This is a thorough, well-written history not only of the pacemaker and internalized defibrillator, but of the cultural implications of the devices. Most of the emphasis is on the pacemaker -- the first fully implantable and miniaturized form of life support. Jeffrey examines how the pacemaker began as a rarely-used lifesaving device and morphed, with the coming of Medicare, into a massively deployed standard of care for elderly people whose heart rhythm systems were wearing out with age. This is a book for people interested in detailed medical and technological history rather than a general interest book. For specialized readers, I recommend it highly. It contains great story of technology unfolding, including the men behind the inventions, like Medtronics founder and inventor Earl Bakken, who used a metronome circuit design from Popular Electronics to cobble together the first portable (but not implantable) pacemaker in 1958. Jeffrey's account is fascinating, but not rah-rah -- he looks at the complex social, political and cultural context in which the devices arose. It was a great background source for a book I'm currently writing, and for an article I wrote for the New York Times magazine in June 2010 called "What Broke My Father's Heart," a family medical memoir examining the moral choices created by devices like the pacemaker near the end of life.
Machines In Our Hearts is an excellent history of the pacemaker and defibrillator. These devices are one of the best examples of the application of technology to medicine. Jeffrey tells the exciting story of their development. I highly recommend it.