Propagating depolarization in anisotropic human and canine cardiac muscle: apparent directional differences in membrane capacitance. A simplified model for selective directional effects of modifying the sodium conductance on Vmax, tau foot, and the propagation safety factor.

Spach et al. (1987) studied Cardiac muscle electrophysiology. Quinidine and lidocaine was evaluated on Directionally dependent behavior of the upstroke (Vmax, conduction velocity, tau foot) in response to modification of sodium conductance. Quinidine and lidocaine produced greater relative decreases in Vmax and conduction velocity with longitudinal propagation than with transverse propagation in cardiac muscle.