Simulation of cardiac conduction system in distributed computer environment.

A high resolution, three dimensional, computer model of the cardiac conduction system has been developed. Cardiac geometry was constructed from sectional images of VHP project of the National Library of Medicine. The heart was modeled as a matrix of cells that fill its anatomical structure. The intracellular distance was 1 mm and the total number of cells were 457,482. Electrophysiological parameters like action potential, absolute refractory period and conduction velocity were assigned to each of the cells. The pattern of the excitation sequence propagation as well as potentials on the body surface points were computed on a single processor. The working memory and the time for computation of the algorithms were minimized using efficient data structures. The time to compute an excitation sequence over one cardiac cycle was 4 hours. The algorithms were also implemented on a distributed network of personal computers running on a QNX operating system. The speed of computation of the excitation sequence algorithm was improved by a factor of 2.52 when the algorithm was implemented on a network of three Intel-66 MHz machines.