Computational Modelling of Selective Capture Mechanisms in Conduction System Pacing

Area of Science:

• Cardiovascular Electrophysiology
• Biomedical Engineering
• Computational Modeling

Background:

• Conduction system pacing (CSP) aims to restore physiological ventricular activation.
• His bundle pacing is ideal but technically challenging.
• Left bundle branch area pacing (LBBP) offers a simpler alternative for physiological activation.

Purpose of the Study:

• To quantitatively elucidate mechanisms of selective LBBP.
• To investigate the impact of lead parameters on selective LBBP.
• To understand factors influencing optimal LBBP thresholds.

Main Methods:

• Developed a detailed computer model of the interventricular septum and left bundle branch (LBB).
• Utilized a clinically relevant CSP lead model.
• Simulated lead position, orientation, and polarity effects on LBBP.

Main Results:

• Deep subendocardial implantation with direct electrode-LBB contact is crucial for selective LBBP.
• Higher stimulation strengths may lead to non-selective capture.
• Lead orientation significantly affects capture thresholds and bundle activation synchrony.

Conclusions:

• The model explains observed clinical impedance trends and complications.
• Simulation findings support the potential for improved CSP lead design.
• Accurate modeling can guide strategies for selective and synchronous LBB activation.