Propagation wavefronts in two-dimensional topologies of cardiac cell networks

The authors present a computer model, implemented on a Cray-2 supercomputer, to explore the role of the discontinuous, nonuniform and anisotropic cellular structure of cardiac tissue on normal propagation patterns. For this study, they held the cell shape constant and evaluated planar propagation wavefronts oriented longitudinally and transversely to the cell axis for two different tissue topologies, rectangular and brick-like, and for different degrees of transverse coupling strengths between cells. Nonuniformity was introduced into the model via spatial dispersions of coupling strengths. Even under severe conditions of uncoupling, both topologies showed remarkable abilities in maintaining a uniformly planar wavefront. Thus, the simulations suggest that cardiac cell networks are very robust in their abilities to equilibrate electrical spatial inhomogeneities, even in the face of significant structural and coupling inhomogeneities