Cardioversion following open-heart valvular surgery.

At the turn of the century, Prevost and.Battelli (1899) observed that direct application to the dog's heartofa strongcurrentofshort durationstopped ven- tricular fibrillation. More than 30 years later, Hook- er, Kouwenhoven, and Langworthy (1933) began a series of experiments utilizing an alternating current directly to the animal heart. This and subsequent studies (Ferris et al., 1936; Wiggers, 1940, etc.) laid the basis for successful defibrillation of a human heart by Beck, Pritchard, and Feil in 1947. How- ever, it was not until 1956 that external defibrillation became a practicalprocedure And it is since the initiation by Lown, Amarasingham, and Neuman into the use of a synchronized direct current in 1962 that the procedure has gained a wide popularity.