Fig. 3.

Spiral wave initiation due to a FPR in a 2D inhomogeneous medium. Within the left-hand part of the central circular FPR $D=D_0=\hspace{0.17em}2$ (dense filling). Within the right-hand part, $D/D_0=\hspace{0.17em}2/3$ (rare filling). Within the rest of the medium, $D/D_0=\hspace{0.17em}1/2$. Snapshots of a left-traveling wave (A–C) and a wave propagating in the opposite direction (D–F) are shown. The trajectories of the created phase-change points are shown by white lines (E and F).