ave., Hawthorne, NY 10532, United States AB - Postural tachycardia syndrome (POTS) is characterized by exercise intolerance and sympathoactivation. To examine whether abnormal cardiac output and central blood volume changes occur during exercise in POTS, we studied 29 patients with POTS (17-29 yr) and 12 healthy subjects (18-27 yr) using impedance and venous occlusion plethysmography to assess regional blood volumes and flows during supine static handgrip to evoke the exercise pressor reflex. POTS was subgrouped into normal and low-flow groups based on calf blood flow. We examined autonomic effects with variability techniques. During handgrip, systolic blood pressure increased from 112 ± 4 to 139 ± 9 mmHg in control, from 119 ± 6 to 143 ± 9 in normal-flow POTS, but only from 117 ± 4 to 128 ± 6 in low-flow POTS. Heart rate increased from 63 ± 6 to 82 ± 4 beats/min in control, 76 ± 3 to 92 ± 6 beats/min in normal-flow POTS, and 88 ± 4 to 100 ± 6 beats/min in low-flow POTS. Heart rate variability and coherence markedly decreased in low-flow POTS, indicating uncoupling of baroreflex heart rate regulation. The increase in central blood volume with handgrip was absent in low-flow POTS and blunted in normal-flow POTS associated with abnormal splanchnic emptying. Cardiac output increased in control, was unchanged in low-flow POTS, and was attenuated in normal-flow POTS. Total peripheral resistance was increased compared with control in all POTS. The exercise pressor reflex was attenuated in low-flow POTS. While increased cardiac output and central blood volume characterizes controls, increased peripheral resistance with blunted or eliminated in central blood volume increments characterizes POTS and may contribute to exercise intolerance. Copyright © 2007 the American Physiological Society. KW - Exercise intolerance KW - Mechanoreflex KW - Metaboreflex KW - Orthostatic intolerance KW - Regional blood volume N1 - Cited By :10 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-34548444628&doi=10.1152%2fajpheart.00439.2007&partnerID=40&md5=329ec8be0cf2eec5a84ec98c75ed01b2 ER - TY - JOUR TI - Postural orthostatic tachycardia syndrome: An underrecognized disorder T2 - Internal Medicine Journal VL - 37 IS - 8 SP - 529 EP - 535 PY - 2007 DO - 10.1111/j.1445-5994.2007.01356.x AU - Pandian, J.D. AU - Dalton, K. AU - Henderson, R.D. AU - McCombe, P.A. AD - Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia AD - Department of Neurology, Royal Brisbane and Women's Hospital, Herston Road, Herston, QLD 4029, Australia AB - Background: Postural orthostatic tachycardia syndrome (POTS), a clinical syndrome of orthostatic intolerance characterized by excessive tachycardia and symptoms of cerebral hypoperfusion on standing, is not well recognized in Australia. The aim was to study the clinical symptomatology, results of autonomic testing and outcome in patients with POTS. Methods: Sixteen subjects from a tertiary referral centre who met the criteria for POTS were studied between January 2003 and January 2006. Ten of these patients consented to be interviewed using a validated autonomic symptom questionnaire. Heart rate responses to deep breathing and the Valsalva manoeuvre were measured using Colin BP-508 machine (WR Medical Electronic Co., Stillwater, MN, USA). Tilt studies were carried out for 10 min to 80°of head-up tilting. Patient outcome was assessed as functionally normal, able to stand 30 min without symptoms, able to work and carry out recreational activities or worse on follow up. Results: The mean age of 10 subjects was 24.9 ± 6.8 years, six being women. The mean duration of symptoms was 70.7 months (range 3-228 months). The common presenting orthostatic symptoms were light-headedness (100%), palpitations (90%), pallor (90%), weakness (80%) and clammy skin (80%). The mean heart rate increment during the tilt study was 51.7 ± 14.3 b.p.m. The mean duration of follow up was 8.9 months (range 1-16 months). Only five patients were functioning normally at the follow-up visit. Conclusion: POTS is an underrecognized but persistent autonomic disorder in young patients with a variety of symptoms and variable outcome. © 2007 Royal Australasian College of Physicians. KW - Postural orthostatic tachycardia syndrome N1 - Cited By :7 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-34447515853&doi=10.1111%2fj.1445-5994.2007.01356.x&partnerID=40&md5=99d79f2ff2fb368a298e66f53cd70edf ER - TY - JOUR TI - Relations between psychometric profiles and cardiovascular autonomic regulation in physical education students T2 - European Journal of Applied Physiology VL - 99 IS - 6 SP - 615 EP - 622 PY - 2007 DO - 10.1007/s00421-006-0385-4 AU - Nuissier, F. AU - Chapelot, D. AU - Vallet, C. AU - Pichon, A. AD - Laboratoire des Réponses Cellulaires et Fonctionnelles á l'Hypoxie, UFR SMBH, Université Paris 13, 74 rue Marcel Cachin, 93017 Bobigny Cedex, France AB - This study was designed to investigate physical education (PE) students the link between mood disturbances, caused by psychological or physical stressors associated with studying, and the autonomic nervous system modifications. PE students completed the profile of mood state (POMS) questionnaire at the end of the university year. Heart rate variability (HRV) was then measured during a head-up tilt test (HUT) in those with the highest and lowest total mood disturbance (TMD) scores on three successive POMS. Among the 218 