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

Area of Science:

• Cardiovascular Electrophysiology
• Computational Cardiology
• Medical Device Technology

Background:

• The excitable gap (EG) is crucial for maintaining reentry in ventricular arrhythmias.
• EG within the His-Purkinje Network (HPN) significantly contributes to arrhythmogenesis.
• Understanding EG dynamics is key to developing anti-arrhythmic strategies.

Purpose of the Study:

• To investigate if rapid His bundle pacing (HBP) can reduce EG in the HPN and ventricular myocardium.
• To assess HBP's potential to suppress reentry maintenance.
• To determine if HBP improves defibrillation efficacy during ventricular arrhythmias.

Main Methods:

• A virtual human biventricular model was used to simulate reentry.
• Reentry was initiated, followed by HBP at various pacing cycle lengths (PCLs).
• EG was quantified in the HPN and myocardium; defibrillation efficacy was tested with and without HBP under normal and bundle branch block conditions.

Main Results:

• HBP significantly reduced EG in the HPN and myocardium across a range of PCLs in all tested models.
• HBP exceeding 6 seconds terminated reentrant arrhythmias by restoring sinus rhythm in normal and RBBB models.
• Myocardial EG stimulation during HBP increased defibrillation success rates by 3%-19%.

Conclusions:

• HBP effectively reduces the excitable gap, suppressing reentry maintenance in the HPN and myocardium.
• HBP enhances the efficacy of low-energy defibrillation targeting the excitable myocardium.
• HBP presents a promising anti-arrhythmic and defibrillation strategy for reentrant arrhythmias.