Simulation by a digital computer of propagated excitation in the ventricular myocardium has been accomplished. Experience with the program in normal conduction and in one example of abnormal conduction, an extrasystole, is presented. Results of the simulation process were in harmony with observations in animal experiments. This justifies attempts to apply this scheme to the analysis of abnormal ventricular excitation caused by other disturbances.A crucial role of the Purkinje network in determining the course of excitation spread was recognized in the simulated process of both normal beats and extrasystoles. New knowledge is expected from this scheme when applied to other types of abnormal excitation.The possibility of combining the scheme with a method of reconstruction of QRS complexes by means of “transfer impedance” values was pointed out.