Dynamical effects of myocardial ischemia in anisotropic cardiac models in three dimensions

The interaction between the presence of moderate or severe subendocardial ischemic regions and the anisotropic structure of the cardiac muscle is investigated here by means of numerical simulations based on anisotropic Bidomain and Monodomain models. The ischemic effects on cardiac excitation, recovery and distribution of action potential duration are discussed, showing the presence of ischemic epicardial markers. Extracellular potential distributions during the ST and TQ intervals are computed separately using non-stationary models. During the ST interval, the extracellular potential patterns differ from those simulated with stationary models used in the literature. These differences are explained by decomposing the cardiac current sources into conormal, axial and orthogonal components and by determining which component is dominant during the ST and TQ intervals.