In a cardiac stimulating device, an infection control current is generated and applied to a subject in whom a medical device is implanted by completing a circuit including an entirely electrically conductive exterior of a housing of the device, an electrode carried by an electrode lead of the device, and an electrically conductive surface of a proximal portion of the electrode lead, extending from the housing to a location, after implantation, situated beyond entry of the electrode lead into the venous system and before entry of the electrode lead into the superior vena cava. The infection control current can be a current with a square waveform, and the circuit can be completed at selected times, such as only during the refractory period of the subject's heart.