This study is an investigator-initiated, monocentric, randomised, controlled and blinded trial. Patients with persistent atrial fibrillation and planned electrical cardioversion will be included. The participants are randomised to one of two groups - the verum-group or the sham-group. Both groups receive a dedicated stimulation device that stimulates transcutaneously the Ramus auricularis of the Nervus vagus at the area of the Tragus. The verum-group will receive an effective stimulation and the sham-group an ineffective one. The aim of this trial is to evaluate whether this stimulation could reduce the recurrence of atrial fibrillation or not. Therefore daily stimulation of at least one hour will be performed for overall three months. After that period the stimulation will be withdrawn and both groups will be compared. Then, after another three months without stimulation both groups will be compared again to evaluate if a potential effect of the initial stimulation persists.
The goal of this clinical trial is to answer the question whether a transcutaneous stimulation of a certain nerve (Nervus vagus) with a dedicated device reduces the recurrence of the heart rhythm disorder atrial fibrillation.~Participants will receive a dedicated nerval stimulation device and will treat themselves on a daily basis for at least an hour per day. Treatment will last for 3 months. Researchers will compare this group with a similar group that uses an ineffective device. Both researcher and patients will be blinded so they do not know which device they will be using.