The purpose of this study was to evaluate the sensitivity of current echocardiographic criteria in detecting cardiac tamponade in the patient who has undergone cardiovascular surgery. Because the current echocardiographic criteria for tamponade were initially developed and studied predominantly in patients with medical problems, relatively less information is available in patients who have undergone cardiac surgery. Of 848 consecutive patients who underwent cardiovascular surgery, patients were selected for the study if they had clinical or hemodynamic deterioration and had undergone an echocardiogram just before a successful pericardiocentesis or a surgical evacuation of pericardial blood or clot. The echocardiograms were evaluated for evidence of chamber collapse, cardiac motion, Doppler flow variations, and the location and width of pericardial separation. Fourteen patients were identified who met the inclusion criteria (clinical or hemodynamic deterioration, recent echocardiogram, and successful intervention) for cardiac tamponade. The clinical and hemodynamic findings were hypotension (13 patients), low cardiac output (7), low urine output (3), cardiopulmonary arrest (1), elevated central venous pressure (1), and shortness of breath (1). In these patients current echocardiographic criteria were seen infrequently: chamber collapse in the right atrium (6 of 14 patients) and right ventricle (4 of 14); Doppler flow variation (2 of 5); and swinging heart (0 of 15), whereas increased pericardial separation (> or = 10 mm) was seen in all (14 of 14) the patients.(ABSTRACT TRUNCATED AT 250 WORDS)