students who completed the POMS (85 female and 137 male), 65 had high TMD scores, suggesting mood disturbances and fatigue. The final sample included 12 subjects in the potentially overtrained (POT) group and 16 subjects in the control (CTL) group. A greater decrease of two indices of the autonomic system (SD1 and RMSSD) was observed during the HUT in the POT than in the CTL group (P < 0.05). The depression (Dep) and vigor (Vig) subscales of POMS were correlated with several HRV indices. More specifically, in the POT group, the Vig score was correlated with autonomous activity in the supine position, and the Dep score with percentages of change of sympatho-vagal activity during the HUT. This suggests that (1) POT students could present a weaker autonomic response to HUT, (2) Dep and Vig subscales of the POMS questionnaire may indicate autonomic dysregulations. © Springer-Verlag 2007. KW - Autonomic nervous system KW - Fatigue KW - Heart rate variability KW - Overtraining KW - POMS N1 - Cited By :14 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-33947153955&doi=10.1007%2fs00421-006-0385-4&partnerID=40&md5=0eb34fb71d0725132c06263350c64ab9 ER - TY - JOUR TI - Tilt table testing in childhood: Improved sensitivity by non-invasive haemodynamic monitoring devices? T2 - Acta Cardiologica VL - 61 IS - 6 SP - 615 EP - 621 PY - 2006 DO - 10.2143/AC.61.6.2017960 AU - Dalla Pozza, R. AU - Kleinmann, A. AU - Kozlik-Feldmann, R. AU - Netz, H. AD - Department of Paediatric Cardiology, Ludwig-Maximilians-University, Munich, Germany AD - Marchioninistr. 15, D-81377 Munich, Germany AB - Objective - Tilt table testing represents a valuable diagnostic method in suspected neurally mediated syncope. As sympathovagal imbalance and impaired baroreceptor sensitivity (BRS) have been observed in these patients, both methods were used in this study to investigate whether a combination of these parameters would improve sensitivity and whether specific patterns of neurally mediated syncopes would correspond to characteristic trends in heart rate variability (HRV) and BRS. Methods and results - Fifty-one pts. (29 female, mean age 14.5 ± 3.9 y) with unexplained syncope and 15 control subjects (9 female, mean age 14.8 ± 3.0 y) were tested following a standard tilt table test protocol. Power spectral analysis (PSA) of HRV and BRS calculation were used additionally to beat-to-beat blood pressure and ECG-monitoring. Twenty-three out of 51 pts. (45%) experienced a syncope after 18 ± 10.2 min of tilting. In 2/23 patients (8.6%) a postural tachycardia syndrome (POTS), in 14/23 (60.8%) a neurally mediated syncope of mixed type, in 2/23 (8.6%) a vasodepressor syncope and in 5/23 (21.7%) a cardioinhibitory syncope with asystole were observed. PSA of HRV and BRS revealed a specificity, sensitivity, and positive and negative predictive values of the cut-off points in combination (LF/HF ≥ 2.7 and BRS ≤ 8) of 93.3%, 65.2%, 93% and 39%, respectively. Conclusion - In this study population, BRS and PSA of HRV were able to improve sensitivity of tilt testing after unexplained syncope. Specific BRS or HRV patterns in different mechanisms of neurally mediated syncope could not be identified possibly due to the small sample size. KW - Baroreceptor function KW - Heart rate variability KW - Neurally mediated syncope KW - Tilt table testing N1 - Cited By :3 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845797066&doi=10.2143%2fAC.61.6.2017960&partnerID=40&md5=d2d3da789a41d3eef2f62e83187576a6 ER - TY - JOUR TI - Seed germination and seedling growth of diferentes progenies of Euterpe edulis Mart ST - Germinação de sementes e crescimento de plântulas de diferentes progênies de Euterpe edulis Mart T2 - Revista Arvore VL - 30 IS - 5 SP - 693 EP - 699 PY - 2006 DO - 10.1590/S0100-67622006000500002 AU - Martins-Corder, M.P. AU - Saldanha, C.W. AD - Departamento de Ciências Florestais, Universidade Federal de Santa Maria (UFSM), Santa Maria-RS, Brazil AD - Programa de Pós-Graduação em Geomática, Universidade Federal de Santa Maria, Brazil AB - Heart-of-palm tree (Euterpe edulis Mart.) is a native species from Atlantic Forest, known by its production of palm heart. It is a palm with high potential to sustainable management and the fauna largely consumes its fruits. Heart-of-palm propagation through seeds is a determinant factor in the production of quality seedlings to the maintenance of sustainable populations. The objective of this study, conducted at Forest Biotechnology Laboratory from the Federal University of Santa Maria, was to evaluate the germination and initial growth of 15 progenies of heart-of-palm tree. The experimental design was completely randomized, with four replications and 15 treatments (progenies) distributed in 10 liner pots, with two seeds in each one. The following characteristics were analyzed: seed germination percentage, seedling survival percentage, stem diameter, leaf number and plant height. The results showed that heart-of-palm tree progenies had higher variability for survival percentage (ranging from 26 to 58% and average of 38%), at 210 days. The most vigorous seedlings derived from provenance P12, which showed better results for survival percentage (x-=58%), height (x-= 2.12 cm), leaf number (x-= 1.45) and stem diameter (x- = 0.7 cm). The provenances with low survival rates (x-= 26%) had more delayed seed germination and consequently showed lower seedling height (x-= 1.7 cm). Hence, batches of seeds derived from the studied population of E. edulis should be formed by the provenances showing homogeneity among the analyzed characteristics, in order to facilitate seedling management in nursery conditions, and also, guarantee a higher uniformity of the material to be established in field conditions. KW - Genetic improvement and survival KW - Heart-of-palm tree N1 - Cited By :13 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-33846496048&doi=10.1590%2fS0100-67622006000500002&partnerID=40&md5=ae4ec0d256279f96d3689467450a1311 ER - TY - JOUR TI - Postural hypocapnic hyperventilation is associated with enhanced peripheral vasoconstriction in postural tachycardia syndrome with normal supine blood flow T2 - American Journal of Physiology - Heart and Circulatory Physiology VL - 291 IS - 2 SP - H904 EP - H913 PY - 2006 DO - 10.1152/ajpheart.01359.2005 AU - Stewart, J.M. AU - Medow, M.S. AU - Cherniack, N.S. AU - Natelson, B.H. AD - Department of Pediatrics, New York Medical College, Valhalla, NY, United States AD - Department of Physiology, New York Medical College, Valhalla, NY, United States AD - Department of Medicine, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ, United States AD - Department of Neurosciences, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ, United States AD - Depts. of Pediatrics and Physiology, Research Division and Hypotension Laboratory, New York Medical College, 19 Bradhurst Ave., Hawthorne, NY 10532, United States AB - Previous investigations have demonstrated a subset of postural tachycardia syndrome (POTS) patients characterized by normal peripheral resistance and blood volume while supine but thoracic hypovolemia and splanchnic blood pooling while upright secondary to splanchnic hyperemia. Such "normal-flow" POTS patients often demonstrate hypocapnia during orthostatic stress. We studied 20 POTS patients (14-23 yr of age) and compared them with 10 comparably aged healthy volunteers. We measured changes in heart rate, blood pressure, heart rate and blood pressure variability, arm and leg strain-gauge occlusion plethysmography, respiratory impedance plethysmography calibrated against pneumotachography, end-tidal partial pressure of carbon dioxide (PET CO2), and impedance plethysmographic indexes of blood volume and blood flow within the thoracic, splanchnic, pelvic (upper leg), and lower leg regional circulations while supine and during upright tilt to 70°. Ten POTS patients demonstrated significant hyperventilation and hypocapnia (POTS HC) while 10 were normocapnic with minimal increase in postural ventilation, comparable to control. While relative splanchnic hypervolemia and hyperemia occurred in both POTS groups compared with controls, marked enhancement in peripheral vasoconstriction occurred only in POTSHC and was related to thoracic blood flow. Variability indexes suggested enhanced sympathetic activation in POTSHC compared with other subjects. The data suggest enhanced cardiac and peripheral sympathetic excitation in POTS HC. Copyright © 2006 the American Physiological Society. KW - Hypocapnia KW - Orthostatic intolerance KW - Vasoconstriction N1 - Cited By :32 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-33746808099&doi=10.1152%2fajpheart.01359.2005&partnerID=40&md5=818821a59a7f39a64e5ef79b0bb4015b ER - TY - JOUR TI - Complex regional pain syndromes in children and adolescents: Regional and systemic signs and symptoms and hemodynamic response to tilt table testing T2 - Clinical Journal of Pain VL - 22 IS - 4 SP - 399 EP - 406 PY - 2006 DO - 10.1097/01.ajp.0000192514.50955.d6 AU - Meier, P.M. AU - Alexander, M.E. AU - Sethna, N.F. AU - De Jong-De Vos Van Steenwijk, C.C.E. AU - Zurakowski, D. AU - Berde, C.B. AD - Department of Anesthesia, University Medical Center Utrecht, Netherlands AD - Department of Cardiology, University Medical Center Utrecht, Netherlands AD - Academic Dept., General Pediatrics, University Medical Center Utrecht, Netherlands AD - Department of Orthopaedic Surgery, Children's Hospital, Harvard Medical School, Boston, MA, United States AD - Pain Treatment Service, Department of Anesthesiology, Perioperative and Pain Medicine, Children's Hospital, 333 Longwood Ave., Boston, MA 02115, United States AB - OBJECTIVE: Complex regional pain syndromes (CRPS) involve neuropathic limb pain and localized circulatory abnormalities. The authors hypothesized that (1) pediatric CRPS patients exhibit systemic autonomic symptoms and orthostatic and/or cardiac sympatho-vagal dysregulation and (2) their orthostatic regulation differs from healthy controls and pediatric patients with postural orthostatic tachycardia syndrome (POTS). METHODS: CRPS children and adolescents (n=20) underwent a 6-week trial of physical therapy and cognitive-behavioral treatment. Measures included pain and function scores, regional and systemic autonomic symptom profiles, heart rate and blood pressure with tilt, heart rate variability indices, and baroreflex gain. Systemic autonomic symptoms were recorded in 55 healthy pediatric controls. Tilt responses in CRPS patients were compared with those of 21 POTS patients and 39 healthy controls. RESULTS: CRPS patients' regional autonomic symptoms, pain, and limb function improved over 6 weeks (P<0.01). At baseline CRPS patients reported more systemic autonomic symptoms than controls (P<0.05). Tilt table test showed orthostatic