Parasympathetic stimulation for treating atrial arrhythmia and heart failure
Apparatus is provided that includes an electrode device, adapted to be coupled to a vagus nerve of a subject, and a control unit, adapted to drive the electrode device to apply to the vagus nerve a current that reduces heart rate variability of the subject. Also provided is a method comprising applying to a vagus nerve of a subject a current that reduces heart rate variability of the subject.
1. A method for treating a subject, comprising:
identifying that the subject suffers from heart failure; and
treating the heart failure by:
determining that a heart rate of the subject is within a normal heart-rate range of the subject; and
responsively to the determination, applying, only when the heart rate is within the normal heart-rate range of the subject, a current to a site of the subject selected from the group consisting of: a vagus nerve and an epicardial fat pad.
2. The method according to claim 1 , wherein applying the current comprises:
applying current in respective pulse bursts in each of a plurality of cardiac cycles of the subject; and
synchronizing the bursts with the cardiac cycles.
3. The method according to claim 2 , wherein applying the current comprises setting a control parameter of a feedback algorithm governing the current application to be a number of pulses per each one of the bursts.
4. The method according to claim 3 , wherein the feedback algorithm includes an integral feedback algorithm that has inputs including the heart rate of the subject and the threshold value.
5. The method according to claim 1 , wherein applying the current comprises cycling between “on” periods, during which the current is applied, and “off” periods, during which the current is withheld.
6. The method according to claim 1 , wherein applying the current comprises configuring the current using fixed programmable parameters that do not vary in response to any feedback.