title: Spiral waves in excitable media with negative restitution.
abstract: We study numerically the dynamics of spiral waves in an excitable medium with negative restitution. For our study we use two models of the excitable medium: a cellular automaton and a reaction-diffusion model. There are no significant effects of negative restitution as long as the slope of the restitution curve is less steep than -1. In media with slopes steeper than -1, the dynamics of spiral waves can change significantly: (1) the average restitution time jumps to a value where the slope of the restitution curve is about -1; (2) spiral waves can break up into turbulent patterns. We discuss a possible connection between such instabilities and fibrillation in atrial tissue.
authors: Innovationskolleg Theoretische Biologie, Invalidenstrasse 43, 10115 Berlin, Germany.
authors: C W
authors: CW
authors: Zemlin
authors: A V
authors: AV
authors: Panfilov
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac; D055592:Biophysical Phenomena; D001703:Biophysics; D003198:Computer Simulation; D004594:Electrophysiology; D006321:Heart; D006329:Heart Conduction System; D008955:Models, Cardiovascular; D017180:Tachycardia, Ventricular; D014693:Ventricular Fibrillation