stability, but the mean heart rate increase with tilt was greater in CRPS patients than controls (P<0.001). POTS patients showed significant increases with tilt in mean heart rate and diastolic and systolic blood pressures compared with controls (P<0.001). There were significant increases in the mean systolic and diastolic blood pressures in POTS compared with CRPS patients but no difference in the mean heart rate between groups. DISCUSSION: CRPS patients reported multiple regional and systemic autonomic symptoms that improved during the study course, and they experienced minimal and transient tilt table-induced hemodynamic changes compared with POTS patients but relatively similar to controls. Copyright © 2006 by Lippincott Williams & Wilkins. KW - Autonomic signs and symptoms KW - Complex regional pain syndrome KW - Neuropathic pain KW - Postural orthostatic tachycardia syndrome KW - Tilt table test N1 - Cited By :29 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-33745881926&doi=10.1097%2f01.ajp.0000192514.50955.d6&partnerID=40&md5=0f056b540687759865ce69df6c95b429 ER - TY - JOUR TI - Endothelial NO synthase polymorphisms and postural tachycardia syndrome T2 - Hypertension VL - 46 IS - 5 SP - 1103 EP - 1110 PY - 2005 DO - 10.1161/01.HYP.0000185462.08685.da AU - Garland, E.M. AU - Winker, R. AU - Williams, S.M. AU - Jiang, L. AU - Stanton, K. AU - Byrne, D.W. AU - Biaggioni, I. AU - Cascorbi, I. AU - Phillips III, J.A. AU - Harris, P.A. AU - Rüdiger, H. AU - Robertson, D. AD - Autonomic Dysfunction Center, Vanderbilt University, Nashville, TN, United States AD - Division of Cardiovascular Medicine, Vanderbilt University, Nashville, TN, United States AD - Center for Human Genetics Research, Vanderbilt University, Nashville, TN, United States AD - Division of Medical Genetics, Vanderbilt University, Nashville, TN, United States AD - Department of Biostatistics, Vanderbilt University, Nashville, TN, United States AD - Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States AD - Division of Occupational Medicine, Medical University of Vienna, Währinger Gürtel, Austria AD - Institute of Pharmacology, University Hospital Schleswig Holstein, Kiel, Germany AD - Autonomic Dysfunction Center, AA3228 Medical Center N, Vanderbilt University, Nashville, TN 37232-2195, United States AB - Postural tachycardia syndrome (POTS) is a heterogeneous disorder characterized by an excessive rise in heart rate and symptoms consistent with cerebral hypoperfusion in the upright position. NO produced by endothelial NO synthase is a significant factor in the regulation of blood flow. Genetic polymorphisms in the promoter region (T-786C) and exon 7 (E298D) of the NO synthase isoform 3 gene affect enzyme activity and have been associated with a number of cardiovascular diseases. Because some findings in POTS suggest aberrant NO-mediated functions, we postulated that the variant genotypes of these polymorphisms may increase the risk of developing POTS and correlate with more severe symptoms. We genotyped 136 patients with POTS (mean age 32.2±9.9 years; 46 men and 90 women) from Nashville, Tenn, and Vienna, Austria, and compared them with 191 healthy volunteers (mean age 29.1±8.0 years; 127 men and 64 women). Participants also underwent orthostatic testing with blood pressure, heart rate, and plasma norepinephrine measurements while supine and upright. The frequencies of the -786CC and 298DD genotypes were significantly lower in patients with POTS than in control subjects (odds ratio [OR], 0.28; 95% confidence interval [CI], 0.14 to 0.57; P=0.001 for -786CC; and OR, 0.44; 95% CI, 0.21 to 0.91; P=0.033 for 298DD). According to 2-locus genotype analyses, patients with -786CC and 298EE or 298ED experienced the largest changes in heart rate and plasma norepinephrine with standing. These results indicate that NO may influence the development of POTS and the severity of POTS symptoms. © 2005 American Heart Association, Inc. KW - Genetics KW - Heart rate KW - Hemodynamics KW - Nitric oxide KW - Norepinephrine KW - Tachycardia N1 - Cited By :21 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-27444446110&doi=10.1161%2f01.HYP.0000185462.08685.da&partnerID=40&md5=abcc999b8828b68b01ec5a3b4f89f330 ER - TY - JOUR TI - Use of time-frequency analysis to investigate temporal patterns of cardiac autonomic response during head-up tilt in chronic fatigue syndrome T2 - Autonomic Neuroscience: Basic and Clinical VL - 113 IS - 1-2 SP - 55 EP - 62 PY - 2004 DO - 10.1016/j.autneu.2004.05.001 AU - Yoshiuchi, K. AU - Quigley, K.S. AU - Ohashi, K. AU - Yamamoto, Y. AU - Natelson, B.H. AD - Department of Neurosciences, Univ. Med. and Dent. of New Jersey, New Jersey Med. Sch., 88 Ross S., East Orange, NJ, United States AD - Department of Psychosomatic Medicine, Faculty of Medicine, The University of Tokyo, Japan AD - Department of Psychiatry, Univ. Med. and Dent. of New Jersey, New Jersey Medical School, 07018, East Orange, NJ, United States AD - Educational Physiology Laboratory, Graduate School of Education, The University of Tokyo, Japan AB - Although a number of studies have reported alterations in cardiac autonomic nervous system function in chronic fatigue syndrome (CFS), the results are not consistent across studies. Reasons for these discrepancies include (1) the use of a heterogeneous patient sample that included those with orthostatic postural tachycardia (POTS), a condition with