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21 active trials for Postural Tachycardia Syndrome

Mechanisms of Vasovagal Syncope

Vasovagal Syncope (simple postural faint) is the most common cause of acute loss of consciousness. Postural tachycardia syndrome(POTS) is the most common chronic form of postural lightheadedness. Together they afflict many Americans, mostly young women, who are prevented from gainful employ or school attendance. The underlying mechanism is not known. Our past work suggests that a simple molecule, nitric oxide, acts to subvert normal blood flow controls causing blood to pool in the gut when standing. Our proposal will show the mechanism behind this problem and will indicate effective medical treatments. Patients will be compared to healthy control subjects.

Start: February 2013

Concentration and Attentional Deficits in POTS and Other Autonomic Neuropathies

People with POTS, autoimmune autonomic neuropathy (AAN), pure autonomic failure (PAF), SFN and Ehlers Danlos Syndrome (EDS) do not only suffer from orthostatic symptoms such as dizziness, headache, neck pain, blurred vision or (pre-) syncope. They also experience deficits in attention and concentration (more precisely deficits in selective perspective, operating speed, executive functions and memory performance) mainly in upright position. Only few studies concerning cognitive impairment in autonomic neuropathies, their frequency, aetiology and therapy exist. Many patients concerned, especially with POTS, report attention deficits and "brain fog" with problems in their everyday life and work, predominantly in upright posture. Specific symptomatic or medical therapies do not exist. Medical treatment with Modafinil is discussed and part of a current study at Vanderbilt Autonomic Dysfunction Centre (1-5). The investigators want to investigate if problems of concentration, attention and/or cognitive dysfunction exist in people with POTS, AAN, SFN and EDS compared to healthy controls (HC). Thus the investigators use detailed clinical, autonomic and neuropsychological tests in different body positions (lying, sitting and standing) as also acute therapy (leg crossing).

Start: April 2017

IVIG (Gamunex-C) Treatment Study for POTS Subjects

The purpose of this trial is to evaluate the symptomatic benefits of immunomodulatory treatment with IVIG for POTS (postural tachycardia syndrome) patients with evidence of autoimmunity.

Start: October 2018

Hemodynamic Effects of Compression in POTS

When an individual with Postural Tachycardia Syndrome (POTS) stands up, their heart rate increases significantly (>30BPM) and they may experience symptoms such as lightheadedness, dizziness, shortness of breath, nausea and mental confusion. One commonly prescribed treatment for POTS is compression garments. Compression garments squeeze veins to help return blood back to the heart, which may decrease heart rate and symptoms on standing. However, there is little research about the effectiveness of compression in adults with POTS. In this study, the investigators will use the Lifewrap garment, which compresses the abdomen, pelvis and lower extremities, to evaluate the effectiveness of compression in POTS. The investigators will use a head up tilt (HUT) which will simulate standing. The study participant will participate in 4x 10 minute HUTs wearing 4 different compression configurations: full abdomen and lower extremity compression abdominal only compression leg only compression No compression The investigators hypothesize that with full compression, the participant's heart rate increase from lying down to upright will be lower than when they are not wearing any compression. The investigators will also ask the participant about their symptoms when they are upright. The results of this study could demonstrate the potential benefits of compression and what configuration is most effective. These findings could rapidly translate to the clinical setting, providing improved care.

Start: July 2018

Long-term Effects of Transcutaneous Vagal Nerve Stimulation on Postural Orthostatic Tachycardia Syndrome (POTS)

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.

Start: November 2019

Adrenocorticotropic Hormone Stimulation in Postural Orthostatic Tachycardia Syndrome (POTS)

This study is to determine different chemical levels in the blood during a low salt diet. This study will compare normal volunteers to those with Postural Tachycardia Syndrome (POTS)

Start: January 2013

Aldosterone & Sodium Regulation in Postural Tachycardia Syndrome - Screening

The purpose of the study is to determine whether patients meet criteria for Postural Tachycardia Syndrome (or not) and have reduced blood volume (or not). Both of these are important screening elements to Aim 3 of a National Institutes of Health Grant. The purposes of Aim 3 are to determine 1. whether a high dietary sodium level appropriately expands plasma volume in Postural Orthostatic Tachycardia, 2. whether plasma renin activity and aldosterone are modified appropriately by changes in dietary sodium in Postural Tachycardia Syndrome and 3. whether patients with Postural Tachycardia Syndrome have improvements in their orthostatic tachycardia and symptoms as a result of a high dietary sodium level.

Start: February 2013

Muscular and Cutaneous Dysfunction in POTS

POTS patients seem to experience orthostasis-dependent muscle weakness and pain as well as increased muscle fatigue upon physical activity, which can be improved by regular aerobic exercise. However, reduced sweat production of the extremities with limited control of the body temperature leads to exercise intolerance, so that sticking to a training program becomes a challenge for most patients. Recordings of MVRCs provide a new tool to assess muscle membrane dysfunction, depending on ischemia, surface temperature and training. As muscle dysfunction is assumed to be present in the majority of POTS patients but has not yet been scientifically studied the present study aims at understanding the muscular and cutaneous functioning in POTS using MVRC recordings, dependent both on orthostatic stress and exercise training as well as body temperature regulation. Our main hypothesis is that POTS patients experience functional muscle dysfunction that may be linked to altered muscle perfusion or body temperature regulation. The purpose of this study is to examine muscular and cutaneous dysfunction in POTS in order to i) better understand the underlying pathology for symptoms and to ii) ultimately improve treatment options.

