The role of mechano-electric feedbacks and hemodynamic coupling in scar-related ventricular tachycardia

TL;DR

This study investigates how mechano-electric feedbacks and hemodynamic coupling influence scar-related ventricular tachycardia using detailed 3D electromechanical models, revealing their effects on VT propagation and stability.

Contribution

It introduces a comprehensive electromechanical-hemodynamic modeling framework to analyze the impact of MEFs and SACs on VT in a realistic 3D setting.

Findings

MEFs can alter action potential propagation and VT morphology.

Myocardial deformation affects VT cycle length and conduction velocity.

SACs can switch VT stability between stable and unstable states.

Abstract

Mechano-electric feedbacks (MEFs), which model how mechanical stimuli are transduced into electrical signals, have received sparse investigation by considering electromechanical simulations in simplified scenarios. In this paper, we study the effects of different MEFs modeling choices for myocardial deformation and nonselective stretch-activated channels (SACs) in the monodomain equation. We perform numerical simulations during ventricular tachycardia (VT) by employing a biophysically detailed and anatomically accurate 3D electromechanical model for the left ventricle (LV) coupled with a 0D closed-loop model of the cardiocirculatory system. We model the electromechanical substrate responsible for scar-related VT with a distribution of infarct and peri-infarct zones. Our mathematical framework takes into account the hemodynamic effects of VT due to myocardial impairment and allows for the classification of their hemodynamic nature, which can be either stable or unstable. By combining electrophysiological, mechanical and hemodynamic models, we observe that all MEFs may alter the propagation of the action potential and the morphology of the VT. In particular, we notice that the presence of myocardial deformation in the monodomain equation may change the VT basis cycle length and the conduction velocity but do not affect the hemodynamic nature of the VT. Finally, nonselective SACs may affect wavefront stability, by possibly turning a hemodynamically stable VT into a hemodynamically unstable one and vice versa.