Prognosis of pericarditis after acute myocardial infarction.

Out of 195 patients with acute myocardial infarction, 22 (II 3%) developed a pericardialfriction rub. The diagnosis of the postmyocardial infarction syndrome was made in none of these. The course of the 22 patients with pericarditis was compared with that of a consecutive series of 50 patients without pericarditis. As a group, those with pericarditis had a greater rise in SGOT and higher incidence of arrhythmias and heart block, cardiac failure, and cardiogenic shock. A greater number had high ESR and abnormal chest films. All these differences were significant, but there was no significant difference in the mortality between the two groups. The complications were attributed not to the pericarditis, but to the extensive myocardial damage. Two patients with pericarditis who had been given anticoagulants developed haemopericardium which probably contributed to their death. It is concluded that (a) though pericarditis is indicative of severe myocardial infarction it does not increase the mortality; (b) a friction rub persistingfor 3 days or more should be considered as a bad prognostic sign; and (c) in the presence ofpericarditis in very ill patients with extensive infarction, anticoagulants should be discontinued since there might be a danger of haemopericardium.