The pacemaker (1) has a set of electrodes (2, 2a-2d) such as feedable catheter, a contact plug (8), and a set of electrical counter-contacts (13, 14) that is arranged with two contact regions (11, 12) arranged at the external pacemaker by a wire. A set of defibrillations and/or cardiovascular pulses is transmitted to the set of electrodes. A defibrillator and/or a cardioverter are arranged for taking the output of the defibrillations and/or cardiovascular pulses for providing a defibrillation function.