an autonomic changes, and (2) the use of frequency domain techniques which require a stationary signal and averaging data across relatively long epochs. To deal with these shortcomings, we used the smoothed pseudo-Wigner-Ville transform (SPWVT) to analyze heart rate variability (HRV) and blood pressure variability (BPV) during head-up tilt (HUT) by separating CFS patients into those with and without POTS. SPWVT has the advantage of providing instantaneous information about autonomic function under nonstable physiological conditions. We studied 18 CFS patients without POTS, eight CFS patients with POTS and 25 sedentary healthy controls during supine rest and during the first 10 min after HUT. While we found significant effects of postural change in both groups for all autonomic variables, there were significant group×time interactions between CFS without POTS and controls for only instant center frequency (ICF) within the low frequency region both from HRV (p=0.02) and from BPV (p=0.01). Although the physiological meaning of ICF still remains unknown, the data suggest that even CFS patients without POTS may have a subtle underlying disturbance in autonomic function. © 2004 Elsevier B.V. All rights reserved. KW - Blood pressure variability KW - Chronic fatigue syndrome KW - Head-up tilt KW - Heart rate variability KW - Smoothed pseudo-Wigner-Ville transform KW - Time-frequency analysis N1 - Cited By :28 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-3543050049&doi=10.1016%2fj.autneu.2004.05.001&partnerID=40&md5=ebab09684a10934d3c281a9091b6aa6a ER - TY - JOUR TI - Heart rate-dependent electrocardiogram abnormalities in patients with postural tachycardia syndrome T2 - Autonomic Neuroscience: Basic and Clinical VL - 103 IS - 1-2 SP - 106 EP - 113 PY - 2003 DO - 10.1016/S1566-0702(02)00213-8 AU - Singer, W. AU - Shen, W.K. AU - Opfer-Gehrking, T.L. AU - McPhee, B.R. AU - Hilz, M.J. AU - Low, P.A. AD - Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States AD - Department of Cardiology, Mayo Clinic, Rochester, MN, United States AD - Department of Neurology, University of Erlangen, Nuremberg, Germany AB - We recently published data suggesting the presence of an intrinsic sinus node abnormality in a subgroup of patients with the postural tachycardia syndrome (POTS). Based on the hypothesis that more widespread abnormalities of cardiac electrophysiologic properties may be present in POTS, we undertook a study to compare cardiac conduction and repolarization at different heart rate levels in patients with POTS and healthy controls. Eleven healthy controls and fourteen patients with POTS participated in the study. Acquisition of 12-lead electrocardiogram recordings were made during supine rest and during gradual head-up tilt. The heart rate of controls was titrated by isoproterenol infusion to match the heart rate of patients. Indices for cardiac conduction (PR interval, QRS duration, and R wave axis) and repolarization (QT interval, QTc interval, and T wave axis) were then compared at different heart rate levels. The PR interval decreased with increasing heart rate in controls more than in patients, resulting in a significantly longer PR interval in patients at the fastest heart rate level. The QT and QTc intervals were significantly shorter in POTS over the entire analyzed heart rate range. The T wave axis decreased with increasing heart rate in patients only. This resulted in a significantly lower T wave axis in patients at the fastest heart rate level. Our data suggest abnormalities of atrioventricular conduction and ventricular repolarization in patients with POTS. These findings may reflect intrinsic cardiac electrophysiologic abnormalities or may be secondary due to abnormalities of cardiac autonomic innervation. © 2002 Elsevier Science B.V. All rights reserved. KW - Electrocardiography KW - Orthostatic intolerance KW - Pathophysiology KW - POTS N1 - Cited By :2 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-0037473844&doi=10.1016%2fS1566-0702%2802%2900213-8&partnerID=40&md5=0f6c64161779763e781de6ddaabaa32c ER - TY - JOUR TI - Clinical and physiological effects of an acute α-1 adrenergic agonist and a β-1 adrenergic antagonist in chronic orthostatic intolerance T2 - Circulation VL - 106 IS - 23 SP - 2946 EP - 2954 PY - 2002 DO - 10.1161/01.CIR.0000040999.00692.F3 AU - Stewart, J.M. AU - Munoz, J. AU - Weldon, A. AD - Department of Pediatrics, New York Medical College, Valhalla, NY 10595, United States AD - Department of Physiology, New York Medical College, Valhalla, NY 10595, United States AD - Department of Pediatrics, Munger Pavilion, New York Medical College, Valhalla, NY 10595, United States AB - Background - Adrenergic agents are commonly used in the treatment of chronic orthostatic intolerance with postural tachycardia syndrome (POTS), POTS may be associated with increased limb blood flow ("high flow") and defective orthostatic vasoconstriction or decreased limb blood flow ("low flow") and potentially with small blood volume. Methods and Results - We investigated the consequences of short-term intravenous administration of an α-1 adrenergic agonist, phenylephrine, and β-1 adrenergic antagonist, esmolol, in 14 patients with POTS aged 13 to 19 years. Indices of heart rate and blood pressure variability, peripheral blood flow, and arterial resistance were assessed, and the capacitance relation was computed for every subject using