Potential distribution in three-dimensional periodic myocardium. II. Application to extracellular stimulation

For pt.I see ibid., vol.37, no.3, p.252-66 (1990). Modeling potential distribution in the myocardium treated as a periodic structure implies that activation from high-current stimulation with extracellular electrodes is caused by the spatially oscillating components of the transmembrane potential. This hypothesis is tested by comparing the results of the model with experimental data. The conductivity, fiber orientation, extent of the region, location of the pacing site, and stimulus strength determined from experiments are components of the model used to predict the distributions of potential, potential gradient, and transmembrane potential throughout the region. Assuming that a specific value of the transmembrane potential is necessary and sufficient to activate fully repolarized myocardium, the model provides an analytical relation between large-scale field parameters, such as gradient and current density, and small-scale parameters, such as transmembrane potential.