Vortices with linear cores in excitable media

Abstract
Most naturally occurring excitable media exhibit vortex waves with circular cores. It has been reported that the spiral wave activity in cardiac muscle may revolve around longitudinal or elliptical cores. Here we demonstrate that spiral wave vortices with cores resembling a long line may result from decreasing a small parameter which affects the recovery time in an isotropic and homogeneous excitable reaction-diffusion model. The model results compare well with experimental data in cardiac muscle.