In computational models of severe LV His-Purkinje disease, CRT improved electrical synchrony over His bundle pacing (93.0 vs 101.5 ms, p<0.05), with further gains from HOT-CRT and LOT-CRT.
Does conduction system pacing improve electrical synchrony compared to conventional CRT in computational models with varying conduction disease and scar?
Computational modeling suggests that severe LV His-Purkinje disease and septal scars attenuate the benefits of conduction system pacing, favoring conventional or optimized CRT, whereas slow myocardial conduction favors conduction system pacing.
INTRODUCTION: Conduction system pacing (CSP), in the form of His bundle pacing (HBP) or left bundle branch pacing (LBBP), is emerging as a valuable cardiac resynchronization therapy (CRT) delivery method. However, patient selection and therapy personalization for CSP delivery remain poorly characterized. We aim to compare pacing-induced electrical synchrony during CRT, HBP, LBBP, HBP with left ventricular (LV) epicardial lead (His-optimized CRT HOT-CRT), and LBBP with LV epicardial lead (LBBP-optimized CRT LOT-CRT) in patients with different conduction disease presentations using computational modeling. METHODS: We simulated ventricular activation on 24 four-chamber heart geometries, including His-Purkinje systems with proximal left bundle branch block (LBBB). We simulated septal scar, LV lateral wall scar, and mild and severe myocardium and LV His-Purkinje system conduction disease by decreasing the conduction velocity (CV) down to 70% and 35% of the healthy CV. Electrical synchrony was measured by the shortest interval to activate 90% of the ventricles (90% of biventricular activation time BIVAT-90). RESULTS: Severe LV His-Purkinje conduction disease favored CRT (BIVAT-90: HBP 101.5 ± 7.8 ms vs. CRT 93.0 ± 8.9 ms, p < .05), with additional electrical synchrony induced by HOT-CRT (87.6 ± 6.7 ms, p < .05) and LOT-CRT (73.9 ± 7.6 ms, p < .05). Patients with slow myocardium CV benefit more from CSP compared to CRT (BIVAT-90: CRT 134.5 ± 24.1 ms; HBP 97.1 ± 9.9 ms, p < .01; LBBP: 101.5 ± 10.7 ms, p < .01). Septal but not lateral wall scar made CSP ineffective, while CRT was able to resynchronize the ventricles in the presence of septal scar (BIVAT-90: baseline 119.1 ± 10.8 ms vs. CRT 85.1 ± 14.9 ms, p < .01). CONCLUSION: Severe LV His-Purkinje conduction disease attenuates the benefits of CSP, with additional improvements achieved with HOT-CRT and LOT-CRT. Septal but not lateral wall scars make CSP ineffective.
Strocchi et al. (Sat,) conducted a other in Conduction disease (n=24). Conduction system pacing vs. Cardiac resynchronization therapy (CRT) was evaluated on Shortest interval to activate 90% of the ventricles (BIVAT-90). In computational models of severe LV His-Purkinje disease, CRT improved electrical synchrony over His bundle pacing (93.0 vs 101.5 ms, p<0.05), with further gains from HOT-CRT and LOT-CRT.