In a 3D canine heart model, increasing defibrillation shock strength decreased the number of surviving phase singularities over 200 ms, though behavior strongly depended on electrode configuration.
In a computational canine heart model, failed defibrillation shocks are characterized by surviving phase singularities that establish new arrhythmias, with survival dependent on shock strength and electrode configuration.
The focus of this article is the investigation of the electrical behavior of the normal myocardium following the delivery of high-strength defibrillation shocks. To achieve its goal, the study employs a complex three-dimensional defibrillation model of a slice of the canine heart characterized with realistic geometry and fiber architecture. Defibrillation shocks of various strengths and electrode configurations are delivered to the model preparation in which a sustained ventricular tachycardia is induced. Instead of analyzing the post-shock electrical events as progressions of transmembrane potential maps, the study examines the evolution of the postshock phase singularities (PSs) which represent the organizing centers of reentry. The simulation results demonstrate that the shock induces numerous PSs the majority of which vanish before the reentrant wavefronts associated with them complete half of a single rotation. Failed shocks are characterized with one or more PSs that survive the initial period of PS annihilation to establish a new postshock arrhythmia. The increase in shock strength results in an overall decrease of the number of PSs that survive over 200 ms after the end of the shock; however, the exact behavior of the PSs is strongly dependent on the shock electrode configuration. (c) 2002 American Institute of Physics.
Trayanova et al. (Fri,) conducted a other in Ventricular tachycardia. High-strength defibrillation shocks was evaluated on Evolution of postshock phase singularities (PSs). In a 3D canine heart model, increasing defibrillation shock strength decreased the number of surviving phase singularities over 200 ms, though behavior strongly depended on electrode configuration.