Optimizing mechanically sensed atrial tracking in patients with atrioventricular-synchronous leadless pacemakers: A single-center experience

Abstract

Background Atrioventricular (AV)-synchronous single-chamber leadless pacing using a mechanical atrial sensing algorithm produced high AV synchrony in clinical trials, but clinical practice experience with these devices has not yet been described. Objective To describe pacing outcomes and programming changes with AV-synchronous leadless pacemakers in clinical practice. Methods Consecutive patients without persistent atrial fibrillation who received an AV-synchronous leadless pacemaker and completed follow-up between February 2020 and April 2021 were included. We evaluated tracking index (atrial mechanical sense followed by ventricular pace [AM-VP] divided by total VP), total AV synchrony (sum of AM-ventricular sense [AM-VS], AM-VP, and AV conduction mode switch), use of programming optimization, and improvement in AV synchrony after optimization. Results Fifty patients met the inclusion criteria. Mean age was 69 ± 16.8 years, 24 (48%) were women, 24 (48%) had complete heart block, and 17 (34%) required ≥50% pacing. Mean tracking index was 41% ± 34%. Thirty-five patients (70%) received ≥1 programming change. In 36 patients with 2 follow-up visits, tracking improved by +9% ± 28% ( P value for improvement = .09) and +18% ± 19% ( P = .02) among 15 patients with complete heart block. Average total AV synchrony increased from 89% [67%, 99%] to 93% [78%, 100%] in all patients ( P = .22), from 86% [52%, 98%] to 97% [82%, 99%] in those with complete heart block ( P = .04), and from 73% [52%, 80%] to 78% [70%, 85%] in those with ≥50% pacing ( P = .09). Conclusion In patients with AV-synchronous leadless pacemakers, programming changes are frequent and are associated with increased atrial tracking and increased AV synchrony in patients with complete heart block.

A real‐world experience of atrioventricular synchronous pacing with leadless ventricular pacemakers

“…greater than 70% AV synchrony. 20 AF was present in 26% of their study sample, and a higher VP burden was associated with lower AV synchrony similar to our results. It makes intuitive sense that when patients are in AF, the ability of the device to sense atrial mechanical activity will be unreliable.…”

“…16,17 Apart from a recent report by Arps et al and a case series reporting troubleshooting scenarios, data regarding the realworld experience of this novel system is lacking. [18][19][20] We sought to define the characteristics of patients undergoing Micra TM -AV implants at the Mayo Clinic, common troubleshooting issues, and the implant outcomes to understand appropriate patient selection and management strategies in these patients.…”

“…In the prospective MARVEL 2 (Micra TM Atrial tRacking using a Ventricular accELerometer 2) study, over 90% of patients with Micra TM ‐AV and the programmed VDD algorithm achieved AV synchrony 16,17 . Apart from a recent report by Arps et al and a case series reporting troubleshooting scenarios, data regarding the real‐world experience of this novel system is lacking 18–20 . We sought to define the characteristics of patients undergoing Micra TM ‐AV implants at the Mayo Clinic, common troubleshooting issues, and the implant outcomes to understand appropriate patient selection and management strategies in these patients.…”

Symphony to leadless pacing—An Ode to Joy

“…Most importantly, their data confirms and is in line with recent reports, 8,9 that the success in achieving AV synchrony in a real-world setting may be lower than the MARVEL 2 clinical trial. The results also emphasize the importance of active programming changes which can significantly improve AV synchrony following an optimization postimplantation.…”

“…Critical programming changes made by performing a manual atrial mechanical (MAM) test while disabling the features that automatically affect these include adjusting the PVAB, A3/A4 windows, and A3/A4 thresholds, and turning off the AV conduction mode (VVI+) in those with complete heart block and escape >40 bpm. The authors and others 8,9 have identified helpful examples of troubleshooting these interval timings and thresholds for optimizing AV synchrony, which an implanter must be familiar with to successfully manage patients with leadless AV synchronous devices. Critically, while performing a MAM test, a key prerequisite for successful interpretation of device tracings is the inclusion of an optimal electrocardiogram tracing.…”