Parasympathetic stimulation for prevention and treatment of atrial fibrillation

1. A method comprising:

identifying that a subject is at risk of suffering from atrial fibrillation (AF); and

responsively to the identifying, reducing a risk of an occurrence of an episode of the AF by:

detecting normal sinus rhythm (NSR) of the subject,

during the detected NSR, applying an electrical current to a site of the subject containing parasympathetic nervous tissue, and

configuring the current to stimulate the parasympathetic nervous tissue in the site,

wherein applying the current comprises configuring the current so as to minimize an effect of the applying of the current on a heart rate of the subject.

2. The method according to claim 1 , wherein the site is selected from the group consisting of: a vagus nerve, an epicardial fat pad, a sinoatrial (SA) node fat pad, an atrioventricular (AV) node fat pad, a pulmonary vein, a carotid artery, a carotid sinus, a coronary sinus, a vena cava vein, a jugular vein, an azygos vein, an innominate vein, and a subclavian vein, and wherein applying the current comprises applying the current to the selected site.

3. The method according to claim 1 , wherein applying the current comprises:

sensing the occurrence of the episode of the AF; and

responsively to the sensing, withholding applying the current during a period having a duration of at least one minute.

4. The method according to claim 1 , wherein applying the current comprises:

setting a threshold heart rate;

sensing the heart rate of the subject;

comparing the sensed heart rate with the threshold heart rate; and

applying the current upon finding that the sensed heart rate is less than the threshold heart rate.