Spatiotemporal dynamics of ventricular tachycardia and ventricular fibrillation

Ventricular tachycardia and ventricular fibrillation are potentially lethal heart rhythms that can cause sudden cardiac death. The electrical events in the heart that are associated with these complex rhythms are not well understood. We will employ computer simulations of cardiac electrical activity to study these rhythms, and examine how they can be best detected in body-surface electrocardiograms. A mathematical model of cardiac cell membrane will simulate accurately the electrical behaviour of different kinds of myocardial cells, enabling physiologically accurate study of electrical propagation phenomena and of stability of electrical waves in a computer replica of the human heart's complex anatomical structure (which has anisotropic electrical properties and includes a network of fast-conducting fibres on its inner surface). In our previous studies, we reproduced two-dimensional spiral waves and three-dimensional scroll waves of electrical activation that are observed during animal experiments. Stability of these waves was altered by varying electrical properties of cardiac cells, and we were able to simulate the onset of ventricular fibrillation. By simulating the effects of antiarrhythmic drugs and of defibrillation shocks, as proposed in this application, we will gain a valuable insight into treatment of malignant heart rhythms.