Clinical Research Directory

Transdermal Vagal Stimulation for POTS

Some patients experience high heart rates and symptoms of light-headedness, fatigue, headache during standing despite well maintained blood pressure. These patient are disabled and can't be in upright position for a longer time. The purpose of this study is to test whether electrical stimulation of a nerve through a skin of the ear may improve heart rate response and reduce disabling symptoms.

Auricular Vagal Nerve Stimulation for Hypermobile Ehlers-Danlos Syndrome

Hypermobile Ehlers-Danlos Syndrome (hEDS) is a connective tissue disorder characterized by hyperextensible skin, joint hypermobility and additional connective tissue manifestations. For unclear reasons, hEDS is associated with many gastrointestinal (GI) and autonomic nervous system (ANS) complaints such as postural orthostatic tachycardia syndrome (POTS). This study will address the clinical relationship between hEDS/Hypermobile Spectrum Disorders and autonomic regulation and see if there is a benefit of two forms of non-invasive vagal nerve stimulation therapies to reduce GI symptoms in hEDS and POTS. The study will also investigate plausible effects of these nerve stimulation therapies on gastric function and autonomic signaling.

Evaluating the Prevalence of Acute Hepatic Porphyria in Postural Tachycardia Syndrome

Postural Tachycardia Syndrome (POTS) is the most common autonomic disorder and is estimated to affect 3,000,000 individuals in the United States, with 80-85% of patients being women. The condition is characterized by a rapid increase in heart rate (HR) that occurs on standing, and chronic symptoms of cerebral hypoperfusion leading to lightheadedness, dizziness, and blurred vision. The acute hepatic porphyrias(AHP)are among the diseases that present with autonomic cardiovascular(tachycardia)and neurovisceral symptoms (abdominal pain) among others; they present with acute exacerbations Given that there is available treatment for AHP that change the natural progression of the disease, study focuses to investigate the occurrence of AHP in POTS and determine the clinical and neuro-hormonal characteristic of the POTS subgroup that will likely benefit from AHP screening. This study has one visit that involves, answering some questionnaires, coming to the lab for blood work, genetic testing, and some autonomic function tests. About 50 people will take part in this study.

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.

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.

Assessment of Antibodies and Inflammatory Markers in Postural Tachycardia Syndrome

In this pilot study, the investigators will test the hypothesis that patients with postural tachycardia syndrome will have an elevated percentage of functional antibodies to adrenergic receptors compared with control subjects without POTS. The investigators further hypothesize that the percentage of POTS patients with antibodies will be higher in those patients with a viral infection at the onset of their illness than in those patients with other or undefined illness onsets.

Pathophysiology of Orthostatic Intolerance

The purpose of this study is to describe the mechanism of orthostatic intolerance, relying on cardiovascular physiological studies. The syndrome is of undetermined etiology, but the syndrome causes impairment of a number of young adults, females more than males, with symptoms of tachycardia, fatigue, lightheadedness, palpitations, blurred vision, chest discomfort, difficulty concentrating, and dizziness with the upright posture. It is believed that many different pathophysiological processes can give rise to this disorder.

Phenotyping of Postural Orthostatic Tachycardia Syndrome (POTS)

This is an observational study to deeply phenotype the disorder of POTS using multiple testing modalities.

The Long COVID-19 Wearable Device Study

To further characterize Long COVID-19 by collecting data from individuals who already own wearable devices or are provided with a wearable device along with basic and enhanced educational materials to determine if both can improve Long COVID-19 symptom management and post-exertional malaise.

Physical Training in Patients With POTS After Covid-19

Covid-19 has the potential to affect physical, cognitive and psychological functions in multiple ways. It has been clear that a significant proportion of patients with Covid-19 develop long-term symptoms. The term post-acute Covid-19 syndrome (PACS) is now used to describe the wide range of prolonged symptoms following the infection. Patients may need specialized rehabilitation to be able to meet the complex symptoms and problems that may arise. A more specific syndrome that seems to occur more frequently than expected in the group of non-hospitalized patients who have had Covid-19 is the postural orthostatic tachycardia syndrome (POTS). To evaluate the effects of physical training in patients with POTS after Covid-19 a single subject design will be used (the patient is their own control). Inidividual semistructured interviews will be performed to explore and describe the patients´ experiences of the rehabilitation intervention. Participants: Patients diagnosed with POTS after Covid-19 (N=30) will be included. Procedure and outcomes: The primary outcomes are physical activity and health-related quality of life. Secondary outcomes are: physical capacity, active standing test, Malmö-POTS-questionnaire, Anxiety and depression, fatigue, self-reported outcome measure of physical function and work ability. Initially measurements will be performed several times during a period of 2-4 weeks to obtain a baseline before the intervention starts. Then the included participants will undergo a specially designed physical training program that will be performed 3 times /week during a period of 12 weeks. The intervention of physical training will consist of different exercises to enhance muscle strength and endurance. The intervention will be individually adjusted with a progression in dose, intensity, and position. The exercise is based on a program used in a previous study. Measurements will then be repeated after completion of the intervention period. A qualitative approach, with semistructured interviews, will be used to explore the patients´ experiences of the intervention, after commence of the interventional trial.

