Active clinical trials for "Postural Orthostatic Tachycardia Syndrome"

A common complaint among people with Postural Tachycardia Syndrome (POTS) is "brain fog" or difficulty concentrating. This is very poorly understood. To better understand this cognitive dysfunction, the investigators will test people with POTS and people without POTS using various neuropsychiatric instruments. The investigators hypothesis is that people with POTS will have greater abnormalities on neuropsychiatric testing than normal controls.

The investigators will test the hypothesis that markers of vascular endothelial dysfunction will be exaggerated acutely with an extreme high sodium diet compared to an extreme low-sodium diet. The investigators will compare patients with postural orthostatic tachycardia (POTS) to healthy control subjects.

Patients with POTS experience significant gastrointestinal symptoms. Current evidence suggesting that abnormal post-ganglionic sympathetic function could play a role in the pathophysiology of these GI abnormalities. Sympathetic fiber regulate motor and the postprandial GI peptides secretion. The focus of the present proposal is to determine glucose homeostasis, GI motility, and their association with GI and cardiovascular symptoms in POTS patients versus healthy controls. Furthermore, we will determine differences in these outcomes in POTS patients with and without evidence of postganglionic sympathetic fiber neuropathy. As a long-term goal, this study can lead us to understand the pathophysiology of common co-morbidities in patients with POTS to provide new treatment approaches and prevention strategies.

The purpose of this study is to see if people with Postural Tachycardia Syndrome (POTS) have different levels of certain chemicals in their blood than people who don't have POTS. This study will test whether the blood vessels of people with POTS will react differently to certain tests than people without POTS. The hypothesis of the study is: Patients with POTS will have vascular endothelial dysfunction compared with control subjects.

Orthostatic intolerance refers to symptoms that occur with standing and improve or resolve with recumbency. Few studies have evaluated orthostatic intolerance symptoms by electroencephalography (EEG), and none of those studies have focused on the adolescent-aged patient. This study will compare EEG characteristics and sweat rate during head-upright tilt (HUT) testing among patients with postural tachycardia syndrome (POTS) and patients with syncope without POTS. Patients with POTS will also undergo a separate HUT with abdominal and lower extremity compression. The primary aim of this study is to characterize video EEG changes that correspond with orthostatic intolerance in youth during HUT testing. The investigators hypothesize that the clinical encephalopathy related to POTS and referred to as 'brain fog' will have an electrographic correlate. Secondary aims include (1) EEG comparisons of POTS symptoms with and without abdominal and lower extremity compression during HUT, (2) correlation between sweat rate and EEG changes during HUT, and (3) analysis of EEG characteristics that distinguish syncope with POTS from syncope without POTS. The investigators hypothesize that POTS patients have prolonged syncopal prodromes (compared to syncope patients without POTS) which are protective of syncope during daily activities.

The purpose of this study is to evaluate cognition in patients with postural tachycardia syndrome (POTS) while lying down and standing and to assess the prevalence of hypermobile Ehlers-Danlos Syndrome in POTS.

Dysautonomia, primarily defined as postural orthostatic tachycardia syndrome (POTS) can seriously disrupt a child's daily activities. It is most commonly associated with nausea or abdominal pain. In preliminary studies, when orthostatic intolerance was treated with fludrocortisone, a standard therapy for orthostatic intolerance (OI), symptomatic improvement in nausea was observed. However, children with POTS were also observed to have higher supine mean arterial pressure (MAP) (preliminary data) and greater suppression of the baroreceptor reflex sensitivity (BRS) occurred upon up-right tilt. While fludrocortisone alleviates nausea associated with OI, its long-term use may pose long term health risks to children including worsening hypertension. Therefore, it is the objective of this study to define the mechanism for OI as it relates to nausea. The investigators hypothesize that OI resulting from changes in the autonomic nervous system is the likely mechanism for the nausea observed in the patients in this study. The investigators further hypothesize that this is potentially an early marker for future cardiovascular problems such as early onset hypertension and cardiac hypertrophy. The general objective of this protocol is to address this gap in knowledge by determining the autonomic characteristics of children with OI as well as defining neurohumoral profiles for these subjects to better understand the cause of the elevated supine in these subjects. By better understanding the potential mechanism for this condition, it is the investigators future goal to develop a more focused and safer treatment strategy. The investigators will study subjects between 10 to 18 years of age utilizing the tilt table to mimic daily life stressors and also measure serum levels of epinephrine, norepinephrine, rennin, angiotensin II, aldosterone, and vasopressin at baseline and during tilt. This study will generate data with high impact in that more rational treatments for management of dysautonomia could be chosen on the basis of the profile of dysautonomia and neurohumoral markers.

The study compares three treatment modalities in a human model of Postural orthostatic tachycardia syndrome (POTS): beta-blockers, I(f)-blockers, and placebo.

Retrospectively review the charts of all children who had heart rate variability, deep breathing test, valsalva maneuver, tilt table test, thermoregulatory sweat testing, quantitative sudomotor axon reflex test (QSART) completed and were cared for at Children's Hospital of Wisconsin.

The investigators aim to study whether the Compensatory Reserve Index (CRI) (an FDA approved device that assesses intravascular volume) can be used to evaluate severity of Postural Orthostatic Tachycardia Syndrome (POTS) and whether the CRI value has a correlation with severity of psychosocial symptoms and functional impairment associated with POTS.