Figure 6.

Simulation of homogeneous, anisotropic electrical activity (i.e. assuming a single cell type and fibre structure only, no sheets) in a rat geometry obtained using DT-MRI, with (0.2 mm³) voxels. (a) Fibre helix angle. (b) Computed activation times for an epicardial stimulation analogous to that in figure 5. (c) Corresponding APDs. (d) Action potentials recorded from voxels with early (top) and late (bottom) activation times. Note the modulation of the action potential morphology by the activation sequence in the electrically homogeneous domain—later activation times result in decreased APDs.