Active clinical trials for "Postural Orthostatic Tachycardia Syndrome"

The purpose of the proposed research is to determine how changes in kidney dopamine (DA) activity influence urinary sodium excretion. We will decrease DA activity in the kidney by inhibiting DA synthesis via carbidopa administration. We want to compare findings in normal volunteers and in patients with postural tachycardia syndrome (POTS). We will test the null hypothesis (Ho) that the effects of oral carbidopa administration on urinary sodium excretion will not differ between patients with POTS and healthy volunteers.

The purpose of this research is to evaluate if a hybrid semi-supervised remote exercise training program can reduce symptoms and improve quality of life and physical fitness in individuals with postural orthostatic tachycardia syndrome (POTS) and determine if this program is more effective than current standard of care.

Patients with POTS may not adequately expand their plasma volume in response to a high-sodium (Na+) diet. Mechanisms involved in the regulation of plasma volume, such as the renin-angiotensin-aldosterone system and renal dopamine, may be impaired in POTS and may respond inappropriately to changes in dietary sodium.The purpose of this study is to determine (1) whether a high dietary sodium level appropriately expands plasma volume in POTS; (2) whether plasma renin activity and aldosterone are modified appropriately by changes in dietary sodium in POTS; and (3) whether patients with POTS have improvements in their orthostatic tachycardia and symptoms as a result of a high dietary sodium level.

The investigators propose to test the hypothesis that the sympathetic nervous system contributes to the cardiovascular and inflammatory abnormalities present in the chronic fatigue syndrome (CFS) and, in particular in the subset of patients characterized by postural tachycardia syndrome (POTS). CFS and POTS are seen mostly in otherwise normal young women, and are the cause of significant disability. A substantial proportion of patients referred for evaluation of POTS met diagnostic criteria for CFS and, conversely, a subset of patients referred for treatment for CFS have POTS. The investigators hypothesize that sympathetic activation underlies the pathophysiology of patients in whom CFS and POTS overlap (CFS-P).

Patients with Postural Tachycardia Syndrome (POTS) may not adequately expand their plasma volume in response to a high sodium diet. Mechanisms involved in the regulation of plasma volume, such as the renin-angiotensin-aldosterone system and renal dopamine (DA), may be impaired in POTS and may respond inappropriately to changes in dietary sodium. The investigators propose that the changes in urinary sodium and dopamine excretion caused by consuming low-sodium and high-sodium diets will be different between patients with POTS and healthy volunteers. The purpose of this study is to determine (1) whether changes in dietary sodium level appropriately influence sodium excretion in POTS; (2) whether changes in dietary sodium level appropriately influence DA excretion in POTS; (3) whether a high dietary sodium level appropriately expands plasma volume in POTS; and (4) whether patients with POTS have improvements in their orthostatic tachycardia and symptoms as a result of a high dietary sodium level.

The purpose of this study is to learn how plants can play a role in gain/loss of sodium in the urine and in the regulation of blood pressure. Dopamine is a chemical mostly present in the brain and kidneys which assists in regulation of the body's salts (sodium and potassium). Fava beans contain a lot of the chemical that increases the production of dopamine by the kidneys. The purpose of these studies is to characterize the diuretic effects of dietary catecholamine sources in healthy individuals. Specific aims are: To determine the effect of dietary dopa sources on plasma and urinary catecholamines. To investigate the capacity of botanical dopaminergic agents (fava beans) to induce natriuresis in a short term study. To provide preliminary data on the effects of dietary dopa on heart rate and blood pressure. In these studies, we will test the null hypothesis (Ho) that urinary sodium excretion will not differ in healthy volunteers after consumption of a fixed-sodium study diet and the study diet plus fava beans.

Postural Orthostatic Tachycardia Syndrome (POTS) is characterized by symptoms of chronic orthostatic intolerance such as fatigue, lightheadedness, dizziness, palpitations and by pronounced tachycardia upon standing. The aims of the present research study are to test whether a daily transcutaneous vagal nerve stimulation (tVNS) performed for 14 consecutive days may improve heart rate response and reduce disabling symptoms while standing.

The purpose of this study is to determine whether Ivabradine is an effective treatment for postural tachycardia syndrome.

We and others have shown that many younger patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) have orthostatic intolerance (OI), i.e., they can't tolerate prolonged standing. OI in ME/CFS is often accompanied by either postural tachycardia syndrome (POTS) in which standing results in an excessive heart rate, and neurally mediated hypotension (NMH) in which standing causes a fall in blood pressure and fainting. Intravenous fluids can alleviate these symptoms, but is difficult to administer; oral fluids fail to provide the same benefit. We would therefore like to test the effectiveness of an oral rehydration solution (ORS, W.H.O. formula) making use of co-transport of glucose and sodium, to reverse these symptoms in ME/CFS subjects with POTS or NMS, and will compare these results with healthy control subjects.

Postural orthostatic tachycardia (POTS) is characterized by abnormalities in the autonomic nervous system in the body. The autonomic nervous system controls and regulates body functions such as heart rate, breathing, digestion, and more. The investigator has shown that patients with POTS have higher cardiovascular and adrenergic activating autoantibodies (AAb), which likely changes the normal make-up of POTS. There are autoantibodies that have been suggested by a few reports of their presence in POTS, but their role different aspects of POTS is unknown. The study will look at the body's responses in patients with POTS. The crossover study design is to have half of the patients will start with sham followed by active stimulation and half will start by active followed by sham stimulation. It is anticipated that results will provide a potential therapeutic approach based on the understanding of POTS.