venous occlusion plethysmography. Patients were tilted to 35° upright while medicated and while unmedicated, and measurements were repeated. Phenylephrine improved orthostatic tolerance and normalized hemodynamics and indices of heart rate/blood pressure variability while supine and while upright, producing significant peripheral vasoconstriction and venoconstriction (20% capacitance change). Esmolol did not improve orthostatic tolerance or hemodynamics. A subgroup of low-flow POTS patients had exaggerated venoconstriction to phenylephrine (50% capacitance change) but others had no response. Conclusions - Phenylephrine, but not esmolol, improves orthostatic tolerance and hemodynamics in POTS. This lends support to the use of oral α-1 agonists in the treatment of patients with chronic orthostatic intolerance. KW - Blood flow KW - Heart rate KW - Vasoconstriction N1 - Cited By :44 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-0037016042&doi=10.1161%2f01.CIR.0000040999.00692.F3&partnerID=40&md5=2407930f2a5e2aec51f2261182a0eee5 ER - TY - JOUR TI - Reversible sympathetic vasomotor dysfunction in POTS patients T2 - Revista Portuguesa de Cardiologia VL - 19 IS - 11 SP - 1163 EP - 1170 PY - 2000 AU - Freitas, J. AU - Santos, R. AU - Azevedo, E. AU - Costa, O. AU - Carvalho, M. AU - Falcão de Freitas, A. AD - Centro de Estudos Funcao Autonomica, Hospital de São João, 4200 Porto, Portugal AB - Background: Orthostatic intolerance refers to the development upon assuming an upright posture of disabling symptoms, which are partly relieved by resuming the supine position. Postural tachycardia syndrome (POTS) is an orthostatic intolerance syndrome characterized by palpitations due to excessive orthostatic sinus tachycardia, lightheadedness, tremor, and near-syncope. Patients usually undergo extensive medical, cardiac, endocrine, neurological and psychiatric evaluation, which usually fails to identify a specific abnormality. We investigated the autonomic and hemodynamic profile of POTS patients and the efficacy of bisoprolol and or fludrocortisone. Methods and Results: We evaluated eleven female patients with POTS before and after medical treatment with a cardio-selective beta blocker (bisoprolol) and/or fludrocortisone, and eleven age-matched controls. Variability of heart rate and systolic blood pressure was assessed by Fast Fourier Transform, and spontaneous baroreceptor gain by temporal sequences slope and α index. Modelflow was used to quantify hemodynamics. All patients improved greatly after medication. The autonomic and hemodynamic impairment observed in patients with POTS, particularly after orthostatic stress, is treated effectively with bisoprolol and/or fludrocortisone. These results need further confirmation in a controlled double-blind study. Conclusions: Proper medical treatment dramatically improves the clinical and autonomic/hemodynamic disturbances observed in patients with POTS. The data support the hypothesis that POTS is due to a hyperadrenergic activation and/or hypovolemia during orthostasis. KW - Autonomic activity KW - Bisoprolol KW - Fludrocortisone KW - Non-invasive hemodynamics KW - Orthostatic intolerance KW - POTS N1 - Cited By :7 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034519042&partnerID=40&md5=a35db897be791c1b8f277d3225c6fa58 ER - TY - JOUR TI - Autonomic nervous system dysfunction in adolescents with postural orthostatic tachycardia syndrome and chronic fatigue syndrome is characterized by attenuated vagal baroreflex and potentiated sympathetic vasomotion T2 - Pediatric Research VL - 48 IS - 2 SP - 218 EP - 226 PY - 2000 DO - 10.1203/00006450-200008000-00016 AU - Stewart, J.M. AD - Department of Pediatrics, Center for Pediatric Hypotension, New York Medical College, Valhalla, NY 10595, United States AD - Center for Pediatric Hypotension, Division of Pediatric Cardiology, New York Medical College, Valhalla, NY 10595, United States AB - The objective was to determine the nature of autonomic and vasomotor changes in adolescent patients with orthostatic tachycardia associated with the chronic fatigue syndrome (CFS) and the postural orthostatic tachycardia syndrome (POTS). Continuous electrocardiography and arterial tonometry was used to investigate the heart rate and blood pressure responses before and 3-5 min after head-up tilt in 22 adolescents with POTS and 14 adolescents with CFS, compared with control subjects comprising 10 healthy adolescents and 20 patients with simple faint. Heart rate and blood pressure variability, determined baroreceptor function using transfer function analysis, and measured cardiac vagal and adrenergic autonomic responses were calculated using timed breathing and the quantitative Valsalva maneuver. Two of 10 healthy controls and 14 of 20 simple faint patients experienced vasovagal syncope during head-up tilt. By design, all CFS and POTS patients experienced orthostatic tachycardia, often associated with hypotension. R-R interval and heart rate variability were decreased in CFS and POTS patients compared with control subjects and remained decreased with head-up tilt. Low-frequency (0.05-0.15 Hz) blood pressure variability reflecting vasomotion was increased in CFS and POTS patients compared with control subjects and increased further with head-up tilt. This was associated with depressed baroreflex transfer indicating baroreceptor attenuation through defective vagal efferent