Boundary layer heterogeneities can enhance scroll wave stability

The electrical activity in the heart is affected by the presence of scroll waves, causing lifethreatening arrhythmias. Clinical procedures to handle these electrical disorganizations create nonconductive heterogeneities in the cardiac tissue. We explore how boundary layer heterogeneities affect the scroll wave dynamics in a semidiscrete electrophysiological model. We show that decreasing the coupling strength near the boundaries of the tissue can prevent a meandering instability in the bulk enhancing the stability of scroll waves confined to thin geometries. Based on the coupling strength, the boundary layer length, the slab thickness, and wave deformation, we propose a forced model to reveal how a heterogeneity-induced slowing down of the waves governs the stabilization.