Field stimulation of a three-dimensional bidomain block incorporating rotational anisotropy

A bidomain model of cardiac tissue was used to examine the effect of anisotropy on field stimulation in two- and three-dimensional myocardium. A two-dimensional tissue sheet (with equal and unequal anisotropy ratios), and a three-dimensional tissue block (with unequal, rotational anisotropy) were placed in a uniform electric field, and the resulting interstitial and transmembrane potentials were computed. Results show that both the interstitial and transmembrane potentials are sensitive to the anisotropy ratios, and that the rotational anisotropy in three-dimensional tissue averages out the effect of the electric field in a manner that may depend on the magnitude of the transmural current redistribution.