Effect of the Human Heart Material Anisotropy on Modeling of the Body Surface Potential Map

This study investigates the effect of assuming isotropic properties for the heart's myocardium on the Body Surface Potential Map (BSPM) under both homogeneous and inhomogeneous torso volume conductor models. The human torso was modeled as an inhomogeneous volume using CT data, and the heart as a volume source based on diffusion tensor imaging (DTI), incorporating both anisotropic and isotropic conductivity assumptions. Using the Monodomain Reaction-Diffusion Equation (MD-RDE), excitation propagation isochrones were computed. Results show that simplifying the heart as an isotropic material introduces notable discrepancies in activation patterns and BSPM characteristics. Quantitative assessment using correlation coefficient and relative error metrics confirms that heart anisotropy plays a critical role in generating accurate BSPMs.