SUCCESSFUL USE OF THE DC EXTERNAL DEFIBRILLATOR AFTER FAILURE OF AN AC EXTERNAL DEFIBRILLATOR.

The opportunity for a clinical comparison of the effectiveness of AC and DC types of external defibrillators in the same patient rarely presents. A postoperative patient developed ventricular fibrillation and was successfully resuscitated by means of closed chest cardiac massage and positive pressure ventilation. Three shocks using an AC external defibrillator did not interrupt the arrhythmia, whereas one shock (150 Wsec.) delivered from a DC external defibrillator resulted in immediate interruption of the ventricular fibrillation. This case lends support to the clinical impression gained in the Vancouver General Hospital that the DC external defibrillator is superior to the AC defibrillator.