Effect of straining on spiral wave dynamics in excitable media

The present article envisages to explore the dynamics of stable rotating spiral waves in excitable media under the effect of shear strain through the Oregonator model. We employ an existing unconditionally stable, implicit high order compact finite difference scheme to discretize the highly nonlinear system governing the spiral wave patterns. In the process, we also study the effect of reaction parameters on the dynamics of spiral waves in the absence of straining, which results in the transition from the stable (periodic) rotation to compound (non-periodic) rotation of spiral waves. Our study reveals the existence of three regimes with a new time range, which is different from the earlier ones reported in literature; they characterize the extremely complex behaviour of the patterns under the effect of straining. The aforesaid conclusion is arrived at by carrying out a comprehensive analysis of the power spectrum of the tip motion. Besides establishing the stability of simulated rotating waves, the accuracy of the computed solutions has been ascertained through a convergence analysis and mesh independence study. (C) 2020 Elsevier B.V. All rights reserved.