Milestones:First External Cardiac Pacemaker, 1950
First External Cardiac Pacemaker, 1950
In 1950, in Room 64 of the Bantling Institute of the University of Toronto, Drs. Wilfred Bigelow and John Callaghan successfully paced the heart of a dog using an external electronic pacemaker-defibrillator having implanted electrodes. The device was developed by Dr. John Hopps at the National Research Council of Canada. This pioneering work led to the use of cardiac pacemakers in humans and helped establish the importance of electronic devices in medicine.
The plaque may be viewed at the front entrance of the C. H. Best Institute, 112 College Street, Toronto, Ontario, Canada.
According to a medical study published by Barber and Madden, up until 1945, the only successful operative cases of cardiac standstill had been treated with cardiac massage and intraventricular injection of adrenaline (33% of 143 such cases survived). Callaghan and Bigelow also report on the work of Hyman (1932) who used a cranked generator and needle inserted into the right auricular wall of guinea pigs to restart their stopped hearts. Also of note is that Sweet restarted to human hearts during operation by applying electrical current to the sino-auricular nodal region. Mark Lidwell from Australia reported at the Third Congress of the Australian Medical Society in 1929 the successful use of electrical stimulation with alternating current in 1928 to restart the heart of a child born in cardiac arrest.
Jack A. Hopps developed a simplified circuit and a portable model Pacemaker-Defibrilator which was used to continously stimulate stopped hearts to beat at a pre-set rate, or to induce spontaneous heart beating after which the heart continued to beat normally. These beats were inuced in dogs and rabbits through an inter-cardiac catheter electrode, rather than other approaches (e.g. needle electrodes) tried previously. This device was built in limited numbers commercially by Smith and Stone co., Ltd, Georgetown, Ontario, Canada.
Subsequent work by Zoll in 1951 (the PM-65 pacemaker) led to successful clinical use. In 1955, a patient with cardiac arrest was treated and had his heart pulse restored in Montreal using a Zoll device built by Electrodyne Company, Norwood, Massachusetts, U.S.A. In 1956, Aubrey Leatham and Geoffrey Davies developed an external stimulator with which to resuscitate patients with heart block.
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