Device-Specific Responses to Pacemaker-Mediated Arrhythmia in Patients With Prolonged Ventriculoatrial Conduction: A...

Pacemaker-mediated tachycardia (PMT) triggered by prolonged ventriculoatrial conduction (VAC) can be challenging to detect and terminate. The behavior of device-specific anti-PMT algorithms in such scenarios, as well as the potential utility of DDI mode as an alternative strategy, remain to be fully elucidated.

Five dual-chamber pacemakers from Abbott, BIOTRONIK, Boston Scientific, Medtronic, and MicroPort CRM were tested using an electrophysiological simulator under VAC times of 450 ms and 550 ms. We assessed (1) PMT detection and termination in DDD mode, (2) atrial sensing within the post-ventricular atrial refractory period (PVARP) in DDI mode, and (3) the timing adjustment of atrial pacing after retrograde atrial sensing.

At VAC 450 ms, all devices except Medtronic detected PMT. Only Abbott terminated PMT at 550 ms with a shortened AV delay. Four devices detected atrial events within PVARP at 450 ms, whereas only BIOTRONIK did so at 550 ms. Among these, BIOTRONIK, Boston Scientific, and Medtronic adapted atrial pacing timing following atrial sensing within the refractory period, while Abbott did not, resulting in repetitive nonreentrant ventriculoatrial synchrony.

Anti-PMT performance varies markedly among manufacturers. Devices featuring a longer PVARP and an atrial pacing delay algorithm provide superior protection against pacemaker-mediated arrhythmias during prolonged VAC. These findings underscore the importance of individualized pacemaker selection and careful programming.