NC Testing in LC & POTS

Patients with Postural Orthostatic Tachycardia Syndrome (POTS) and Post-Acute Sequelae of COVID (PASC, or "Long COVID") experience cognitive dysfunction. The investigators will test the hypothesis that 999 mL of IV saline will improve cognitive function in patients with POTS and Long COVID compared to placebo (50 mL of saline).

Effects of Individual Tailored Physical Exercise in Patients With POTS After COVID-19 - a Randomized Controlled Study

Covid-19 has the potential to affect physical, cognitive and psychological functions in multiple ways. It has been clear that a significant proportion of patients with Covid-19 develop long-term symptoms. The term post COVID-19 condition (defined by WHO) is used to describe the wide range of prolonged symptoms following the infection. Patients may need specialized rehabilitation to be able to meet the complex symptoms and problems that may arise. A more specific syndrome that seems to occur more frequently than expected in the group of non-hospitalized patients with post COVID-19 condition is the postural orthostatic tachycardia syndrome (POTS). A randomized controlled design will be used to evaluate the effects of individual tailored physical exercise in patients with POTS after Covid-19. Participants: Adults (\>18 years) with post COVID-19 condition and diagnosed with POTS (n=60) will be included. Exclusion criteria: known pregnancy, cancer, already ongoing individual physical exercise (specific for POTS), or not able to perform measurements and/or intervention. Procedure and outcomes: The primary outcomes are objectively measured time in upright position and health-related quality of life. Secondary outcomes are: physical activity, physical capacity, work ability and disease specific symptoms measured with tests and questionnaires. Prior to randomization baseline measurements will be performed, aswell as after 16 weeks, 6 months and 12 months. Intervention: Participants randomized to intervention will receive standard care and undergo a individually designed physical exercise program during 16 weeks, supervised and guided by a physiotherapist. The intervention will consist of different exercises to enhance muscle strength and endurance. Progression will be according to a program (based on previous feasibility studie) but should be halted if post exertional malaise (PEM) or other problems occur. Controls: Participants randomized to control will receive standard care during 16 weeks. Measurements of both groups (control and intervention) will be repeated after completion of a period of 16 weeks.

Postural Sway and Counterpressure Maneuvers for Pediatric Syncope

The investigators are interested in whether discrete counterpressure maneuvers, or muscle movements in the lower body, will boost blood pressure and cardiovascular control in children who faint. We will record cardiovascular responses to maneuvers of exaggerated sway, leg crossing, crouching, and gluteal muscle tensing in children who faint (N=20), as well as their height, weight, muscularity, and pubertal (Tanner) stage. Autonomic cardiovascular control will be measured using a Valsalva manoeuvre (expiration against a closed airway for 20 seconds) and a supine-stand test. The primary outcomes are noninvasive measures of cardiovascular responses to the maneuvers (blood pressure, cerebral blood flow, and stroke volume (volume of blood pumped per heartbeat). Comparisons will be made across levels of sex, diagnosis, Tanner stage, muscularity, height, and degree of autonomic control.

Paediatric Syncope in the Emergency Department

The investigators will assess the efficacy of clinically recommended counterpressure maneuvers (CPM) in preventing syncope for paediatric patients. Participants presenting to the emergency department (ED) will first provide written informed consent. In stage I, they will be asked to complete a brief survey documenting the presentation of their syncopal episode, and any prodromal symptoms they experienced. Participants that consent to the second stage of the study will either receive usual care (control arm) or training in counter pressure maneuvers alongside usual care (intervention arm; leg crossing, bending, arm tensing). These patients will be followed for one years time, and will be asked to complete monthly surveys detailing their syncopal and presyncopal recurrence. Medical records will be accessed over the duration of the study to identify any changes in medical diagnosis.

CAlgary SAlt for POTS

Many patients with postural orthostatic tachycardia syndrome (POTS) have decreased plasma volume. Current POTS guidelines recommend \~10 g of salt and 2-3 L of fluid per day. Despite this recommendation, there is no long term data evaluating the use of salt in POTS. This randomized, placebo-controlled cross-over trial will evaluate a high salt diet, compared to a normal salt diet over a period of 3 months. Participants will complete 3 in lab evaluations including autonomic function testing, tilt table testing, blood volume and urine sodium evaluation, plasma catecholamine measurements and and cytokine measurements.

Compression Garments in the Community With POTS

Compression Garments are a commonly prescribed treatment in Postural Orthostatic Tachycardia Syndrome (POTS). The effectiveness of a proof-of-concept compression garment has been demonstrated in an acute laboratory setting. It is not known if commercially available compression garments that participants wear in their every day lives are effective at improving heart rate and reducing symptoms in POTS. This trial will evaluate the use of commercially available waist-high and abdominal compression garments in adults diagnosed with POTS in a community setting.

Low Dose Naltrexone Use in Patients With POTS

Many patients with Postural Orthostatic Tachycardia Syndrome (POTS) experience debilitating fatigue and this significantly impacts their daily lives. Unfortunately, there are no treatments to help POTS patients with their fatigue. One medication, called low dose naltrexone (LDN), has been tested as a treatment for fatigue in other medical conditions. In this other research, LDN helped patients feel less fatigue. Other research studies have shown that LDN can help reduce markers of inflammation called cytokines. Reducing these cytokines could help reduce symptoms as well. There have been no research studies testing LDN in POTS to date. We are planning to do a research study to test LDN as a treatment to see if it helps POTS patients feel less fatigue.