The isotopic cardiac pacer: a ten-year experience.

In the past, the battery has been the main cause of pacemaker failure. The isotopic-powered cardiac pacemaker theoretically should provide greater reliability and longevity than pacemakers powered by chemical batteries. We studied 79 isotopic pacemakers in 75 patients for up to 10 years. Four types of Plutonium 238 powered pacemakers were studied. They included 5 VOO, 51 VVI, 14 VVIP, and 9 VVIM pacemakers. A more diverse group of 93 VVI, VVIP and VVIM pacemakers, powered by chemical batteries, were studied as controls. During the course of study the mercury zinc battery has become obsolete. The increased longevity of the lithium battery, at first very promising, has been compromised by the demands firstly of smaller size, and later of more complex circuits. The longevity and reliability of the isotopic pacemakers has been found to be superior to pacemakers powered by chemical batteries. The isotopic fuel cell, because of its greater longevity, may be needed for the increasingly complex circuits required for dual chamber pacemakers, functioning for the control of bradyarrhythmia alone, or combined with tachyarrhythmia control.