Spatiotemporal chaos and spiral turbulence in models of cardiac Arrhythmias: an overview

Ventricular fibrillation (VF), the major reason behind sudden cardiac death, is turbulent cardian electrical activity in which rapid, irregular distrubances in the spatiotemoral electrical activation of the heart make it incapable of any concerted pumping action. Partial-differential-equation models of excitable media, based on reaction-diffusion equations, have proved to be very useful in the study of cardiac arrhythmias such as VF. We give an overview of such models, with special emphasis on the control and characterisation of the spiral turbulence and spatiotemporal chaos that occur in them. Such spiral turbulense is associated with VF, so its control has implications for difibrillation schemes.