Transdermal Vagal Stimulation for POTS

Study Overview
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Brief Summary
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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.

Detailed Description
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Background Postural Tachycardia Syndrome (POTS) is a syndrome characterized by disabling symptoms of inadequate cerebral perfusion on assuming the upright posture, including light-headedness, fatigue, palpitations, altered mentation, headache, nausea, presyncope, and occasionally syncope. POTS is characterized by an excessive increase in heart rate and exaggerated increase in plasma catecholamine levels on standing in the absence of a blood pressure fall. These disabling symptoms persist for more than six months. Objective The objective of this study is to study the effect of vagal stimulation on heart rate modulation during supine and upright posture as a treatment modality for patients with POTS.

Official Title
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Transdermal Vagal Stimulation for the Treatment of Postural Tachycardia Syndrome

Conditions
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Postural Orthostatic Tachycardia Syndrome

Intervention / Treatment
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* Other: Stimulation
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Non-smoking patients who qualify with the criteria of idiopathic postural tachycardia syndrome will be studied. The criteria are: an increase of heart rate of 30 beats/minute or an upright heart rate of >= 120 bpm, and chronic problems of symptoms during upright posture for at least 6 month. Subjects must also be able to safely withdrawn from medications that influence heart rate, blood pressure, and hormone levels that regulate blood pressure. The age limit is 18-75 years. Exclusion Criteria: Patients that have other major medical problems, such as cancer or heart disease are excluded because the influence of that diagnosis on the symptoms is not known. Pregnancy.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Vagal Stimulation First<br>Vagal stimulation to improve upright heart rate modulation and symptoms is given on first tilt study day. Placebo stimulation with ineffective low amplitude and frequency (sham intervention) is given on second tilt study. | Other: Stimulation<br>* Application of current to skin above auricular branch of vagal nerve to modulate heart rate and symptoms<br>Other: Placebo<br>* Application of low intensive current or frequency to skin above auricular branch of vagal nerve as sham intervention<br>|
| Placebo Comparator: Placebo First<br>Placebo stimulation with ineffective low amplitude and frequency (sham intervention) is given on first tilt study day. Vagal stimulation to improve upright heart rate modulation and symptoms is given on second tilt study day. | Other: Stimulation<br>* Application of current to skin above auricular branch of vagal nerve to modulate heart rate and symptoms<br>Other: Placebo<br>* Application of low intensive current or frequency to skin above auricular branch of vagal nerve as sham intervention<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart Rate (average of 1 minute) | Upright heart rate and heart rate change from supine measured during graded tilt with 15 degrees increments each 5 minutes till 30 min of 75 degrees or abort. | [-5,0,5,10,15,20,..,50 min] relative time from tilt | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Orthostatic Symptoms (Subjective analog symptoms scale (0-100) | Subjective analog symptoms scale (0-100) | [-5,0,5,10,15,20,..,50 min] relative time from tilt | 
| Orthostatic Tolerance (Maximal tolerated time in upright position) | Maximal tolerated time in upright position | [0-50 min] relative time from tilt | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Postural Orthostatic Tachycardia Syndrome, POTS, Vagal Stimulation