Ventricular Defibrillation of a 341 kg Horse Using Precordial Electrodes

Using a specially constructed 5000 watt-second defibrillator, trans-chest ventricular defibrillation was achieved in a 341 kg horse. Minimum peak electrical current flow used to defibrillate was 280 amperes; maximum peak current was 300 amperes. Circulatory support by external cardiac compression was necessary for a 25 minute period after defibrillation. Resumption of cardiac function was achieved only after intravenous administration of epinephine, calcium chloride and dexamethazone. To the authors' knowledge, this is the largest animal in which electrical ventricular defibrillation has been reported.