Boundary layer heterogeneities in cardiac tissue can enhance scroll wave stability

Spatiotemporal dynamics, such as turbulence in active matter, oscillations in chemical reactions, and disorganization of electrical waves in cardiac tissue, pose significant challenges in many physical and biological systems. A key question in these contexts is how to control such complex dynamics, which is particularly relevant in the framework of cardiac dynamics where scroll wave dynamics may cause life-threatening arrhythmias. We explore how boundary layer heterogeneities affect the scroll wave dynamics in a semidiscrete electrophysiological model. Using numerical simulations, we demonstrate that the introduction of the boundary layer heterogeneity can prevent a meandering instability of scroll waves. We address the suppression of the meandering bifurcation by weakly nonlinear analysis. Finally, we derive a simplified model that only considers activation in the boundary layer and in one bulk tissue slice, and show that this model is able to capture the numerically observed stabilization of scroll waves. We discuss the extension of our results in terms of controlling more complicated spatiotemporal dynamics such as scroll wave break-up. Our findings suggest a novel approach to controlling arrhythmias with minimal tissue intervention, which can be essential for treating patients with tachycardia and fibrillation.