response. Only the sympathetic response remained. Heart rate variability declined progressively from normal healthy control subjects through syncope to POTS to CFS patients. Timed breathing and Valsalva maneuver were most often normal in CFS and POTS patients, although abnormalities in select individuals were found. Heart rate and blood pressure regulation in POTS and CFS patients are similar and indicate attenuated efferent vagal baroreflex associated with increased vasomotor tone. Loss of beat-to-beat heart rate control may contribute to a destabilized blood pressure resulting in orthostatic intolerance. The dysautonomia of orthostatic intolerance in POTS and in chronic fatigue are similar. N1 - Cited By :145 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033943872&doi=10.1203%2f00006450-200008000-00016&partnerID=40&md5=bd1bf250037dcce938b7569a72e1e748 ER - TY - JOUR TI - Clinical improvement in patients with orthostatic intolerance after treatment with bisoprolol and fludrocortisone T2 - Clinical Autonomic Research VL - 10 IS - 5 SP - 293 EP - 299 PY - 2000 DO - 10.1007/BF02281112 AU - Freitas, J. AU - Santos, R. AU - Azevedo, E. AU - Costa, O. AU - Carvalho, M. AU - Falcão de Freitas, A. AD - Centro de Estudos Da Função Autonómica, Hospital de São João Do Porto, Porto 4200, Portugal AD - Faculdade de Medicina Do Porto, Porto, Portugal AB - Orthostatic intolerance is the development of disabling symptoms upon assuming an upright posture that axe relieved partially by resuming the supine position. Postural tachycardia syndrome (POTS) is an orthostatic intolerance syndrome characterized by palpitations because of excessive orthostatic sinus tachycardia, lightheadedness, tremor, and near-syncope. Patients usually undergo extensive medical, cardiac, endocrine, neurologic, and psychiatric evaluation, which usually fails to identify a specific abnormality. The authors investigated the autonomic and hemodynamic profile of patients with POTS and the effectiveness of bisoprolol and fludrocortisone. The authors evaluated 11 female patients with POTS before and after medical treatment with a cardioselective bisoprolol β-blocker or fludrocortisone, or both, and 11 age-matched control patients. Variability of heart rate and systolic blood pressure was assessed by fast Fourier transform, and spontaneous baroreceptor gain was assessed by use of the temporal sequences slope and α index. Modelflow was used to quantify hemodynamics. Symptoms in all patients improved greatly after medication. The autonomic and hemodynamic impairment observed in patients with POTS, particularly after orthostatic stress, is treated effectively with bisoprolol or fludrocortisone or both. These results need further confirmation in a controlled double-blind study. Proper medical treatment improves dramatically the clinical and autonomic-hemodynamic disturbances observed in patients with POTS. The data support the hypothesis that POTS is the result of a hyperadrenergic activation or hypovolemia during orthostasis. KW - Autonomic activity KW - Bisoprolol KW - Fludrocortisone KW - Noninvasive hemodynamics KW - Orthostatic intolerance KW - POTS N1 - Cited By :48 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034500504&doi=10.1007%2fBF02281112&partnerID=40&md5=efa737569d7ec58430f140c9707224a2 ER - TY - JOUR TI - Hemodynamic and symptomatic effects of acute interventions on tilt in patients with postural tachycardia syndrome T2 - Clinical Autonomic Research VL - 10 IS - 1 SP - 29 EP - 33 PY - 2000 DO - 10.1007/BF02291387 AU - Gordon, V.M. AU - Opfer-Gehrking, T.L. AU - Novak, V. AU - Low, P.A. AD - Autonomic Disorders Center, Rochester, MN, United States AB - A variety of approaches have been used to alleviate symptoms in postural tachycardia syndrome (POTS). Drugs reported to be of benefit include midodrine, propranolol, clonidine, and phenobarbital. Other measures used include volume expansion and physical countermaneuvers. These treatments may influence pathophysiologic mechanisms of POTS such as α-receptot dysfunction, β-receptor supersensitivity, venous pooling, and brainstem center dysfunction. The authors prospectively studied hemodynamic indices and symptom scores in patients with POTS who were acutely treated with a variety of interventions. Twenty-one subjects who met the criteria for POTS were studied (20 women, 1 man; mean age, 28.7 ± 6.8 y; age range, 14-39 y). Patients were studied with a 5-minute head-up tilt protocol, ECG monitoring, and noninvasive beat-to-beat blood pressure monitoring, all before and after the administration of an intervention (intravenous saline, midodrine, propranolol, clonidine, or phenobarbital). The hemodynamic indices studied were heart rate (ECG) and systolic, mean, and diastolic blood pressure. Patients used a balanced verbal scale to record any change in their symptoms between the tilts. Symptom scores improved significantly after the patients received midodrine and saline. Midodrine and propranolol reduced the resting heart rate response to tilt (p <0.005) and the immediate and 5-minute heart rate responses to tilt (p <0.002). Clonidine accentuated the immediate decrease in blood pressure on tilt up (p <0.05). It was concluded that midodrine and intravenous saline ate effective in decreasing symptoms on tilt in patients with POTS when given acutely. Effects of treatments on heart rate and blood pressure responses generally reflected