Start: January 2020

Alterations of Attention in POTS Depending on Body Position and Hydration

The Postural Tachycardia-Syndrome (POTS) is a form of autonomic dysregulation, typically accompanied by symptoms of orthostatic intolerance (OI). OI is defined by the inability to tolerate the upright position and is improved by lying down. POTS is considered a syndrome that may include a number of several disorders. Symptoms should be persistent for at least 6 months to reach a diagnosis. It is characterized by a sustained heart rate (HR) increment of 30 beats/min or more within 10 min of standing or head-up tilt (HUT) in adults, in the absence of orthostatic hypotension and with the presence of symptoms of OI. In children and adolescents a diagnosis requests a HR increment of at least 40 beats/min. The increment in HR when moving to an upright posture is often a response to a reduction in venous return, causing excessive blood pooling in the lower limbs. The symptoms present in POTS vary greatly. Typical symptoms are lightheadedness, dizziness, blurred vision, mental clouding ("brain fog") or cognitive dysfunction. Other symptoms may present as palpitations or chest pain. Additional symptoms consist of postural headaches, nausea, sleep disturbances, fatigue and gastrointestinal dysfunction. The manifestation of symptoms in POTS varies in severity, frequency and combination, resulting in POTS being a very heterogenous and subjective disorder. Symptoms can be severe and often make simple daily activities difficult to an extent that compromises the patients quality of life. Typically symptoms exacerbate in the mornings, after physical activity, after eating and during menstruation. This study objective is to examine the occurrence, mechanisms and causes of impaired attention in POTS as well as to test the effect of acute water ingestion for attention in POTS. The investigators therefore conduct a study including patients with POTS and healthy volunteers. All participants will receive a dossier of five self-assessment questionnaires after giving informed consent. Clinical examination includes 2 HUT-tests while standing for 15 minutes, conventional measuring of blood pressure, continuous recording of NIRS signals during testing, determination of pupil size, the diameter of the optic nerve and Neuropsychological testing (Test of Attentional Performance, mobility version" (TAP-M), Go/NoGo Test, Divided Attention Test)

Start: September 2017

POTS Adrenergic Ab (CIHR Aims #1&2)

Objective: In this pilot study, we will test the hypothesis that patients with POTS (age 18-60 years) will have a higher percentage of functional antibodies to adrenergic receptors compared with control subjects without POTS.

Start: January 2016

Hypercapnia and Orthostatic Tolerance in Postural Orthostatic Tachycardia Syndrome

The mechanism behind postural orthostatic tachycardia syndrome (POTS) involves many causes including a sympathetic nervous system problem. Blood gases, like carbon dioxide (CO2), have an important effect on sympathetic activation. The purpose of this research study is to determine if higher CO2 levels have any effect in lowering heart rate and reducing POTS symptoms when upright/standing. The investigators are also searching for the ideal CO2 concentration to achieve the most effective response

Start: May 2021

Crossover Study of Propranolol vs Ivabradine in POTS

1.0 BACKGROUND Postural tachycardia syndrome (POTS) is a disorder of chronic orthostatic intolerance characterized by symptoms of palpitations, lightheadedness, chest discomfort, shortness of breath, blurred vision, and mental clouding. These symptoms occur during standing and are associated with a marked increase in heart rate (HR) in the absence of hypotension, which typically resolve when sitting or lying down. Most importantly, POTS is associated with a very poor quality of life and significant functional disability. POTS patients commonly experience mental clouding ("brain fog") even while lying down or seated, which poses significant limitations to daily activities . Unfortunately, there is a relative paucity in the literature assessing therapies for POTS patients. Given that excessive tachycardia on standing is a fundamental component of this syndrome, a handful of studies have evaluated medications that reduce HR. Ivabradine is newer drug that is a selective If channel blocker that reduces HR without affecting other cardiovascular functions. 2.0 RATIONALE / STUDY PURPOSE The investigators propose to compare the efficacy of propranolol and ivabradine on HR response to standing, and symptom burden in patients with POTS. 3.0 Study Design This will be a single-center double-blind placebo-controlled randomized crossover trial conducted in patients with POTS to compare effects of (1) oral ivabradine 5 mg bid plus placebo BID (to fill out a QID schedule); (2) oral propranolol 20 mg qid; and (3) oral placebo qid in POTS patients. After a baseline screening assessment following a washout period of 7 days, participants will be randomized to start with a 4-week course of either ivabradine, propranolol or placebo. The other two treatments will be given in separate 4-week courses with a 7-day washout period between phases, with each participant acting as his or her own control. At the end of each 4-week phase, participants will complete the symptom-rating and HRQOL questionnaires, and also undergo tilt table testing to assess the change in HR at 10 min with head up tilt. Participants will undergo POTS testing at baseline and at the end of each 4-week treatment course. This will involve a total of 4 separate study visits.

