A method for non-invasive treatment of cardiac arrhythmias is provided. The method includes acquiring body surface electrical signals at locations on a body surface of a living being from electrodes placed on locations of the body surface, reconstructing three-dimensional heart and torso anatomical models of the living being from an imaging scan, and calculating an electrical activity a throughout three-dimensional volume of the heart by electrocardiogram inverse problem solving based at least in part on the acquired body surface electrical signals and the reconstructed three-dimensional heart and torso anatomical models. The method also includes identifying at least one location of at least one site of origin of a cardiac arrhythmia according to the calculated electrical activity within the heart, and delivering focused energy to the identified at least one location of the at least one site of origin of the cardiac arrhythmia.
