The Role of Electrophysiologic Study in Device Selection for Leadless Atrial Pacing.

The AVEIR DR (Abbott Medical) was the first dual-chamber leadless pacing system approved by the US Food and Drug Administration. Many patients with sinus node dysfunction have physiologically normal atrioventricular conduction, so an atrial-only pacing system may be appropriate for them. Three patients with symptomatic sinus node dysfunction underwent device implantation with electrophysiologic study, including incremental atrial pacing until loss of 1:1 atrioventricular conduction (atrioventricular Wenckebach cycle length) and His-ventricular interval measurement. If the atrioventricular Wenckebach cycle length was no more than 400 milliseconds and the His-ventricular interval measurement was no more than 55 milliseconds, single-chamber atrial implantation was deemed appropriate. Each patient displayed a different response to atrioventricular conduction testing, demonstrating how electrophysiologic study before device implantation may identify patients for whom atrial-only pacing is not appropriate.