Totally self-contained intracardiac pacemaker

Recent developments in miniature long-life power sources and electronics, such as nuclear batteries and integrated circuits make feasible a new generation of pacemakers, the intracardiac pacemaker (IC), i.e, a completely self-contained pacemaker implanted inside the right ventricle by transvenous insertion. Since the IC pacemaker eliminates all leads, problems associated with the leads such as lead breakage or dislocation are also eliminated. Furthermore, since it is feasible to implant and recover the IC pacemaker through a jugular vein using a detachable catheter, the surgery required for implantation or removal is significantly reduced, and since the IC pacemaker can utilize long-life power sources the need for frequent replacement is eliminated. Two versions of the prototype capsule have been implanted in dogs with previously induced complete heart block. A mercury battery-powered capsule exceeded its predicted two months' life, functioning for 66 days with no complications as a result of the presence of the capsule in the right ventricle. A nuclear-powered IC pacemaker utilizing a BETACEL® nuclear battery supplied by Donald W. Douglas Laboratories of the Mc-Donnell Douglas Astronautics Company has recently been implanted, which has a potential life of about five years.