Sudden cardiac death: identifying and managing the patient at risk.

When ventricular fibrillation is not associated with a myocardial infarction, the tendency is for recurrence, whereas ventricular fibrillation during the acute phase of infarction may not adversely affect the prognosis. The treatment of ventricular dysrhythmias is mandatory for those who have experienced primary ventricular fibrillation without evidence of acute myocardial infarction. This group is at highest risk for sudden cardiac death.