Phase Space Perturbations as a Defibrillation Technique in Cardiac Tissue

Contractions of the heart are based on the propagation of voltage waves of action potentials, which can destabilize and form spiral waves that can drive arrythmias. By observing action potentials in phase space, we can isolate the region of cells in the simulation which corelate to the same point in the action potential limit cycle. The tip of a spiral wave can be defined as an origin point within the action potential limit cycle in phase space. Previous studies show that a small stimulus across the refractory wave back allows for the instantaneous movement of the spiral wave's tip across physical space which allows for control and termination of spiral waves (defibrillation). We have expanded this study to include perturbations at any point during the action potential limit cycle which are capable of causing defibrillation. The defibrillation success relies on the size of the area perturbed and the strength of the perturbation across the phase singularity location in phase space. Here we demonstrate this defibrillation method in the FitzHugh-Nagumo model and other cardiac models.