Figure 3.

Electrotonic effects of the center of rotation (core) on conduction velocity (CV) action potential duration (APD) and wavelength (WL). During reentry the wavefront adopts a spiral shape with increasing curvature toward the core. A. During sustained reentry, the CV of the wave front slows gradually toward the center (solid arrows), reaching a critical value at the immediate perimeter of the core. As a result, the core remains unexcited. Consequently, a voltage gradient develops between the unexcited core and the neighboring active cells. B. Electrotonic currents between the core and its immediate neighbors shorten APD near the core (broken trace and horizontal arrow). Hence, wavelength (WL= CV × APD) near the core is much shorter than WL far away from the core.