In an example, an n-dimensional method of fundamental solution (MFS) is used to compute reconstructed electrical activity on a cardiac envelope based on geometry data and electrical data, where n is a positive integer greater than three. The electrical data represents electrical activity measured non-invasively from a plurality of locations distributed on a body surface of a patient, and the geometry data represents three-dimensional body surface geometry for the locations distributed on the body surface where the electrical activity is measured and three-dimensional heart geometry for the cardiac envelope.
