Abstract: A method of simulating electrical propagation in the heart muscle on a computing device having a processor and a memory includes providing a structural representation of a heart muscle. The structural representation includes a plurality of tissue elements. The plurality of tissue elements have a shape corresponding to shape of a heart muscle. The method includes storing a model of electric potential propagation through the structural representation in the memory. The model includes a piecewise linear equation describing electrical activity within each tissue element and a difference equation describing conduction from one of the tissue elements to an adjacent tissue element. The method also includes providing a first set of tunable parameters for inclusion in the piecewise linear equation and a second tunable parameter for inclusion in the difference equation. The method further includes tuning the first set of tunable parameters and the second tunable parameter in the model.