Machines in Our Hearts: The Cardiac Pacemaker, the Implantable Defibrillator, and American Health Care (review)

On October 8, 1958, a Swedish man named Arne Larsson received the first implantable pacemaker. He was suffering from bradyarrhythmia, a heart that beat too slowly, which in its natural state would have left him weak, stuporous, and liable to fainting spells. Larsson received twenty-six pacemakers over the next forty-three years, long outliving the few months he would likely have had without this new "machine in his heart." Although now surpassed in the public and medical imagination by implantable defibrillators and still-experimental artificial hearts, the pacemaker is a central medical technology of the twentieth century, which still stands as a model of a small, replaceable adjunct to human physiology—a machine both lifesaving and easily forgotten. Pacemakers stand in stark contrast to other efforts to replace or augment failing organs. Technologies such as renal dialysis and mechanical ventilators remain based in hospitals, acting as halfway measures that create a dependence starkly circumscribing the recipients' lives, and frequently signaling their end.

Jeffrey therefore tells a story of profound significance, one of medical practice and industrial research. Relying on a careful reading of the medical literature, interviews with pacemaker recipients, and oral histories with industrial and academic scientists, cardiologists, and surgeons, Jeffrey examines both the experience of pacing and the "heart rhythm management" industry.

The narrative follows the technological innovations and business strategies of the manufacturers. The dominant strategy was to resist the commodification of pacemakers, with its attendant reduction in prices and profits, by continually adding new features, new designs, and refinements to better imitate nature. The strategy of continuous innovation had risks, however. Firms had to choose in the 1970s, for example, between the acceptance of new programmable microprocessors and a traditional reliance on custom-built circuits. Some firms chose microprocessors for their flexibility, athough they suffered from reduced battery life that necessitated more frequent surgical replacements. Others chose custom circuits—even though they, too, felt that it was the less "innovative" choice. Their concerns were about the reliability of both hardware from outside suppliers and software that could contain bugs that might lead to the abrupt cessation of function.

Jeffrey tells a story of rising expectations, from the original hope of some cardiologists for a machine that they could use in the hospital for a few days to get a patient through a difficult episode to a reliable, implantable device that would sustain the patient for years. Once implantable pacemakers were commonplace "it was no longer enough to keep patients alive and give them the daily existence of semi-invalids. Furman and others believed that it ought to be possible for cardiac pacing to bring many patients back to something approximating good health" (p. 221). The "pacemaker syndrome" of occasional lethargy, breathlessness, and fainting that occurred when the heart's atria and ventricles were not coordinated, and consequently backed blood up into the lungs and veins, went from being an unavoidable side-effect to an unacceptable limitation—to be banished by more advanced, physiologic devices.

Although Jeffrey concentrates on the pacemaker in the United States, he acknowledges that both the science and industry of cardiac pacemakers is international in scope. What he lacks in international perspective, however, he makes up in analysis of the financing of health care in the United States. He makes the case that single-chamber pacing of the ventricles continued to be the most common method for almost a decade after the more physiologic dual-chamber (atrial and ventricular) pacers became available both because physicians found the more complex new devices difficult to understand and use, but also because of reduced payments from the federal Medicare program for the elderly.

Machines in Our Hearts is an important contribution to the history...