Abstract: Pacemaker for the stimulation of the human heart having three electrodes or two electrodes, with the first electrode connected to the right atrium, the second electrode connected to the right ventricle and the third electrode connected to the said right ventricle. The pacemaker is programmed so that there is first stimulation of the right atrium by means of the first electrode, then there is second stimulation of the right ventricle by means of the second electrode with an interval function of the programmed AV delay (50-400 msec) and with a voltage not exceeding 80-90% of the threshold potential, and finally there is third stimulation, again of the right ventricle by means of the third electrode with a voltage that conforms with Safety Margin rules and at a second stimulation time interval comprised between 50 msec and 300 msec.