Clinical significance of pericardial effusion associated with pericarditis in acute Q-wave anterior myocardial infarction.

To elucidate the incidence and clinical factors related to the occurrence of pericardial effusion in infarction-associated pericarditis, 303 consecutive patients with their first Q-wave anterior myocardial infarction were examined carefully by means of auscultation, echocardiography, chest radiography, and hemodynamic monitoring. During the first 3 days, a pericardial rub was detected in 65 patients and was absent in 238 patients. Among the 65 patients with pericardial rub, pericardial effusion was present in 27 patients (group 1) and was absent in 38 patients (group 2). Although there were no significant differences in cardiac output, pulmonary artery wedge pressure and right atrial pressure between the two groups, patients in group 1 had significantly more left ventricular segments with advanced asynergy and higher radiographic scores (diffuse interstitial infiltrate or alveolar infiltrate) compared with those in group 2. Thus, pericardial effusion and increased extravascular lung water in infarction-associated pericarditis were not caused by left ventricular failure but by other mechanisms reflecting a larger infarct.