Cardiac arrest under age 40: etiology and prognosis.

Between January 1979 and December 1982, 84 patients between the ages of 1 and 39 years presented to the emergency department in a state of cardiac arrest. There were 58 male patients (69%) and 26 female patients (31%) in the group. Presenting rhythms were ventricular fibrillation (37%), asystole (37%), idioventricular rhythm (14%), heart block (4%), bradycardia (4%), ventricular tachycardia (3%), and electromechanical dissociation (3%). Thirty-two percent had bystander CPR. Of 21 patients initially resuscitated (25%), only four (5%) survived to discharge from the hospital. All survivors were neurologically intact. Seventy-five of the 80 patients who died (90%) underwent autopsy. Cause of death in the five remaining patients was inferred from clinical history. Etiologies of the cardiac arrests were the following: toxic exposure or ingestion (26%), atherosclerotic heart disease (23%), undetermined (11%), pulmonary embolism (6%), hemorrhage (6%), epilepsy (2%), cardiomyopathy (7%), myocarditis (2%), pneumonia (4%), and one case each of airway obstruction, asthma, peptic disease, and septic shock. Diverse etiologies should lead to a diagnostic search for reversible conditions in young patients. The prognosis for hospital discharge is poorer in the young population than is reported in our overall cardiac arrest population; however, numbers of neurologically intact survivors are similar in the young and the overall cardiac arrest population.