A lead for use with an implantable cardioverter/defibrillator system is disclosed. In the preferred embodiment, the lead combines a right ventricular endocardial electrode, a superior vena cava electrode and one or more atrial sensing electrodes on a single catheter lead. The distal end of the lead is transvenously implanted, typically through an incision in the cephalic or subclavian vein. The proximal end of the lead is then tunneled below the fascia to the location of the pulse generator. Ventricular sensing and/or pacing electrode(s) may also be included at the distal end of the combined lead to provide ventricular intracardiac electrogram sensing and bradycardia pacing.