THE MAJOR requirements of a cardiac pacemaker are that it be durable and that it be reliable. As the ability to stimulate the heart for prolonged periods is well established, the intrinsically temporary nature of the instruments now in use and the unreliability of the leads, electrodes, and circuit have become a serious limitation to the application of pacer techniques.1,2
Continued, prolonged pacing depends on the maintenance of an electrical output, properly timed, and adequate in amplitude; the maintenance of the receptivity of the heart itself to the applied stimuli and the maintenance of the structural integrity of the pacemaker and its leads.
The major components of an implanted pacemaker assembly are: (1) the power source, (2) the electronic circuit, (3) the wire leads from the pulse generator to the myocardial electrodes, (4) the myocardial electrodes themselves.
Each of the components has been demonstrated to suffer a high rate