Postural Tachycardia Syndrome

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.

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.

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

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.

This study is being conducted to see how people with Postural tachycardia syndrome (POTS) make sense of the things they see. The information may help doctors to learn more about how the different parts of people's brains communicate.

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.

This single-center study aims to evaluate both immediate and long-term outcomes of stellate ganglion block (SGB) in a cohort of rigorously phenotyped patients with Postural Tachycardia Syndrome (POTS). By assessing the effects of SGB, this study seeks to determine its viability as an intervention for symptom control in POTS.

We examine patients with different autonomic neuropathies and Ehlers Danlos syndromes compared to healthy controls at three different points over time (baseline, after 3 months and after 1.5 years) to gain knowledge about the course of this disease and understand its pathophysiology, with a focus on Small Fiber neuropathy. Moreover we will validate the german version of the Malmö POTS Score and establish an easy diagnostic scheme for patients in outpatient care.

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 10 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.