A device for treating atrial fibrillation includes a pad which houses the distal end of an electrode which is adapted to deliver a substantially uniform shock gradient to an atrial surface of a postoperative cardiac patient, if atrial fibrillation is detected. The device also includes a catheter for delivering anti-arrhythmic and/or anesthetic drugs to the pad. After a treatment period, the device may be removed by pulling the electrode and the pad, if the pad is not bioabsorbable, into the catheter and then pulling the catheter through the patient's chest wall.