of Simulated and Ex

a three-dimensional phenomena. Until high resolution three-dimensional mapping techniques are sufficiently advanced, the study of wavefront conduction in the heart will need models that can relate the measured local and global electric fields to the intrinsic transmembrane po-tential and currents in three dimensions. Ideally, the re-lationship between model and experiment should be as more predictive than those using generic properties and thus in combination with experimental data will provide information about intramural activity that cannot be di-rectly measured. In this article, we validate an approach to directly relate a model of wavefront conduction in a three-dimensional section of the left ventricle with high reso-lution experimental measurements recorded from the epi-cardial surface of in vivo hearts. Properties are obtained from the analysis of pace-mapping data and from MRI diffusion tensor imaging of the section of the heart underAddress all correspondence to Craig S. Henriquez, PhD, 136 Hud