Clinical utilization of current pacemakers for left bundle branch area pacing
M Sprowls, E Johnson, K Ryu, L Sabet, D NairAbstract
Introduction
Left bundle branch area pacing (LBBAP) implantation is increasingly adopted in pacemaker patients since it leverages the physiological conduction pathway for ventricular stimulation. Despite the increased prevalence of LBBAP implantation, detailed data on pacemaker performance and programming remains limited.
Methods
Retrospective analysis of data from pacemaker devices through September 2024 connected to leads implanted in LBBAP was performed. Pacing capture threshold (PCT) and sensed R-wave amplitude (RWA) from the leads implanted in the LBBA was analyzed for initial (within 30 days of implant), 3-month (±14 days), and 6-month (±14 days) remote follow-ups. PCTs were measured at 0.4-0.5ms pulse width using AutoCapture or RV CapConfirm. Pacemaker/lead type, programmable pacing/sensing parameters, and indication for implant were analyzed.
Results
Data from 2,894 VR (7%), DR (83%), and CRT-P (10%) devices were analyzed. The leads implanted in the LBBA were predominately Tendril STS 2088TC (77% of devices). Bipolar/unipolar pacing was used in 81%/19% of devices, respectively. Nominal ventricular sensing (2mV, fixed sensitivity) was programmed in 87% of devices and AutoSense in 10%. In devices with the feature turned on at any point, ventricular AutoCapture, CapConfirm, and AutoSense remained activated chronically in 93.5% (1312/1403), 97.0% (130/134), and 96.5% (279/289) of devices. Pacing output was ≤2.5V in 71% (1018/1440) of devices with AutoCapture/CapConfirm programmed off. Sensed and paced AV delays were reprogrammed to non-nominal values at implant in 49.0% and 59.1% of devices where ventricular intrinsic preference was not activated. Sensed/paced AV delay was programmed to nominal ±50 ms in 85%/93%, respectively, or to the extremum setting in 0.8%/1.1% of devices, respectively. LBBA pacing burden was 76±37%, 63±42%, and 32±40% for patients with AV block (N=938), atrial fibrillation (N=364), and sinus node dysfunction (N=304) respectively. PCT and RWA measured automatically by devices are presented in Figure 1 with comparison to data from MELOS (Jastrzębski 2022). AV delays at most recent remote follow-up are presented in figure 2.
Conclusion
Commercially available pacemakers demonstrated satisfactory pacing/sensing performance and programmability when used for LBBAP in a real-world dataset.