A His bundle pacing protocol for suppressing ventricular arrhythmia maintenance and improving defibrillation efficacy

• Published in: Computer methods and programs in biomedicine Vol. 253; p. 108239
• Main Authors: Bayer, Jason D., Sobota, Vladimír, Bear, Laura R., Haïssaguerre, Michel, Vigmond, Edward J.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.08.2024
• Subjects: Arrhythmias, Cardiac - therapy; Bundle of His - physiopathology; Cardiac Pacing, Artificial - methods; Computer modeling and simulation; Defibrillation; Electric Countershock - methods; Excitable gap; Heart Ventricles - physiopathology; His Bundle pacing; Humans; Models, Cardiovascular; Purkinje network; Reentry; Ventricular arrhythmia; EG; Excitable gap; Reentry; Computer modeling and simulation; HPN; Ventricular arrhythmia; ICD; VF; His Bundle pacing; APD; HBP; PCL; Purkinje network; Defibrillation; HVM; VT
• ISSN: 0169-2607; 1872-7565; 1872-7565
• DOI: 10.1016/j.cmpb.2024.108239

The excitable gap (EG), defined as the excitable tissue between two subsequent wavefronts of depolarization, is critical for maintaining reentry that underlies deadly ventricular arrhythmias. EG in the His-Purkinje Network (HPN) plays an important role in the maintenance of electrical wave reentry that underlies these arrhythmias. To determine if rapid His bundle pacing (HBP) during reentry reduces the amount of EG in the HPN and ventricular myocardium to suppress reentry maintenance and/or improve defibrillation efficacy. In a virtual human biventricular model, reentry was initiated with rapid line pacing followed by HBP delivered for 3, 6, or 9 s at pacing cycle lengths (PCLs) ranging from 10 to 300 ms (n=30). EG was calculated independently for the HPN and myocardium over each PCL. Defibrillation efficacy was assessed for each PCL by stimulating myocardial surface EG with delays ranging from 0.25 to 9 s (increments of 0.25 s, n=36) after the start of HBP. Defibrillation was successful if reentry terminated within 1 s after EG stimulation. This defibrillation protocol was repeated without HBP. To test the approach under different pathological conditions, all protocols were repeated in the model with right (RBBB) or left (LBBB) bundle branch block. Compared to without pacing, HBP for >3 seconds reduced average EG in the HPN and myocardium across a broad range of PCLs for the default, RBBB, and LBBB models. HBP >6 seconds terminated reentrant arrhythmia by converting HPN activation to a sinus rhythm behavior in the default (6/30 PCLs) and RBBB (7/30 PCLs) models. Myocardial EG stimulation during HBP increased the number of successful defibrillation attempts by 3%–19% for 30/30 PCLs in the default model, 3%–6% for 14/30 PCLs in the RBBB model, and 3%–11% for 27/30 PCLs in the LBBB model. HBP can reduce the amount of excitable gap and suppress reentry maintenance in the HPN and myocardium. HBP can also improve the efficacy of low-energy defibrillation approaches targeting excitable myocardium. HBP during reentrant arrhythmias is a promising anti-arrhythmic and defibrillation strategy. [Display omitted] •A state-of-the-art computational approach was used to investigate how rapid His bundle pacing alters the maintenance and defibrillation efficacy of reentrant ventricular arrhythmias.•This study identified that His bundle pacing at specific frequencies reduces the amount of excitable gap in the His-Purkinje Network and myocardium simultaneously. This in turn suppresses reentry maintenance and improves the efficacy of low-energy defibrillation strategies targeting myocardial excitable gap.•The promising results of this study open the door for the His bundle pacing protocol to be used in implantable medical devices for improving the efficacy of low-energy defibrillation strategies for patients vulnerable to lethal ventricular arrhythmias.