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Early history of defibrillation

WhenQueen Victoria died in 1901, newspapers reflected on the glorious accomplishments of her reign: ‘Steam and electricity have emerged from the realm of dreams, passed all the stages of experiment, and become the regulated and completely disciplined servants ofmankind.’ In reality, though, as the world ticked over into the 20th century, industrial electricity was still in its infancy and themedical world was only on the cusp of understanding its potential risks and benefits. Electricity first became commercially available in the 1870s when practical generators were developed. The increasing use of electricity, both direct current (DC) and alternating current (AC), resulted in many accidental deaths, particularly among power company employees, but the mechanism of death remained elusive. There were many theories—from a loss of magnetic properties in arterial blood to suffocation and heart failure – but insufficient evidence to support any of them. It was hoped that the first legal electrocution, the death of William Kemmler in an electric chair on 6 August 1890, would provide some answers, but despite the presence of 12 physicians at the execution and an extensive autopsy, the situation remained largely unexplained. The question was finally answered in 1899, when independent research by Italian physiologists Jean Louis Prevost and Frederic Battelli, and RH Cunningham of Columbia University, demonstrated that strong electric shocks stopped the hearts of experimental animals. Additionally, they observed that weak shocks caused ventricular fibrillation, which was also fatal. Prevost and Battelli discovered that some of the animals with ventricular fibrillation were restored to sinus rhythm by applying further current through electrodes in the mouth and small intestine. As they were unable to explain this phenomenon, or consistently replicate it, this first successful internal defibrillation went relatively unnoticed. At the time, ventricular fibrillation was thought to occur only in animals but John McWilliam, also writing in 1899, suggested that it may also be a cause of death in humans: ‘It is hardly to be expected that such a widespread and probably universal feature of mammalian cardiac action should be unrepresented in the case of man.’ Augustus Desiré Waller published the first account of a recorded electrocardiograph in 1887, paving the way for Willem Einthoven to develop it into a practical clinical tool. By the 1920s, many arrhythmias had been described and, as the physiology of the heart became clearer, various researchers noted that there appeared to be a refractory period in the cardiac cycle where the ventricles were more susceptible to ventricular fibrillation from an electric shock. In 1940, Carl Wiggers and René Wégria demonstrated this conclusively, establishing that a brief electric shock ‘induces fibrillation only when the shocks fall during the vulnerable period of late systole.’ Cover photo. Early Australian defibrillator. Image courtesy of the Geoffrey Kaye Museum of Anaesthetic History, VGKM4612.