Effect of taVNS on Heart Rate in Persistent Atrial Fibrillation

The goal of this clinical trial is to investigate the effects of non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) in patients with persistent atrial fibrillation. taVNS is a treatment through which a small electrical current is applied to a specific location of the left ear. The main question to answer is whether taVNS will reduce the heart rate in patients with persistent atrial fibrillation. After appropriate training, participants will self-administer taVNS for 30 minutes every day for two weeks. During one of the two weeks (randomized order), the clip electrode, delivering the electrical current will be attached to the cymba conchae of the left ear, while during the other week the clip electrode will be attached to the lobule of the left ear. During both weeks, the electrocardiogram (ECG) will be monitored continuously through a small ECG patch that is placed on the chest. Participants will meet with the investigators at the beginning of the study, after 7 days and at the end of the study (after 14 days). Researchers will compare the ECG obtained during the two weeks and evaluate if the heart rate differs between the two study weeks.