Pericardial effusion as an early complication of acute myocardial infarction.

Two days after an acute myocardial infarction, a patient developed pleuropericarditis. A negative lung scan and echocardiographic evidence of pericardial effusion were instrumental in making the diagnosis. Steroid therapy led to a dramatic resolution of the signs and symptoms. Pericardial effusion is usually a late complication of myocardial infarction (Dressler's syndrome), but the increasing use of echocardiography may demonstrate that it occurs early in the course.