Our purpose is to assess different methods for choosing the regularization parameter combined with the Method of Fundamental Solutions (MFS) for solving the electrocar-diography imaging (ECGi) inverse problem but also to assess their sensitivity to the nature of recorded signals. Results are provided using LV, RV and bi-ventricular pacing experiments performed in an ex-vivo pig heart. In the experiment , some electrodes are too close to the pericardium so that they seem to be measuring monophasic action potential signals (MAPs) rather then extracellular epicardial potential. The electrodes suspected to measure MAPs are identified by thresholding the epicardial potential in the plateau phase. This leads to compare the computed epi-cardial potential to measurement results with and without considering these electrodes measurements. Removing the MAPs electrodes improves the quality of the RE and CC by at least 5%. Results show that the Generalized Cross Validation (GCV) approach provides the best results in the three pacing cases.