A lead assembly for a body implantable medical system adapted to transmit electrical signals between proximal and distal end portions of the lead assembly to thereby stimulate selected body tissue includes an electrical conductor, an insulative sheath composed of silicone or polyurethane covering the conductor, an electrical connector coupled to the proximal end of the conductor for releasable attachment to a stimulating pulse generator and a distal electrode coupled to the distal end of the conductor. The distal electrode has an outer surface generally coaxial with the lead assembly and facing transversely of the longitudinal axis of the lead assembly and generally parallel to the selected body tissue intended for stimulation. The outer surface of the distal electrode is composed of a biocompatible metallic alloy and includes a layer of a material that exhibits low polarization and thereby enhances the electrical efficacy of the electrode.