Clinical experience with the implantable atrial defibrillator (atrioverter) in patients with atrial fibrillation

Due to the limited efficacy of drug therapy in atrial fibrillation and the high rate of recurrence, strong efforts were made to find non-pharmacologic al strategies. For three years now, the implantable atrial defibrillator Me trix(TM) from InControl has been available as an alternative therapy. From October 1995 to the present the atrial defibrillator was implanted in 179 p atients worldwide. The sensitivity of the system and its algorithms to dete ct atrial fibrillation is 90 %; the specifity to detect sinus rhythm 100 %. In 121 of 179 patients, 748 episodes of spontaneous atrial fibrillation we re treated with 2.4 shocks per episode. No proarrhythmic event or stroke wa s seen. A cardioversion to sinus rhythm could be achieved in 95 % of patien ts; the overall clinical success rate was 88 %. In 7 % of all patients, ear ly recurrence of atrial fibrillation (ERAF) occurred that could not be conv erted into stable sinus rhythm after further cardioversions and antiarrhyth mic therapy. In 4.1 % there were lead-related complications, in 3 patients the device had to be explanted because of ineffective therapy, and in 3 pat ients the device had to be changed because of loss of telemetry or early de pletion of battery. In 8 patients, postoperative complications were seen (i nfections, pneumothorax and thrombosis of the subclavian vein). Overall, th e implantable atrial defibrillator Metrix(TM) is an effective and safe alte rnative in treating atrial fibrillation.