Pericardial Effusion as a Consequence of Acute Myocardial Infarction.

Pericarditis is a common complication of acute myocardial infarction (MI). Its incidence during the first few days after acute MI is 24%-43% when echocardiographic criteria are used, whereas the frequency of clinical pericarditis is much less (from 5% for all acute MIs to 21% for anterior Q wave MIs). Clinical, electrocardiographic findings are discussed. Effusions are mostly small, and the resolution is frequently slow, lasting 1-18 months. Tamponade is extremely rare in the absence of cardiac rupture. Q wave MIs (especially anterior) are more frequently accompanied by pericardial effusion. The prognostic significance of echocardiographically proved pericarditis is questionable.