Atrial antitachycardia pacing: do we still need to talk about it?

Abstract

Since first described in 1968,1 sick sinus syndrome (SSS) has become one of the most frequent indications for pacemaker implantation. Although in early days, the presence of atrial fibrillation (AF) limited the use of pacemakers in patients with SSS, nowadays pacemakers play an important role in the management of AF in patients with SSS. Highly sophisticated devices have been developed with increased Holter capabilities allowing continuous rhythm monitoring. Although the prevalence of AF prior to pacemaker implantation has been found in the range of 40–45%,2 AF detection during follow-up using pacemaker Holter data is reported in 50–65% of patients with SSS.3,4 In the Mode Selection Trial (MOST), pacemaker-detected paroxysmal AF was a strong independent predictor of stroke, death, and persistent AF, whereas symptoms as a clinical comparator could not reliably predict AF recurrence.4 The known limited success rate of drug therapy for rhythm control and the overwhelming number of pacemaker patients with paroxysmal AF prompted interest in using pacing therapy to treat AF. Therapy options developed included alternative single-site atrial pacing, multisite atrial pacing, pacing algorithms to prevent AF by increasing the amount of atrial pacing suppressing triggers of AF, and atrial antitachycardia pacing (ATP) to terminate AF. Many clinical trials have been conducted over the past 10 years studying the efficacy of pacing algorithms for AF prevention and termination. The present paper by Gillis et al. 5 reports the first long-term data on atrial ATP. Neither ATP alone nor ATP in combination with preventive pacing algorithms could successfully suppress atrial tachycardia (AT)/AF during a follow-up period of 3 years. The trial was early terminated due to phasing out of the AT500/501 pacemaker and study results may have been underpowered to detect any differences. However, the results correlate well with other ATP studies like … *Corresponding author. Tel: +49 89 9270 2071, Fax: +49 89 9270 2683, Email: ellen.hoffmann{at}klinikum-muenchen.de