Clinical clues to the causes of large pericardial effusions.

PURPOSE

To examine whether the size of the effusion, the presence of tamponade, and inflammatory signs are useful in determining the causes of moderate or severe pericardial effusions.

SUBJECTS AND METHODS

All echocardiograms performed at a general hospital between January 1990 and April 1996 were screened for pericardial effusion. Patients with moderate (echo-free space of 10 to 20 mm during diastole) or severe (echo-free space >20 mm) effusions were studied.

RESULTS

We identified 322 patients (166 [52%] men, mean [+/- SD] age 56 +/- 17 years [range 15 to 88 years]), 132 (41%) with moderate and 190 (59%) with severe pericardial effusion. The most frequent etiologic diagnoses were acute idiopathic pericarditis (n = 66 [20%]), iatrogenic effusions (n = 50 [16%]), cancer (n = 43 [13%]), and chronic idiopathic pericardial effusion (n = 29 [9%]). In 192 (60%) of the patients, the cause of the effusion was a known medical condition. In the 130 other patients, inflammatory signs were associated with acute idiopathic pericarditis (likelihood ratio = 5. 4, P < 0.001), severe effusions without inflammatory signs or tamponade were associated with chronic idiopathic pericardial effusion (likelihood ratio = 20, P < 0.001), and tamponade without inflammatory signs was associated with malignant effusions (likelihood ratio = 2.9, P < 0.01).

CONCLUSIONS

In many patients, pericardial effusions are due to a known underlying disease or condition. In patients without underlying diseases, inflammatory signs, the size of effusion, and the presence or absence of cardiac tamponade can be helpful in establishing cause.