Ventricular Fibrillation

Abstract

ELECTRIC shock is widely employed for emergency treatment of ventricular fibrillation and reversion of other arrhythmias. Alternating current defibrillators, delivering relatively long duration 50- or 60-cycle shocks, are being replaced by condenser discharge equipment delivering short direct current shocks. The latter are popular because they show improved functional design and they incorporate oscilloscopes, pacemakers, and synchronizers in a single compact unit. Although there are now outspoken advocates for both AC and DC devices, surprisingly little information is available in the literature to permit a basic comparison. This report is an attempt not only to compare a 3- to 4-millisecond (msec) DC shock with a 75- to 100-msec AC shock both at normal temperature of 37 C (98.6 F) and in moderate hypothermia (25 C) (77 F) but also to contrast these modalities with chemical reversion by means of potassium citrate injected into the ascending aorta. To minimize errors in energy