PO-03-013 ELECTRO-ANATOMICAL CHARACTERIZATION OF LEADLESS LEFT BUNDLE BRANCH AREA PACING

Abstract

Leadless left ventricular (LV) endocardial pacing with the WiSE-CRT System (EBR Systems Inc) is an emerging treatment in the field of cardiac resynchronization therapy (CRT). Whilst the system was designed to provide LV lateral wall endocardial pacing, modifications to the implant technique have recently enabled positioning of the pacing electrode in the LV septum to perform left bundle branch area pacing (LBBAP). The electrical performance of leadless LBBAP is yet to be determined. We aimed to electro-anatomically characterize the biventricular (BiV) activation patterns of leadless LBBAP in patients with heart failure receiving CRT with the WiSE-CRT system. Four patients with the WiSE-CRT System, all with the pacing electrode located in the LV septum, underwent an electrocardiographic imaging (ECGi) study. The following pacing modalities were tested: Right Ventricular Pacing (RVP); BiV pacing (RVP + LV); LV only; and LV only with an electrically optimised atrioventricular delay (AVD) in patients with sinus rhythm. Reconstructed epicardial electrograms from ECGi were used to calculate LV activation time (LVAT-90), RV activation time (RVAT-90), BiV activation time (BIVAT-90), LV dyssynchrony index (LVDI), and BiV dyssynchrony index (BIVDI). For each metric, the percentage improvement compared to RVP was calculated. At the optimal pacing modality, CRT using leadless LV septal endocardial pacing achieved significant improvements in: LVAT-90 (33.9% ± 24.6, p=0.01); RVAT-90 (51.7% ± 24.1, p=0.003); BiVAT-90 (31.3% ± 30.8, p=0.03) and LV-DI (39.7% ± 39.7, p=0.03), see figure. There was individual variability in optimal pacing modality (see table). For 2 patients with sinus rhythm (SR) and left bundle branch block (LBBB), the optimal modality was LV only pacing with optimised AVD. Two patients had AF and complete heart block (CHB). For these cases, BiV pacing achieved the optimal results for 1 patient, whereas LV only pacing performed best for the other. Leadless LV LBBAP endocardial pacing significantly improves ECGi-derived activation metrics at the optimal pacing modality in both patients in SR and AF. For those with underlying SR and LBBB, LBBAP with AVD optimisation may be the optimal modality as this allows RV activation via native conduction. As each patient required a different protocol to achieve the optimal result, personalisation may be important for LV LBBAP.Tabled 1Optimized pacing setting by activation metric (PO-03-013)PatientUnderlying RhythmBiVAT-90LVAT-90RVAT-90LV-DIBiV-DI1AF, CHBLV onlyLV onlyLV onlyLV onlyLV only2SR, LBBBLV with optimized AVD 80msLV with optimized AVD 100msLV with optimized AVD 130msLV with optimized AVD 80msLV with optimized AVD 100ms3AF, CHBBiVLV onlyBiVLV onlyBiV4AF, LBBBLV only with optimized AVD 180msLV only with optimized AVD 160msLV only with optimized AVD 160msLV only with optimized AVD 160msLV only with optimized AVD 160ms Open table in a new tab