Ionic-heterogeneity-induced spiral- and scroll-wave turbulence in mathematical models of cardiac tissue

Spatial variations in the electrical properties of cardiac tissue can occur because of cardiac diseases. We introduce such gradients into mathematical models for cardiac tissue and then study, by extensive numerical simulations, their effects on reentrant electrical waves and their stability in both two and three dimensions. We explain the mechanism of spiral- and scroll-wave instability, which entails anisotropic thinning in the wavelength of the waves because of anisotropic variation in its electrical properties.