Drifting vortices of electrical waves underlie ventricular fibrillation in the rabbit heart.

Ventricular fibrillation is the most important cause of cardiac electrical instability leading to sudden death. Fibrillation is believed to be associated with complex three-dimensional (3-D) spatio-temporal patterns of electrical excitation of the myocardium. However, to this date, such patterns have not been directly observed or characterized, and little is known about their dynamics. In this paper, we present results that strongly support the hypothesis that at least some cases of ventricular fibrillation in the structurally normal heart may be the result of a single 3-D electrical scroll wave that moves rapidly throughout the ventricles, giving rise to complex patterns of cardiac muscle excitation.