Atrioventricular Synchrony Maintained by a Dual-Chamber Leadless Pacemaker in Real-World Conditions

Abstract Background and Aims A dual-chamber leadless pacemaker (LP) system relies on a beat-to-beat, wireless, implant-to-implant (i2iTM) communication between implanted devices in the right atrium and right ventricle (A-to-V and V-to-A). Atrioventricular (AV) synchrony was evaluated during an ambulatory 24-hour period of daily living. Methods A prospective, single-arm, multi-center clinical study (ClinicalTrials.gov identifier NCT05252702) evaluated the overall safety and performance of the dual-chamber LPs in patients with standard indications for dual-chamber pacing. Following the 3-month visit, eligible patients wore 12-lead Holter monitors for 24 hours while resuming the activities of daily living while under clinically driven programmed settings. LP diagnostic data were interrogated when patients returned to the clinic. An independent Holter core laboratory adjudicated the proportion of synchronous beats (PR intervals within paced and sensed AV delay bounds). Relationships between AV synchrony and i2i communication success rate, implant indication, heart rate, and AV event type were evaluated. Results Among 47 analyzable patients, mean AV synchrony was achieved in 96.7% of beats, exceeding mean A-to-V and V-to-A transmission success rates of 93.4% and 92.1%, respectively. There were no significant differences in AV synchrony between sinus node and AV block patients. Across all AV paced/sensed cycle combinations and heart rate ranges (including 100 bpm), AV synchrony was sustained 90% in an ambulatory real-world setting. Conclusions A dual-chamber leadless pacing system demonstrated 96% overall AV synchrony for a 24-hour period of daily living while programmed to clinically appropriate settings, thus showing that true dual-chamber DDD(R) pacing can be maintained in a real-world environment.