Isotropic and homogeneous approximation of myocardial tissue resistivity behavior

The goal of this work is to develop a mathematical model that was accurately predict the best fit parameters and errors to be encountered in the simplification of the anisotropic and inhomogeneous electrical characteristics of the cardiac muscle to an isotropic and homogeneous tissue equivalent. A numerical model based on the finite difference method developed and validated for description of skeletal muscle (anisotropic) resistivity behavior. It was expanded and used to simulate the resistivity behavior of myocardial samples at different levels of anisotropy and inhomogeneity. The results obtained from this investigation indicate that for realistic geometries of cardiac muscle, isotropization and homogenization simplification error is less than 0.5 /spl Omega/-m. This prediction is based on the simulated results obtained with the incorporation of relevant physiological and morphological information on the tissue into the numerical model.