QUENCHING A ROTATING VORTEX IN AN EXCITABLE MEDIUM

We describe two mechanisms for the destruction of a rotating wave in a n excitable medium by using (1) a wave containing no topological defec ts, and (2) a wave with a pair of topological defects of opposite char ge. Both mechanisms result in the displacement of the core of the defe ct, and can be repeated as needed to expel the rotating wave out of th e system. These two mechanisms provide a way of controling initial sta ges of spatiotemporal chaos in excitable media. Applications to cardia c fibrillation are discussed.