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NCT00409435
This is a 3-day study comparing pyridostigmine versus placebo in the treatment of postural tachycardia syndrome (POTS). The researchers expect pyridostigmine to improve tachycardia and stabilize blood pressure.
NCT05618067
This study is being to see if participating in breathing exercise training and practicing this training will help with Postural tachycardia syndrome (POTS). The information may help doctors to learn more about how the different parts of people's brains communicate.
NCT07189936
Long COVID is defined by a range of symptoms affecting multiple organs that persist for more than three months following an acute SARS-CoV-2 infection. Approximately 7% of individuals who recover from SARS-Cov-2 infection develop Long COVID. Long COVID Postural Orthostatic Tachycardia Syndrome (LCPOTS) symptoms include fatigue, exercise intolerance, orthostatic intolerance, syncope, and heightened orthostatic tachycardia. Research has found that decreased parasympathetic activity in LCPOTS increases the production of highly immunogenic neoantigens Isolevuglandins (IsoLG-adducts). IsoLG-adducts induce formation of circulating monocyte/T cell complexes(doublets) leading to the persistent and unresolved immune response that continues after the initial infection. The purpose of the this research, is to study the effects of 2-hydroxybenzylamine (2-HOBA), an Iso-LG-adduct scavenger, its effects in immune markers and compare it with Placebo
NCT05421208
The term post-acute COVID-19 syndrome or Long COVID is a disabling syndrome that persists beyond the 3-month convalescence period after COVID-19 infections. This syndrome affects mostly women (\~80%), present with chronic tachycardia and Orthostatic intolerance symptoms without any identifiable cause. In addition, non-specific symptoms such as fatigue, headache, and "brain fog", commonly described in POTS patients are also present in this novel condition, recently named post-COVID-19 tachycardia syndrome, POTS variant. Reduced Vagal activity and unresolved inflammation is post-COVID-19 POTS is hypothesized as the cause of Long COVID
NCT05375968
Postural tachycardia syndrome (POTS) affects ≈3 million young people, characterized by chronic presyncopal symptoms characterized by dizziness, lightheadedness, and orthostatic tachycardia that occur while standing. Across-sectional survey found that 25% of these patients complains that meals rich in carbohydrates are among the factors that further exacerbate POTS's symptoms and cause a myriad of gastrointestinal symptoms. The splanchnic circulation is the largest blood volume reservoir of the human body, storing ≈25% of the total blood volume and contributing to sudden, and large, fluctuations in the stroke volume (SV). The orthostatic changes in systemic hemodynamics are particularly magnified after meals, due to increased blood volume sequestration triggered by the release of gastrointestinal peptides with vasodilatory properties. The purpose of this study is to determine if the worsening orthostatic tachycardia and symptoms after glucose ingestion in POTS patients are due to a greater increase in splanchnic venous capacitance and excessive blood pooling on standing as compare to Healthy controls. The study will also determine if glucose-induced GIP secretion increases splanchnic venous capacitance, orthostatic tachycardia and worsening POTS postprandial symptoms. For this purpose subjects will be further randomized to either saline versus GIP(3-30)NH2 acute infusion, to measure the changes their splanchnic venous capacitance and superior mesenteric arterial flow before and after a 75-g oral glucose challenge during supine and 45-degree head-up tilt positions (orthostatic challenge) for up to 3 hours.
NCT05107635
The primary objective of this registry is to capture real-world safety and performance data on AtriCure devices used to ablate cardiac tissue when treating Inappropriate Sinus Tachycardia (IST) or Postural Tachycardia Syndrome (POTS). This is a retrospective and prospective, multicenter, US/OUS, observational data registry.
NCT00692471
We propose to use actigraphy (measured by activity watches) as a tool to quantify sleep disturbances in patients with orthostatic intolerance compared with healthy control subjects. In this pilot study, we will test the null hypothesis (Ho) that there are no differences in the sleep quality between patients with orthostatic intolerance and healthy control subjects.
