Spiral Waves in a Simplified Model of Cardiac Tissue

Abstract

Spiral waves in models of cardiac tissue are analog of fibrillation in mammalian heart, which may arise from the ionic levels during various disease conditions. In this study, we show how spiral wave states are affected when conductances of ionic currents of a simplified cardiac tissue model are changed from their normal values. Our systematic study shows that there are four different spiral states possible when we vary Gca and (or) Gk ionic conductances; these states are (a) a periodic spiral (PS) state, (b) a quasi spiral (QS) state, (c) a state of absorbed spiral (AS), and (d) a state of no spiral (NS) activity. The stability diagrams on Gca − Gk parameter space reveal the sensitive dependence of these spiral states on initial spiral configurations, which is a characteristic feature of many dynamical systems.