Initiation and dynamics of a spiral wave around an ionic heterogeneity in a model for human cardiac tissue

摘要

In relation to cardiac arrhythmias, heterogeneity of cardiac tissue is one of the most important factors underlyingnthe onset of spiral waves and determining their type. In this paper, we numerically model heterogeneity of realisticnsize and value and study formation and dynamics of spiral waves around such heterogeneity.We find that the onlynsustained pattern obtained is a single spiral wave anchored around the heterogeneity. Dynamics of an anchorednspiral wave depend on the extent of heterogeneity, and for certain heterogeneity size, we find abrupt regionalnincrease in the period of excitation occurring as a bifurcation.We study factors determining spatial distribution ofnexcitation periods of anchored spiral waves and discuss consequences of such dynamics for cardiac arrhythmiasnand possibilities for experimental testings of our predictions.