Non-invasive assessment of ventricular electrical heterogeneity to optimize left bundle branch area pacing

Left bundle branch area pacing (LBBAP) is a novel therapeutic option for bradycardia and heart failure patients. ECG belt is a novel technology for assessment of ventricular electrical heterogeneity (VEH) using multi-electrode ECG. A metric of overall VEH based on standard deviation of activation times (SDAT) from all electrodes in the ECG belt has been previously shown to predict cardiac resynchronization therapy (CRT) response. The aim of the study is to evaluate non-invasive assessment of VEH using ECG belt to optimize LBBAP.

VEH from a 40-electrode ECG belt was characterized in 20 patients (male 15, EF 33 ± 13%, NYHA class 3.05 ± 0.6; CRT indication 18) during LBBAP (20) and LBBAP-Optimized CRT (LOT-CRT-7), anodal capture (16), NS-LBBP (18), S-LBBP (5), LVSP (9). In addition to SDAT, regional (LV/RV) VEH was assessed with average left ventricular activation times (LVAT), SDAT of left-sided (LV dispersion) and right-sided (RV dispersion) electrodes. Optimal LBBAP was determined based on maximal SDAT and QRS duration (d) change.

All metrics were significantly reduced (p < 0.0001 for ECG belt metrics, p = 0.0027 for QRSd) during LBBAP and LOT-CRT compared to intrinsic. QRSd, SDAT, LVAT, and LV and RV dispersion during optimal LBBAP were significantly lower (133 ± 20/157 ± 24; 20.5 ± 7.5/38.6 ± 9; 44.4 ± 14.3/61.4 ± 21; 11.6 ± 11.6/29.5 ± 15; 21.1 ± 7.8/42.5 ± 9.3; p < 0.0001) compared to intrinsic rhythm. However, they were not significantly different among selective, non-selective, anodal, and LV septal captures. EF and NYHA class improved to 46 ± 11% and 1.9 ± 0.6 (p < 0.001).

LBBAP significantly reduced overall and regional (RV/LV) VEH, irrespective of the mechanism of capture. Detailed assessment of electrical heterogeneity using ECG belt may add valuable insights on effects of LBBAP.

ClinicalTrials.gov Identifier: NCT04583709.