A 2D monodomain model of rabbit sinoatrial node

A biophysically detailed two dimensional monodomain model of the rabbit sinoatrial node and surrounding atrial tissue has been developed. The model incorporates the heterogeneity of action potential characteristics, the anisotropy of tissue conductance properties and the complex geometry of the sinoatrial node. Previously published ionic models of single sinoatrial node and atrial cardiac myocytes have been employed to describe the underlying action potential characteristics. Tissue geometry and conductance properties were derived by interpolation over a coarse finite element mesh. The monodomain equation was solved using a collocation-derived finite difference method. It is anticipated that the model will yield novel insight into the mechanisms underlying action potential propagation from the sinoatrial node into the atrium, migration of the primary pacemaker site in response to vagal stimulation and other complex phenomena. Qualitative simulation results of action potential propagation are in accord with experimental observations.