Pseudocolor plots of the local membrane potential illustrating plane-wave propagation through a transmural slice of our 2D simulation domain with a random distribution of myocytes and fibroblasts.

Here we consider the moderate-coupling case cm2/ms, and and in (a.1)–(a.5) the percentage of fibroblasts , in (b.1)–(b.5) , in (c.1)–(c.5) , in (d.1)–(d.5) , in (e.1)–(e.5) , and in (f.1)–(f.5) . As increases, not only does the distortion of the wavefront increase but the wave also propagates preferentially through the zone that has epicardial myocytes (rather than the zones with mid-myocardial and endocardial myocytes).(For full spatiotemporal evolutions see Video S3.).