Effects of auricular vagal neuromodulation therapy combined with slow-paced diaphragmatic breathing in individuals with postural tachycardia syndrome: a randomised controlled trial protocol

Introduction Postural orthostatic tachycardia syndrome (POTS) is a multifactorial disorder of the autonomic nervous system characterised by an excessive increase in heart rate (HR) on standing and a wide range of debilitating symptoms, including fatigue, exercise intolerance, cognitive impairment and a high prevalence of depression, anxiety and sleep disturbances. Conventional pharmacological strategies often offer limited relief and do not sufficiently address non-cardiac symptoms.

Auricular vagal neuromodulation therapy (AVNT) and slow-paced diaphragmatic breathing (SDB) have each demonstrated promise in modulating autonomic function and alleviating symptom burden but their combined effects in POTS have yet to be investigated. Methods and analysis This single-centre, partially blinded, 12-week randomised controlled trial will be conducted at the Medical University of Vienna.

A total of 100 participants with confirmed POTS will be recruited, with 25 per group. This sample size is already accounting for an anticipated 30% dropout rate.