| Not Yet Recruiting | The Impact of Improved Vagal Function on Periaqueductal Gray Connectivity NCT05618067 | Virginia Commonwealth University | N/A |
| Not Yet Recruiting | Ultrasound Guided Stellate Ganglion Block in Postural Tachycardia Syndrome NCT06953661 | Stanford University | N/A |
| Completed | Non-invasive Vagal Neurostimulation (nVNS) in Adolescents With Postural Orthostatic Tachycardia Syndrome (POTS NCT06268288 | Mayo Clinic | N/A |
| Recruiting | Periaqueductal Gray-vagus Nerve Interface Malfunction Explain the Natural History With Its Numerous Co-morbidi NCT05618054 | Virginia Commonwealth University | N/A |
| Completed | VNS for Long-COVID-19 NCT05630040 | Icahn School of Medicine at Mount Sinai | N/A |
| Active Not Recruiting | Phenotyping Mitochondrial and Immune Dysfunction in POTS With Targeted Clinical Intervention. NCT05409651 | University of California, San Diego | N/A |
| Recruiting | Inappropriate Sinus Tachycardia Registry NCT05107635 | AtriCure, Inc. | — |
| Completed | A Novel Noninvasive Thermoregulatory Device for Postural Tachycardia Syndrome NCT04943276 | Stanford University | N/A |
| Active Not Recruiting | fMRI in Postural Tachycardia Syndrome NCT04137757 | Milton S. Hershey Medical Center | N/A |
| Recruiting | Hypercapnia and Orthostatic Tolerance in Postural Orthostatic Tachycardia Syndrome NCT04271878 | University of Calgary | N/A |
| Active Not Recruiting | Autoimmune Basis for Postural Tachycardia Syndrome NCT05043051 | University of Oklahoma | N/A |
| Active Not Recruiting | Autonomic Determinants of POTS - Pilot 2 NCT04140721 | Vanderbilt University Medical Center | EARLY_Phase 1 |
| Recruiting | Crossover Study of Propranolol vs Ivabradine in POTS NCT04186286 | University of Calgary | Phase 2 |
| Completed | Muscular and Cutaneous Dysfunction in POTS NCT04170725 | Insel Gruppe AG, University Hospital Bern | N/A |
| Unknown | Long-term Effects of Transcutaneous Vagal Nerve Stimulation on Postural Orthostatic Tachycardia Syndrome (POTS NCT04632134 | Istituto Clinico Humanitas | N/A |
| Recruiting | Autonomic Small Fiber Neuropathy and Ehlers Danlos Syndromes - Prospective Study and Registry NCT04310644 | RWTH Aachen University | — |
| Active Not Recruiting | Autonomic Determinants of POTS - Pilot1 NCT04050410 | Vanderbilt University Medical Center | EARLY_Phase 1 |
| Completed | IVIG (Gamunex-C) Treatment Study for POTS Subjects NCT03919773 | University of Texas Southwestern Medical Center | Phase 1 / Phase 2 |
| Completed | Hemodynamic Effects of Compression in POTS NCT03484273 | University of Calgary | N/A |
| Completed | Standing Cognition and Co-morbidities of POTS Evaluation NCT03602482 | Milton S. Hershey Medical Center | N/A |
| Active Not Recruiting | Vagal Stimulation in POTS NCT03124355 | Vanderbilt University Medical Center | Phase 1 |
| Completed | Alterations of Attention in POTS Depending on Body Position and Hydration NCT03253120 | Insel Gruppe AG, University Hospital Bern | N/A |
| Active Not Recruiting | POTS NET mRNA Functional Correlation With NET Activity NCT03218761 | Vanderbilt University Medical Center | — |
| Completed | Gastrointestinal Symptoms in Postural Orthostatic Tachycardia Syndrome NCT03263819 | Vanderbilt University Medical Center | — |
| Completed | Concentration and Attentional Deficits in POTS and Other Autonomic Neuropathies NCT03681080 | RWTH Aachen University | N/A |
| Enrolling By Invitation | Autoimmune Basis for Postural Tachycardia Syndrome NCT02725060 | Vanderbilt University Medical Center | N/A |
| Recruiting | POTS Adrenergic Ab (CIHR Aims #1&2) NCT02673996 | University of Calgary | — |
| Completed | Qualitative Sweat Distribution During Tilt Table Procedure NCT02329548 | Nationwide Children's Hospital | N/A |
| Active Not Recruiting | Modafinil and Cognitive Function in POTS NCT01988883 | Vanderbilt University Medical Center | EARLY_Phase 1 |
| Terminated | Clinical Autonomic Disorders: A Training Protocol NCT02154009 | National Institute of Neurological Disorders and Stroke (NINDS) | — |
| Completed | EEG Characteristics in Youth POTS and/or Syncope NCT02167412 | Nationwide Children's Hospital | — |
| Completed | Mechanisms of Vasovagal Syncope NCT01791816 | New York Medical College | EARLY_Phase 1 |
| Active Not Recruiting | Aldosterone & Sodium Regulation in Postural Tachycardia Syndrome - Screening NCT01783288 | Vanderbilt University | N/A |
| Completed | Adrenocorticotropic Hormone Stimulation in Postural Orthostatic Tachycardia Syndrome (POTS) NCT01764711 | Vanderbilt University | N/A |
| Unknown | The Effect of Ivabradine on Patients With Postural Tachycardia Syndrome NCT01761825 | Tel-Aviv Sourasky Medical Center | Phase 2 |
| Completed | Cognitive Dysfunction in Postural Tachycardia Syndrome NCT01366963 | Vanderbilt University | — |
| Completed | Assessment of Vascular Endothelial Function in Postural Tachycardia Syndrome NCT01308099 | Vanderbilt University Medical Center | — |
| Completed | Local Vasoconstriction in Postural Tachycardia Syndrome NCT01210430 | New York Medical College | EARLY_Phase 1 |
| Active Not Recruiting | Intravenous (IV) Saline and Exercise in Postural Tachycardia Syndrome (POTS) NCT01000350 | Vanderbilt University Medical Center | N/A |
| Active Not Recruiting | Breathing Device in Postural Orthostatic Tachycardia Syndrome (POTS) NCT00962728 | Alfredo Gamboa | N/A |
| Completed | Effect of Exercise in OI NCT00770484 | Vanderbilt University | N/A |
| Active Not Recruiting | Sleep Actigraphy in Postural Tachycardia Syndrome (POTS) NCT00692471 | Satish R. Raj | — |
| Completed | Peripheral Dopamine in Postural Tachycardia Syndrome NCT00685919 | Vanderbilt University | Phase 2 / Phase 3 |
| Completed | Autonomic Nervous System and Chronic Fatigue Syndrome NCT00580619 | Vanderbilt University | Phase 1 |
| Active Not Recruiting | Acute Salt Handling in Orthostatic Intolerance NCT00581633 | Vanderbilt University | N/A |
| Completed | Objective Sleep Disturbances in Orthostatic Intolerance NCT00581022 | Satish R. Raj | — |
| Recruiting | A Study of Pyridostigmine in Postural Tachycardia Syndrome NCT00409435 | Mayo Clinic | Phase 2 |
| Terminated | Dopamine in Orthostatic Tolerance NCT00748228 | Vanderbilt University | N/A |
| Completed | Hypnosis in Autonomic Function NCT00061009 | National Institute of Neurological Disorders and Stroke (NINDS) | — |