Simulation study for anisotropic propagation of ventricular action potential with two-dimensional hexagonal model

Anisotropic propagation of cardiac action potential was studied using a two-dimensional hexagonal model which consists of single cells interconnected by gap junctional conduction (g_gap) with the six neighbouring cells. To examine the structural difference between the models for propagation properties, a one-dimensional model and a two-dimensional lattice model were also constructed. They have two and four gap connections, respectively. The size of the single cell was assumed to be 0.12 mm in length and 0.03 mm in diameter. Membrane properties of the cell were described by a modified DiFrancesco-Noble model with a revised sodium current description. Values of G _gap of each propagation model were adjusted to yield the conduction velocities measured experimentally. It was found that the hexagonal model could qualitatively explain experimental observations about anisotropic propagation. It is concluded that model structure definitely affects the shape of the propagating action potential