This thesis develops a new electro-mechanical model based on the model of Rice et al. used to couple the electrophysiological and cardiac models developed in Barcelona Supercomputing Center. This model consists in a system of coupled ordinary differential equations which is solved numerically using matlab and after Fortran 90 languages. Finally the model is implemented into Alya code and coupled with the electrical and mechanical models in order to obtain 3D images of a small piece of cardiac tissue.