Dose reponse behavior in a physiologically accurate defibrillation model

Termination of an episode of ventricular fibrillation by electric countershock is a probabilistic phenomenon. In a clinical or experimental setting, defibrillation exhibits dose-response behavior. We demonstrate for the first time that a physiologically and anatomically accurate model of defibrillation is able to simulate this dose-response behavior. We also demonstrate the ability of this computational model to reproduce the full range of observed shock responses. Finally, we show that the brief cessation of electrical activity on the epicardial surface after a shock near the defibrillation threshold, the isoelectric window, can be explained by the slowed propagation velocity of transmural activation wavefronts around a filament of singularity in the myocardium