Correlation between clinical and Doppler echocardiographic findings in patients with moderate and large pericardial effusion: implications for the diagnosis of cardiac tamponade.

BACKGROUND: Clinical data are of unquestionable value for management purposes in cardiac tamponade, whereas the precise value of Doppler echocardiographic findings is not yet fully understood. We aimed to prospectively assess the correlation between clinical and Doppler echocardiographic signs in the diagnosis of cardiac tamponade in a large series of patients with pericardial effusion.

METHODS: During a 2-year period, all patients with moderate and large pericardial effusion were prospectively assessed. The presence of clinical findings suggesting cardiac tamponade, right cardiac chamber collapse on the echocardiogram, and Doppler venous flow pattern were simultaneously evaluated.

RESULTS: One hundred ten patients were included (49 with moderate and 61 with large effusions). Thirty-eight patients showed clinical features suggestive of cardiac tamponade and 72 did not. In patients with clinical tamponade, 90% had collapse of one or more right cardiac chambers, but 4 (10%) did not have any collapse. Venous flow was analyzable in 63%, suggesting tamponade in 75% of the patients. In patients without clinical tamponade, 34% showed collapse of one or more cardiac chambers. Venous flow pattern was normal in 80%, inconclusive in 11%, and only suggestive of tamponade in 9% of patients. If clinical features of tamponade were considered the diagnostic standard, sensitivity and specificity would be 90% and 65% for the presence of any collapse, 68% and 66% for right atrial collapse, 60% and 90% for right ventricular collapse, and 45% and 92% for simultaneous collapse of both chambers. Sensitivity and specificity of venous flow analysis would be 75% and 91%, respectively.

CONCLUSIONS: There is a good correlation between absence of collapse and absence of tamponade, but the correlation is poor between collapse and tamponade. Abnormal venous flow has a good correlation with clinical features of tamponade, with a higher sensitivity than right ventricular collapse and a much higher specificity than right atrial collapse.