Electroelastic unpinning of rotating vortices in biological excitable media

Spiral waves in excitable biological media are associated with pathological situations. In the heart anaction potential vortex pinned by an obstacle has to be removed through defibrillation protocols fine-tunedtheoretically by using electrophysiological nonlinear mathematical models. Cardiac tissue, however, is anelectroelastic medium whose electrical properties are strongly affected by large deformations. In this paperwe specifically investigate the electroelastic pinning-unpinning mechanism in order to include cardiaccontraction in the preexisting theoretically modeled defibrillation scenarios. Based on a two-dimensionalminimalelectromechanical model, we show numerically the existence of an unpinning band characterized by the sizeof the obstacle, the pacing site, and the frequency. Similar numerical simulations, performed in the absence ofelastic coupling, show small differences in comparison with the electroelastic studies, suggesting for this specificscenario of pinning-unpinning dynamics a nonprominent role of elasticity.