Spatiotemporal chaos due to spiral waves core expansion and its elimination in excitable media

In the framework of the Fitzhugh-Nagumo kinetics and the oscillatory recovery in excitable media, we present a new type of meandering of the spiral waves, which leads to spiral break up and spatiotemporal chaos. The tip of the spiral follows an outward spiral-like trajectory and the spiral core expands in time. This type of destabilization of simple rotation is attributed to the effects of curvature and the wave-fronts interactions in the case of oscillatory damped recovery to the rest state. This model offers a new route to and caricature for cardiac fibrillation, and when we apply the feedback resonant drift method, for defibrillation all wave activity gets eliminated at the unexcitable boundaries.