Abstract: The invention includes an insulated, fatigue-resistant conductor formed of a conductive wire, a polymeric insulative sleeve having inner and outer layers, and a shape memory alloy (SMA) element disposed between the two layers. The SMA has a preferred thickness between 2 and 50 microns, an undeformed austentitic state, an Af between about −10° C. and 35C., a pseudoelasticity character above its Af, and demonstrates a stress/strain recovery greater than 3% above its Af. Also disclosed is a method of forming the conductor, and a pacemaker which uses conductor as leads.