Inferior vena cava plethora with blunted respiratory response: a sensitive echocardiographic sign of cardiac tamponade.

To assess the diagnostic and prognostic value of the respiratory behavior of the inferior vena cava in pericardial effusions, clinical and two-dimensional echocardiographic data of 115 consecutive patients with a moderate or large effusion, including 33 who had cardiac tamponade, were reviewed. Echocardiograms were reviewed for effusion size, inferior vena cava diameter before and after deep inspiration and presence of right atrial and ventricular collapse. For the 83 patients (72%) with less than 50% decrease in inferior vena cava diameter after deep inspiration ("plethora"), inferior vena cava diameter decreased from 2.0 +/- 0.3 to 1.6 +/- 0.4 cm after inspiration (mean +/- SD) (mean decrease 18%). For the 32 patients (28%) without plethora, the diameter decreased from 1.6 +/- 0.5 to 0.6 +/- 0.3 cm (mean decrease 63%). Patients with plethora had significantly higher values for heart rate (111 +/- 21 versus 98 +/- 20 beats/min), pulsus paradoxus (24 +/- 15 versus 12 +/- 4 mm Hg), jugular venous distension (14 +/- 5 versus 8 +/- 3 cm H2O) and right atrial pressure (17 +/- 6 versus 12 +/- 6 mm Hg) and lower values for systolic blood pressure (109 +/- 22 versus 132 +/- 27 mm Hg) (all p less than 0.05) than did patients without plethora. Plethora was present in 58 (92%) of 63 patients who underwent a pericardial drainage procedure, 14 (88%) of 16 who developed constrictive physiology and 11 (92%) of 12 of those whose hospital death was related to pericardial effusion.(ABSTRACT TRUNCATED AT 250 WORDS)