Figure 9. Fate of an impulse arriving at high-curvature region.

A, time–space plots illustrating three different fates of an impulse propagating through a high curvature region: propagation (a), reflection (b) and block (c). Red dashed lines denote the expansion (increased curvature). B, fate of the wavefront as a function of peak I_Na and isthmus half-width at a low level of persistent I_Na (0.98%). C, fate of the wavefront as a function of peak I_Na and isthmus half-width at a higher level of persistent I_Na (1.27%). P, propagation through the region of high curvature; R, reflection at the region of high curvature; B, block at the region of high curvature.