Start: February 2021

Autonomic Determinants of POTS - Pilot 2

Postural tachycardia syndrome (POTS) is a relatively common condition affecting mostly otherwise healthy young women. These patients have high heart rate and disabling symptoms during standing. Quality of life may be poor. The sympathetic nerves in the autonomic nervous system help to maintain normal blood pressures and heart rates during activities of daily life. The purpose of this study is to determine the importance of sympathetic activation as a cause of orthostatic symptoms. The investigators will assess the effects of a blood pressure medication (Moxonidine) on the symptoms during standing. Moxonidine lowers sympathetic activity. The investigators believe patients with high resting sympathetic activity might benefit from Moxonidine. It might reduce high heart rate and improve symptoms during standing. This study should help clinicians and the growing population of patients with POTS gain a better understanding of this disorder and find more personalized treatment.

Start: June 2021

fMRI in Postural Tachycardia Syndrome

Postural tachycardia syndrome (POTS) is one of the most common forms of chronic orthostatic intolerance in the United States. This is a disabling disorder characterized by an excessive increase in heart rate upon standing that is accompanied by symptoms such as dizziness and fatigue. One of the most under appreciated and bothersome symptoms of POTS is impaired cognition or "brain fog," which occurs to a level that interferes with daily activities such as work and education. Despite this high impact, the reasons why POTS patients have problems with cognition are not well understood. This project will test the overall hypothesis that "brain fog" in POTS is related to increased activation of cognitive brain regions during mental tasks when compared with healthy subjects, and that this activation is exacerbated by in the presence of orthostatic stress.

Start: August 2021

Autonomic Determinants of POTS - Pilot1

Postural tachycardia syndrome (POTS) is a relatively common condition affecting mostly otherwise healthy young women. It is the cause of significant disability and an impairment in quality of life. These patients have high heart rate and symptoms during standing. Many of these patients are disabled and have a poor quality of life. The sympathetic nerves are part of the nervous system that helps to maintain normal blood pressures and heart rates during activities of daily life. The purpose of this study is to determine the importance of sympathetic activation as a cause of orthostatic symptoms. The investigators will assess the effects of a blood pressure medication (Moxonidine) on the symptoms during standing. Moxonidine lowers sympathetic activity. The investigators believe patients with high resting sympathetic activity might benefit from Moxonidine. It might reduce high heart rate and improve symptoms during standing. This study should help clinicians and the growing population of patients with POTS gain a better understanding of this disorder and find more personalized treatment.

Start: August 2019

Modafinil and Cognitive Function in POTS

A common complaint among patients with Postural Tachycardia Syndrome (POTS) is "brain fog" or difficulty concentrating. This problem is poorly understood. The purpose of this study is to better understand the cognitive dysfunction associated POTS, and to determine optimal treatment strategies for this condition. In this study, the investigators will test the hypothesis that acute administration of the psychostimulant drug modafinil can improve seated measures of cognitive function in patients with POTS.

Start: October 2014

Autoimmune Basis for Postural Tachycardia Syndrome

The purpose of this study is to see if some people with postural tachycardia syndrome (POTS) have higher levels of immune proteins (autoantibodies) directed against receptors of the autonomic nervous system, and if these autoantibodies make a difference in their POTS symptoms. The investigators also want to see if the levels of these autoantibodies stay the same over time.

Start: February 2016

Vagal Stimulation in POTS

The purpose of this study is to investigate how the electrical stimulation of a nerve in the skin of the earlobe (transcutaneous vagal nerve stimulation), alone or in combination with two medications (galantamine and pyridostigmine), affects the way the autonomic (involuntary) nervous system controls heart rhythm, symptoms on standing, and inflammatory markers in female patients with postural tachycardia syndrome (POTS). The study consists of 2 parts: a screening (1-2 study days), and 3 testing days. The study will take 5 days total and about 16 participants will be screened for the study. The investigators estimate 13 will be eligible to participate in all of the study days.

Start: September 2017

Breathing Device in Postural Orthostatic Tachycardia Syndrome (POTS)

The investigators will test whether breathing through an inspiratory resistance device will improve the ability to be upright and decrease heart rate increases on standing in patients with postural tachycardia syndrome.

Start: October 2009

POTS NET mRNA Functional Correlation With NET Activity

DNA Acetylation can be responsible for significant down-regulation of transcription of the Norepinephrine Transporter (NET). NET is an important clearance transporter that removes norepinephrine (NE) from sympathetic neuronal synapses. Very low levels of NET can "cause" Postural Tachycardia Syndrome (POTS) or make these patients more susceptible to certain medications. Quantified NET messenger RNA (mRNA) levels from a peripheral blood sample may be able to assess NET availability, which is simpler than older methods. This has not been validated against NET function. In this protocol, the investigators seek to assess whether these NET mRNA levels correlate with NET function. The investigators will assess the DHPG (NET dependent NE metabolite):NE ratio in POTS patients and control subjects from both plasma and urine samples.

Start: July 2017