New Mechanisms of Disorder Tissue Model

We study dynamical regimes in a two dimensional excitable medium driven by a cluster of nonidentical oscillatory elements inside of it. In general, similar topologies take place e.g. in heart, where Sino-Atrial Node (SAN) is surrounded by excitable cells of atrial tissue. Moreover, the topology of SAN of rabbit is effectively two dimensional due to very small thickness of tissue in that region. That makes this study even more plausible. Our numerical experiments with FitzHugh-Nagumo and Luo-Rudy I models show that instant pathological change in oscillatory cells can trigger drastical changes to the dynamical regimes of the whole lattice. Several mechanisms of that kind are presented and discussed in this paper. For instance, we show that increasing oscillatory elements' nonidentity can cause wave propagation defects resulting in the onset of the spiral waves in the excitable media.