1. A method for computing epicardial surface electric potentials based on measured body surface electric potentials, the method comprising: representing at least one geometric relationship between at least one body surface electric potential measuring system and the epicardial surface, as a multidimensional matrix, using a Generalized Minimum Residual (GMRes) method to estimate an inverse of the multidimensional matrix, and, based on the inverse matrix and the measured body surface potentials, determining the epicardial surface electric potentials.