A sterile, implantable flexible wire with an electrode, insulated with non-conductive material except at its ends, which serves as an electrical conductor to transmit pacing impulses from an implanted pacemaker to the heart. It may also transmit electrical responses from the heart back to the pacemaker; it is not intended to conduct defibrillation impulses. The electrode end is normally implanted in the outer surface of the heart (epicardium) in close contact to the wall of one of the chambers of the heart (endocardium), and the other end is connected to the pacemaker. It may be impregnated with a steroid (e.g., dexamethasone) intended to elute into the tissues to reduce inflammation.