the known pharmacologic mechanisms of the agents. KW - POTS, treatmenr, midodrine, saline, β-blocker N1 - Cited By :43 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034465617&doi=10.1007%2fBF02291387&partnerID=40&md5=bb85682466cb12315feb8e9951c9e37c ER - TY - JOUR TI - A case with postural tachycardia syndrome T2 - Equilibrium Research VL - 59 IS - 6 SP - 593 EP - 597 PY - 2000 DO - 10.3757/jser.59.593 AU - Aoki, M. AU - Ando, K. AU - Miyazaki, T. AU - Miyazaki, T. AU - Nishihori, T. AU - Ito, Y. AD - Department of Otorhinolaryngology, Gifu University School of Medicine, Gifu, Japan AB - Postural tachycardia syndrome (POTS) has recently been recognized as a syndrome in which patients have an increased heart rate without orthostatic hypotension. Patients with POTS may complain of presyncope, vertigo, dizziness, light-headedness, general fatigue or unsteadiness. However, the etiology of POTS is unclear. We report a typical case of POTS; a 24 year-old woman who had suffered from dizzy sensations during postural changes for six months. No abnormalities had been observed in ECG, echocardiography, clinical chemistry, blood test and brain MRI. On the first visit, no abnormal responses were noted on neuro-otological examinations or for the CMI and SRQ-D psychological questionnaires. However, the patient's heart rate increased by 34 beats/min from supine to standing position, and in addition, she complained of a headache and fatigue without hypotension during Schellong test. Power spectral analysis of RR interval variability during Schellong test revealed that the normalized powers of low frequency (LFnp) and ratio of LF and high frequency powers (LF/HF) increased when standing upright from supine position. We diagnosed her with POTS and administered atenolol (β1 blocker, 50 mg every morning) in formula, which markedly reduced her subjective symptoms. KW - POTS KW - Power spectral analysis KW - β1 blocker N1 - Cited By :1 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034476717&doi=10.3757%2fjser.59.593&partnerID=40&md5=fb3a630da8099a2d162b10c2e517ac36 ER - TY - JOUR TI - Analysis of heart rate variability during head-up tilt testing in a patient with idiopathic postural orthostatic tachycardia syndrome (POTS) T2 - Japanese Circulation Journal VL - 63 IS - 6 SP - 496 EP - 498 PY - 1999 DO - 10.1253/jcj.63.496 AU - Sumiyoshi, M. AU - Nakata, Y. AU - Mineda, Y. AU - Yasuda, M. AU - Nakazato, Y. AU - Yamaguchi, H. AD - Department of Cardiology, Juntendo University, School of Medicine, Tokyo, Japan AD - Department of Cardiology, Juntendo University, Izunagaoka Hospital, Shizuoka, Japan AD - Department of Cardiology, Juntendo University, School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan AB - A 16-year-old boy was diagnosed with idiopathic postural orthostatic tachycardia syndrome (POTS) during head-up tilt testing. During a passive tilt, the patient's heart rate (HR) increased by 30 beats/min within 5 min. After 25 min of tilting, his HR further increased to 133 beats/min and he began to complain of lightheadedness and weakness without hypotension. Power spectral analysis of HR variability during the tilt test revealed that the ratio of low and high frequency powers increased with the onset of orthostatic intolerance. Propranolol (10mg every morning) dramatically alleviated his clinical symptoms, and he has been asymptomatic with gaining weight after discontinuing his crowded train commuting. KW - Beta-blocker KW - Head-up tilt testing KW - Heart rate variability KW - Orthostatic intolerance KW - Postural orthostatic tachycardia syndrome N1 - Cited By :1 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033012660&doi=10.1253%2fjcj.63.496&partnerID=40&md5=0b1c2d09972ef2da445473f09107a50c ER - TY - JOUR TI - Physiologic changes in pregnant women and their fetuses during jet air travel T2 - American Journal of Obstetrics and Gynecology VL - 154 IS - 5 SP - 996 EP - 1000 PY - 1986 DO - 10.1016/0002-9378(86)90736-2 AU - Huch, R. AU - Baumann, H. AU - Fallenstein, F. AU - Schneider, K.T.M. AU - Holdener, F. AU - Huch, A. AD - Department of Obstetrics, University Hospital, Swissair, Zurich, Switzerland AB - The physiologic reactions of pregnant women and their fetuses were studied during routine commercial flights. Ten healthy pregnant women (32 to 38 weeks of gestation) each undertook two flights. Maternal respiratory and heart rates, transcutaneous Po 2 and Pco 2 , blood pressure, uterine activity, and fetal beat-to-beat heart rate variability were continuously monitored. During these flights, maternal heart rate and blood pressure increased, and Pot decreased significantly while Pco 2 remained unchanged. Respiratory rate showed a short increase during takeoff and landing but remained unchanged during the rest of the flight. Mean fetal heart rate was within normal limits during the whole flight. No bradycardia, prolonged tachycardia, or significant loss of heart rate variability was observed. This study indicates no hazards of commercial flights to the mother and the fetus in uncomplicated pregnancies. © 1986. KW - altitude KW - fetus KW - hypoxia KW - jet air travel KW - maternal anxiety KW - Pregnancy N1 - Cited By :36 N1 - Export Date: 11 October 2019 M3 - Article DB - Scopus UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-0022474765&doi=10.1016%2f0002-9378%2886%2990736-2&partnerID=40&md5=a26d34a84d6e8a6653fb112fbd7ac25e ER -