Radioisotope Powered Cardiac Pacemakers

Over 50, 000 implantable cardiac pacemakers are in use to rehabilitate patients with heart block. The chemical batteries powering these pacemakers usually fail within a few years. A variety of nuclear batteries, with the potential of providing long-lived (10 - 20 years) pacemaker power, are under development. This paper reviews the status of this development. Nuclear-powered pacemakers have reached the stage of clinical evaluation. Their cost, although initially high, is not prohibitive. The primary problem inhibiting widespread application is the maintenance of fuel capsule integrity under all creditable conditions.