Open-Heart Surgery and the Artificial Pacemaker
By the early 1950s, despite Dr. Gordon Murray's obvious successes, a younger crop of surgeons at the TGH had started to approach heart surgery in new ways, particularly moving into open-heart surgery. In November 1955, Raymond Heimbecker, a student of Murray's, proceeded with the first successful human heart valve transplant on a 25-year-old man with a leaky aortic valve.
Another young surgeon at the TGH and a student of Best's, William Bigelow, pioneered the possibilities of open-heart surgery with the use of hypothermia. Beginning in 1947, and basing his work on clinical experience with frostbite, Bigelow experimented with lowering the body temperature to stop blood circulation, allowing the surgeon some time to operate cleanly on the heart. After success with monkeys, he began to try this procedure on human patients in 1953 and by 1960 had performed fifty "deep-freeze operations" at the TGH using blankets with cold-water cooling coils. This type of operation only allowed a short time to operate on the heart and was soon supplanted with the development of heart-lung machines.
However, Bigelow’s work gave rise to a more lasting discovery: the artificial cardiac pacemaker. The concept of a pacemaker to regulate the heartbeat had originated in 1932 but had not been pursued. Curious about why the hearts of some of his research animals stopped while in hypothermic states, Bigelow discovered that short, specific and repeated electrical stimulation could simulate how the heartbeat is controlled naturally. In 1950, Bigelow and several colleagues built a pacemaker that was about the size of a cabinet radio and they used it to regulate the heartbeat of dogs. However, it was not until about 1960, with the invention of the transistor, that a pacemaker could be made small enough to be implanted inside a patient.
Another young surgeon at the TGH and a student of Best's, William Bigelow, pioneered the possibilities of open-heart surgery with the use of hypothermia. Beginning in 1947, and basing his work on clinical experience with frostbite, Bigelow experimented with lowering the body temperature to stop blood circulation, allowing the surgeon some time to operate cleanly on the heart. After success with monkeys, he began to try this procedure on human patients in 1953 and by 1960 had performed fifty "deep-freeze operations" at the TGH using blankets with cold-water cooling coils. This type of operation only allowed a short time to operate on the heart and was soon supplanted with the development of heart-lung machines.
However, Bigelow’s work gave rise to a more lasting discovery: the artificial cardiac pacemaker. The concept of a pacemaker to regulate the heartbeat had originated in 1932 but had not been pursued. Curious about why the hearts of some of his research animals stopped while in hypothermic states, Bigelow discovered that short, specific and repeated electrical stimulation could simulate how the heartbeat is controlled naturally. In 1950, Bigelow and several colleagues built a pacemaker that was about the size of a cabinet radio and they used it to regulate the heartbeat of dogs. However, it was not until about 1960, with the invention of the transistor, that a pacemaker could be made small enough to be implanted inside a patient.