NCT00581633
The investigators will test the hypothesis that patients with chronic orthostatic intolerance or postural orthostatic tachycardia syndrome (OI or POTS) will be unable to conserve urinary sodium as compared to healthy control subjects.
NCT02558972
Vasovagal syncope (VVS, simple faint) is the most common cause of transient loss of consciousness and represents the acute episodic form of orthostatic intolerance (OI). Postural tachycardia syndrome (POTS) is the common chronic form of OI. Both are defined by debilitating symptoms and signs while upright relieved by recumbency. Northera should therefore improve both sympathetic splanchnic arterial vasoconstriction and sympathetic splanchnic venoconstriction in POTS and VVS, and may represent an ideal drug to improve the orthostatic response in POTS and VVS.
NCT04170725
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.
NCT04140721
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.
NCT04943276
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.
NCT05409651
The mechanisms underlying POTS are not well understood. Though heterogeneous in nature, patients often present with symptoms that include fatigue, orthostatic lightheadedness and tachycardia, "brain fog", shortness of breath, and sleep disruption. The central mediator that links observations in disease entities similar to POTS is energy use and balance driven by mitochondrial health. Mitochondrial dysfunction (i.e. respiration defects, reactive oxygen species (ROS) generation, and structural abnormalities) are hallmarks of currently defined syndromes that resemble POTS symptomatology. Many patients with POTS have underlying immune system dysfunction, which, when treated, may improve the patient's overall health. Though autoimmunity has been demonstrated in POTS, overall immune dysregulation may be broader and include immune cell exhaustion and persistent inflammatory cytokine responses. Immune dysfunction including cellular exhaustion and persistent inflammation has been linked to mitochondrial function. Therefore, we hypothesize that a unifying feature of POTS results from latent or continued mitochondrial/immune dysfunction which then impacts multi-organ energy imbalance and immune homeostasis. Understanding and targeting mitochondria utilizing established, novel, and directed approaches including time-restricted eating (TRE) will help to unravel common etiologies and help us to better diagnose, manage, and treat POTS.
NCT04271878
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
NCT03253120
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)
NCT01550315
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.
NCT01210430
The investigators study will determine how often blood flow regulation abnormalities and abnormalities of sympathetic regulation produced by nitric oxide, angiotensin-II, and oxidative stress occur in POTS and the mechanism(s) of POTS in individual patients. Specific causes for POTS may vary from patient to patient. Patients will be compared to healthy control subjects. There is a treatment arm with a medication (losartan) that reduces the binding of angiotensin and increases NO. If the investigators know the specific biochemical mechanism the investigators may be able to offer further specific treatments to specific patients.
NCT03602482
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.
NCT02329548
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).
NCT00770484
The main limitation patients with orthostatic intolerance (OI, or postural tachycardia syndrome, POTS) have to exercise is related to their increase in heart rate when standing. Main pharmacological treatment today is aimed at reducing heart rate with the use of betablockers (propanolol), this theoretically could also improve their exercise capacity; if their heart rate do not increase as much with the medication, they could exercise more. In addition, it has been suggested that in healthy volunteers subjected to head down tilt for 2 weeks (situation that produces a "simulated" transient POTS-like state) a single bout of intense exercise can improve orthostatic tolerance the day after exercising. The mechanisms involved in such response are not that clear but could be an increase in plasma volume already diminished in POTS patients. It seems likely that the same could be true for POTS patients. The purpose of the present study are to pharmacologically improve the amount of exercise POTS patients can perform by reducing their baseline heart rate (specific aim 1) and to evaluate next day heart responses to an acute bout of intense exercise. Therefore, the specific aims of this study are: 1. To test the hypothesis that lowering heart rate response with propanolol will result in an increase in exercise capacity. 2. To test the hypothesis that a single bout of exercise will result in an improvement in orthostatic tolerance the day after exercising.