Wave Propagation in Excitable Media with Randomly Distributed Obstacles

We study the effect of small, randomly distributed obstacles on wave propagation in two-dimensional (2D) and 3D excitable media described by the Aliev–Panfilov model. We find that increasing the number of obstacles decreases the conduction velocity of plane waves and decreases the effective diffusion coefficient in the eikonal curvature equation. The presence of obstacles also increases the inducibility of wave breaks and spiral waves in 2D and 3D excitable media, but suppresses spiral breakup induced by a steep restitution curve mechanism. We discuss the mechanisms of the observed effects, the differences between 2D and 3D excitable media, as well as the relevance of our study to processes of wave propagation in cardiac tissue, including arrhythmogenesis in the presence of fibrosis in the myocardium.