Ventricular fibrillation is a state of cardiac arrhythmia in which the individual heart muscles contract in a random, uncoordinated way. The heart appears to shiver, and blood circulation ceases. Ventricular fibrillation is fatal unless an electric shock is applied within minutes to restore normal heart contraction. As early as 1899, French physiologists, Jean Louis Prevost and Frederic Battelli were able to stop ventricular fibrillation in a dog by applying an electric shock to the animal's exposed heart. In 1930, William B. Kouwenhoven, an American electrical engineer at Johns Hopkins University, developed with colleagues a closed-chest defibrillator that sent alternating current (AC) electrical shocks to the heart through electrodes placed on a dog's chest. In 1947, Claude Beck, professor of surgery at Case Western Reserve University, first successfully resuscitated a human patient by internal cardiac massage and electrical defibrillation; American cardiologist Paul Zoll applied AC defibrillator to human patients in 1961; and the...