Success and failure of the defibrillation shock: does it depend onthe fiber field?

摘要

This modeling study demonstrates that shocks of the same strengthand duration are more successful in extinguishing spiral wave activityin cases when the preparation incorporates fiber curvature. The tissueis represented as a two-dimensional bidomain of unequal anisotropyratios. Stable reentry is induced via cross-field stimulation of themyocardial sheet. The defibrillation shock is delivered by extracellularline electrodes located at opposite tissue borders. The simulationresults demonstrate that the defibrillation shock induces virtualelectrodes in the curved fiber preparation. These virtual electrodes areresponsible for depolarizing the tissue away from the physical cathodeand for giving rise to new activation fronts after the defibrillationshock. Thus, shocks of the same strength and duration are successful inpreparations with fiber curvature, while in straight-fiber preparationsthey only minimally disturb the spiral wave