Effect of scar and His–Purkinje and myocardium conduction on response to conduction system pacing. (14th February 2023)

• Record Type: Journal Article
• Authors: Strocchi, Marina; Gillette, Karli; Neic, Aurel; Elliott, Mark K.; Wijesuriya, Nadeev; Mehta, Vishal; Vigmond, Edward J.; Plank, Gernot; Rinaldi, Christopher A.; Niederer, Steven A.
• Is Part Of: Journal of cardiovascular electrophysiology. Volume 34:Number 4(2023)
• Page Start: 984
• Page End: 993
• Publication Date: 2023-02-14
• Subjects: cardiac resynchronization therapy -- conduction system pacing -- heart failure -- His bundle pacing -- left bundle branch block -- left bundle pacing; Blood vessels -- Physiology -- Periodicals; Electrophysiology -- Periodicals; Heart -- Physiology -- Periodicals; 612.1
• DOI: 10.1111/jce.15847
• Languages: English
• ISSNs: 1045-3873

Abstract

Abstract: 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. Abstract : The yellow area represents the His bundle, with a proximal block (red cross) introduced along the strands going to the left bundle. The left ventricular and the right ventricular Purkinje system are represented in orange and blue, and the ventricular myocardium is depicted in gray. Black areas in the two bottom images represent scars. Abbreviations as in Figure 1. Other abbreviations: CRT, cardiac resynchronization therapy; CSP, conduction system pacing; HOT‐CRT, His‐optimized CRT; LOT‐CRT, LBBP‐optimized CRT.