Ventricular fibrillation and its recurrence in early acute myocardial infarction.

At the initial arrest in 73 consecutive survivors of primary ventricular fibrillation who were seen within 1 h of myocardial infarction, 67% had much less than 2 episodes of ventricular fibrillation and 57% required much less than 2 shocks: only 7% required greater than 10 shocks to correct ventricular fibrillation. 12 (16%) of the 73 had recurrent ventricular fibrillation. The incidence of recurrent ventricular fibrillation, number of recurrences, and interval from the initial episode to recurrent ventricular fibrillation were similar whether the initial episode occurred within the first hour of the onset of symptoms or later. Age, sex, history of previous infarction, site of infarction, adequacy of initial resuscitation, place of arrest, time from onset of symptoms to initial arrest, and delay before initial attempted defibrillation were not significantly related to the recurrence of ventricular fibrillation. The incidence of recurrent ventricular fibrillation among patients seen within 1 h of the onset of symptoms was not greater than among comparable patients seen later.