Comparing the acute biventricular hemodynamic effects of left bundle branch area pacing (LBBAP) and left bundle optimized cardiac resynchronization therapy (LOT-CRT)

Background Left bundle branch area pacing (LBBAP) and left bundle optimized cardiac resynchronization therapy (LOT-CRT) are emerging forms of cardiac resynchronization therapy. We sought to evaluate the impact of LBBAP and LOT-CRT on left and right ventricular hemodynamics. Methods Eight patients with LBBAP underwent invasive biventricular hemodynamic testing and temporary pacing using intracardiac catheters. The maximum rate of left (LV dp/dtmax) and right ventricular pressure rise (RV dp/dtmax) were measured at baseline, during LBBAP and during temporary LOT-CRT. Results There was no significant difference in the mean ∆ LV dp/dtmax between LBBAP and LOT-CRT (72.1 ± 128.6 mmHg/s vs. 72.3 ± 100.4 mmHg/s respectively; P = 0.99) compared to baseline. Similarly, ∆ RV dp/dtmax (mmHg/s) did not differ significantly (LBBAP -21.1 ± 64.3 mmHg/s vs. LOT-CRT -38.3 ± 74.7 mmHg/s; P = 0.64). The mean QRS duration reduction was 25.4 ± 28.3 ms vs 17.7 ± 23.5 ms for LBBAP and LOT-CRT respectively (P = 0.58). Conclusion Both LBBAP and LOT-CRT resulted in improved LV contractility at the expense of reduced RV contractility. The biventricular hemodynamic effects were comparable between LBBAP and LOT-CRT.