Active clinical trials for "Postural Orthostatic Tachycardia Syndrome"

The investigators will test to determine if an external Automated Abdominal Binder (non-commercial product) during high sodium diet improves orthostatic tolerance, compared to wearing the binder during a low sodium diet session.

Background: - The autonomic nervous system helps control things that happen automatically in the body, like blood pressure, heart rate, and digestion. When it doesn t work properly, it s called dysautonomia. Researchers want to learn more about dysautonomias and train doctors to learn how to better diagnose them. Objectives: To allow people with autonomic disorders to be evaluated. To help fellows in the NIH Autonomic Disorders fellowship program see a variety of diseases in their training. Eligibility: People age 18 and older with dysautonomia; children over age 2 if they might benefit Healthy adult volunteers Design: Participants will have different procedures depending on their symptoms. They will have one or more visits. They will have some but not all of the tests below. Participants will have a medical history and physical exam. They may be tested for problems thinking. They may complete a symptom questionnaire. They may have their temperature and blood pressure taken. Participants may have an intravenous line placed. A needle will guide a thin plastic tube into an arm vein. Participants may have blood drawn several times. They may give a urine sample. Participants may have an electrocardiogram. How much blood a participant s heart is pumping and/or how much blood is flowing through their arm may be measured. The total amount of blood in their bloodstream may be measured. Participants may have their ability to sweat and/or sense of smell tested. Breathing, bowel sounds, and/or body functions may be monitored. Pupil size, response to environmental temperature changes, and/or breathing may be measured. Participants may have a bladder ultrasound. Small pieces of skin may be taken for study.

The investigators hope to learn the feasibility and preliminary efficacy of the Embr device for improving thermal comfort in individuals with POTS and impaired thermoregulation. Feasibility will be assessed via usage of the Embr device and participant feedback. Preliminary efficacy measures will include temperature-related symptoms and temperature- related quality of life in individuals with POTS and impaired thermoregulation.

Postural tachycardia syndrome (POTS), is the chronic form of orthostatic intolerance associated with excessive upright tachycardia, and occurs predominantly in young females (>85%). Among its most troubling symptoms are lightheadedness, fatigue, and decreased memory often called "brain fog" by patients. Task-related neurovascular coupling (NVC) links neural activity to an increase in CBF known as "functional hyperemia". Although memory task performance and NVC deteriorated with angle of tilt in POTS but not healthy controls, cerebral blood flow (CBF) remained similar to control. Instead, the investigators observed extensive narrow band low frequency (0.07-0.13 Hz) oscillations in BP (OBP) that entrained and amplified oscillations in CBF (OCBF). OBP and OCBF increased with tilt angle and caused impaired working memory and reduced functional hyperemia. The cardiovagal baroreflex couples BP to HR to buffer BP changes. The investigators hypothesize that the cardiovagal baroreflex becomes progressively impaired with orthostasis in POTS, but not in healthy volunteers, and accounts for OBP, OCBF, and loss of NVC; further, improving the baroreflex reduces OBP, OCBF and Brain Fog in POTS.

This study uses an Alizarin Red powder mixture to characterize the sweat distributions in youth during tilt table testing. Patients with a known orthostatic sweat response from a prior clinical tilt table test in the investigators laboratory will be recruited. The Alizarin Red powder will be applied to exposed skin, and quantitative sweat will be measured at the thigh. During tilt testing, serial photos will be taken once the sweat response occurs. Sweat distributions will be compared during syncope (orthostatic sweat), during periods of anxiety (emotional sweat), and in patients with POTS (with and without syncope).

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).

The purpose of this study is to determine the role of the renin-angiotensin-aldosterone in the pathophysiology of postural tachycardia syndrome, and to provide an insight about the disease process in this disorder.

This study will investigate the relationship between susceptibility to hypnosis and regulation of the autonomic nervous system (nerves that control involuntary body functions, such as heart rate and sweating). Hypnosis is a state of mind in which the individual is highly focused, relatively unaware of his or her surroundings, and possibly more able to accept and use therapeutic suggestions. People vary in their responsiveness, or susceptibility, while in hypnosis. People with certain conditions, such as chronic fatigue syndrome (CFS), chronic pain, posttraumatic stress disorder (PTSD), and generalized anxiety disorder (GAD) have altered hypnotic susceptibility. Patients with chronic orthostatic intolerance (COI) often have symptoms similar to those of individuals with CFS, chronic pain, PTSD, and GAD, and this study will examine how patients with COI respond to hypnosis as compared with healthy normal volunteers. COI is a group of disorders characterized by intolerance to prolonged standing. Among them are neurocardiogenic syncope (NCS), in which patients have recurrent episodes of sudden loss of consciousness, and postural tachycardia syndrome (POTS), in which patients have a sustained increase in heart rate after standing. In addition to the comparison of COI and normal volunteer responses to hypnosis, the study will examine how hypnotic susceptibility is related to the ability to control autonomic functions such as blood pressure, heart rate, and sweating. The autonomic nervous system is activated when the body is stressed, not only from physical stimuli such as cold temperature, but also from mental stimuli, such as seeing a rattlesnake up close. Hypnosis may, therefore, be a useful tool to understand how the mind controls the autonomic nervous system. Healthy normal volunteers and patients with NCS or POTS who are 18 years of age or older may be eligible for this two-part study. In part 1, participants complete a questionnaire and are then tested for hypnotic susceptibility. For this test, a professionally trained physician guides the subject through a procedure to achieve a hypnotic state. The subject is asked to perform several simple tasks and is then guided back to a normal state of being. In part 2, the subject undergoes hypnosis again, during which the physician offers various suggestions while monitoring activity of the subject's autonomic nervous system. The subject is connected to various sensors that continuously monitor blood pressure, heart rate, blood flow, sweat response, skin electrical conduction, and brain wave activity. An intravenous catheter is inserted into an arm vein to collect blood samples. At the end, the subject is guided back to a normal state of being. The hypnosis session in part 1 is videotaped in order to: 1) permit review by a scientist who is unaware of the subject's condition and whose judgment will not, therefore, be biased; and 2) have a record of the experimental data. Only qualified investigators will view the videotape.

Pilot-case-control study on exertion and orthostatic intolerance of adolescents with myalgic encephalomyelitis/ chronic fatigue syndrome (ME/CFS) compared to age-matched healthy controls (HC).

It is known that 33-50% of Classic and Hypermobile Ehlers-Danlos Syndrome patients eventually develop dysautonomia, otherwise known as "POTS" (Postural Orthostatic Tachycardia Syndrome). Some of these patients develop dysautonomia as a result of a retroflexed odontoid, Chiari 1 Malformation or cranial settling and the resulting basilar impression. Many Ehlers-Danlos patients suffer with the same symptomology with no evidence of a cause according to MRI imaging. It is the author's hypothesis that low-level External Communicating Hydrocephalus appears to be responsible for the constellation of autonomic and cranial nerve symptoms, and if present in the very young, an analysis of head circumference growth in the first 15 months of life should reflect abnormally rapid head growth, supporting this hypothesis.