Simple finite-element model accounts for wide range of cardiac dysrhythmias.

Abstract

A simple finite-element model of ventricular conduction processes that explicitly incorporates spatial dispersion of refractoriness was developed. This model revealed that spatial dispersion of refractoriness is a sufficient condition to produce self-sustained reentry even in the absence of unidirectional block, inhomogeneity in local conduction velocities, or the presence of ectopic pacemakers. The model displayed a wide variety of rhythm disturbances qualitatively similar to clinically familiar cardiac dysrhythmias. Electrical stability of the model was determined as a function of the model parameters including ventricular stimlation rate, conduction velocity, and mean refractory period as well as standard deviation of refractory periods. Evidently, spatial dispersion of refractoriness is a sufficient condition to initiate reentrant dysrhythmias but other physiologic variables such as ventricular rate and conduction velocity strongly influence the dysrhythmogenic effect of spatial dispersion of refractoriness.