During the first three years in operating a comprehensive system for the management of out-of-hospital medical emergencies, 146 patients were resuscitated from ventricular fibrillation, hospitalized, and discharged home. The diagnosis of acute transmural myocardial infarction associated with the episode of ventricular fibrillation was confirmed in only 17% of the patients. The presence of myocardial necrosis, based on either evidence of new transmural infarction or LDH-isoenzyme criteria was established in 49.5% of the patients. During the follow-up period, averaging 418 days, 43 of the 146 patients died. Thirty-four of the 43 deaths occurred suddenly outside the hospital. Patients whose aborted sudden cardiac death was associated with acute transmural infarction had a mortality rate of 14% after two years of follow-up. In contrast, patients without evidence of acute myocardial necrosis had a high mortality rate — 47% at two years.
It is concluded that: 1) out-of-hospital ventricular fibrillation is common and treatable; 2) the phenomenon of sudden cardiac death should not be equated with acute myocardial infarction; 3) patients resuscitated from ventricular fibrillation without associated acute myocardial infarction are prone to sudden death — most likely from ventricular fibrillation.