Novel Pacemaker-Mediated Arrhythmia Without Ventriculoatrial Conduction Can Induce Atrial Fibrillation

Abstract

Cardiovascular implantable electronic devices can initiate and sustain pacemaker-mediated arrhythmias. Endless loop tachycardia and repetitive non-re-entrant ventriculoatrial synchrony (RNRVAS) are well-described examples of pacemaker-mediated arrhythmias. However, such arrhythmias only occur in the presence of ventriculoatrial conduction. We identified a novel pacemaker-mediated arrhythmia that closely mimics RNRVAS but in the absence of ventriculoatrial conduction. We identified these arrhythmias in 9 patients, all with a St. Jude Medical/Abbott device, recorded as inappropriate mode-switch episodes by a device algorithm that includes paced events in the atrial counter. This report describes the mechanism, discusses clinical implications, and outlines programming options to eliminate this pseudo-RNRVAS.

Keywords: atrial fibrillation; dual-chamber pacemaker; inappropriate mode-switch; novel arrhythmia; pacemaker-mediated arrhythmia; repetitive non-re-entrant ventriculoatrial synchrony.