ABSTRACT
190Measured myocardial conduction velocities vary markedly under different experimental conditions, specifically when measured along the longitudinal fiber axis or transverse to it, when measured under normal or ischemic conditions or when conduction is imposed during cellular recovery from excitability. We report here our attempt to study, by simulation, the effects of the different factors, which affect the conduction velocities, on the myocardial activation patterns. A finite-element, anisotropic, inhomogeneous model is used. The ischemic area is characterized by slow conduction. The embedded Purkinje network proximal to the ischemic area is blocked in the chronic case or intact in the acute case. Slowed conduction, associated with reactivation during the effective refractory period, is attributed to cells in neighboring areas to the infarction. The activation patterns reveal a nonmonotonic spread of activity in the ischemic area and a generation of reentry due to early reactivation.
