| Mathematical models for simulating the electrical propagation phenomena in the heart can provide a noninvasive way to study normal activity in the heart, as well as cardiac diseases such as ischaemia, tachycardia, arrhythmia, and infarction. The microscopic and macroscopic level modeling of cardiac activation in the Dalhousie propagation (hybrid) model is described in detail. At the microscopic level, the subthreshold behaviour of each cell is governed by a reaction-diffusion equation derived from anisotropic bidomain theory; the suprathreshold behaviour is governed by a set of cellular automata rules. Each cell is assigned a principle fiber direction according to their placement in a realistic 3D heart geometry, consisting of the left and right ventricles obtained from frozen 1.0 mm slices of heart tissue. At the macroscopic level, the propagation of excitation is controlled be an anatomically accurate conduction system: the wave propagates through the conduction system to the Purkinje-myocardial junction sites, where it enters the ventricular myocardium. (Abstract shortened by UMI.). |
