Effect of Electric Shock on the Heart

A joint investigation of the effects of electric shock on the heart, extending over a period of several years, has yielded many significant results. It has been found that electric shock may derange heart action causing ventricular fibrillation without damage to heart tissue, but resulting in death within a few minutes. This heart effect establishes the maximum current that may be withstood safely for short durations. Threshold fibrillating currents were determined for different conditions of pathway, frequency, and duration using numerous anesthetized animals of different species, comparable in size with man. The discovery was made that the heart is susceptible for only about 20 per cent of its cycle. Successful recoveries from ventricular fibrillation were obtained with large animals of several species by high intensity shocks of short duration.