RecruitingDevice studyBiomarker-Guided Optimization of Transcutaneous Vagal Stimulation for Atrial (BiG tVNS-AF)This proposal aims to determine the effects of tVNS on autonomic tone, atrial substrate and neuromodulators in patients with paroxysmal atrial fibrillation (AF), investigate the chronic effects of optimal tVNS on AF burden in patients with paroxysmal AF over a 6-month period, compared with sham stimulation, and identify physiological and biochemical markers of response to chronic tVNS.