Autoimmune Basis for Postural Tachycardia Syndrome

Not Applicable

Recruiting

• Conditions: Postural Tachycardia Syndrome
• Interventions: Device: Vagal stimulation; Device: Sham stimulation

• Registration Number: NCT05043051
• Lead Sponsor: University of Oklahoma

Brief Summary

The purpose of this study is to test the hypothesis that an antibody-mediated autoimmune reaction will cause symptoms of autonomic dysfunction in some patients with postural tachycardia syndrome (POTS). The investigators further hypothesize that electrical stimulation of the vagus nerve will improve POTS symptoms, autoimmunity and inflammation.

Detailed Description

The present study is designed to test the hypothesis that muscarinic autoantibody-mediated parasympathetic dysfunction contributes to the pathogenesis of POTS, and that parasympathetic (vagal) stimulation improves POTS symptoms, autoimmunity and inflammation.

Define and determine the prevalence, burden, and clinical significance of muscarinic autoantibodies in a well-phenotyped cohort of POTS patients with and without gastroparesis and a matched cohort of healthy control subjects.

Evaluate the impact of vagal stimulation on antibody suppression, inflammatory inhibition, and symptom improvement in POTS patients. Non-invasive transcutaneous stimulation of the auricular branch of the vagus nerve (tragus stimulation) will be used to increase parasympathetic activity.

Study Timeline

• Study First Submitted: 2021-08-27
• Study First Submitted QC: 2021-09-08
• Study First Posted: 2021-09-13
• Study Start: 2022-01-14
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-24
• Last Update Posted: 2025-03-25
• Primary Completion: 2026-02-28
• Study Completion: 2026-07-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 80

Inclusion Criteria

• 18-80 years old, female or male
• Either healthy control or individual with postural tachycardia syndrome (POTS) defined as heart rate increase >30 bpm from supine within 10 min of standing, in the absence of orthostatic hypotension (>20/10 mmHg fall in blood pressure), with chronic symptoms (>6 months), and in the absence of other acute cause of orthostatic tachycardia
• Able and willing to provide informed consent
• Understand and be able to comply with the study procedures and restrictions

Exclusion Criteria

• Hypertension (>150 mmHg systolic and >100 mmHg diastolic) based on history or findings at screening
• Orthostatic hypotension (consistent drop in blood pressure >20/10 mmHg with 10 min of standing)
• Cardiovascular disease, such as myocardial infarction within 6 months
• History or presence of significant immunological or hematological disorders
• History of vagotomy
• Currently pregnant women or women planning on becoming pregnant ≤ 3 months
• Inability to comply with the protocol
• Patients with active implants (such as a cardiac pacemaker, or a cochlear implant)

Healthy control subjects will be healthy, non-smoking and on no chronic medications at the time of the study. Healthy control subjects will be group-matched to the POTS patients for age and gender.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Vagal stimulation	Vagal stimulation	Vagal stimulation will be given at 20 Hz for 1 hour daily with the bipolar electrode attached to the tragus for 2 months.
Sham stimulation	Sham stimulation	Sham stimulation will be given at 20 Hz for 1 hour daily with the bipolar electrode attached to the earlobe for 2 months.

Primary Outcome Measures

Name	Time	Method
Heart rate variability	5 minute	Average of heart rate variability during the posture test

Trial Locations

Locations (1)

Oklahoma Clinical and Translational Science Institute; 🇺🇸 Oklahoma City, Oklahoma, United States