Atypical presentations and echocardiographic findings in patients with cardiac tamponade occurring early and late after cardiac surgery.

Cardiac tamponade, a potentially lethal complication following cardiac surgery, may present either early or late postoperatively and may be difficult to diagnose due to atypical clinical, hemodynamic, or echocardiographic findings. To determine the frequency and clinical features of postoperative cardiac tamponade, we performed a review of 510 consecutive patients who underwent cardiac surgery. The incidence of postoperative cardiac tamponade was 2.0 percent (10/510 patients) and occurred following valvular, bypass, and aortic surgery. Nine of ten patients had either atypical clinical, hemodynamic, and/or echocardiographic findings. The diagnosis of tamponade was made 1 to 30 days (mean = 8.5 days) postoperatively. Presenting symptoms were often mild and nonspecific. Classic signs including hypotension, pulsus paradoxus greater than 12 mm Hg, and elevated jugular venous pressure were present in 7, 6, and 5 patients, respectively. Right heart hemodynamics revealed elevated and equalized diastolic pressures in three of six patients. Two-dimensional echocardiography revealed selective compression of the left ventricle (LV) (four patients), right ventricle (RV) (one patient), left atrium (LA)/RV (one patient), LA/LV (one patient), LA/LV/RV (one patient), all four chambers (one patient), and no diastolic collapse of any chamber (one patient). There was often an absence of anterior pericardial fluid (six patients) with tethering of a portion of the RV to the chest wall anteriorly (five patients). Coagulation parameters were "supratherapeutic" in only three of eight patients who were receiving systemic anticoagulants at the time of diagnosis. The initial diagnosis was confused with congestive heart failure in one patient, pulmonary embolism in three patients, acute myocardial infarction in two patients, and sepsis in one patient. Eight of ten patients survived; all of these patients underwent surgical removal of fluid and/or hematoma in the operating room. We conclude that postoperative tamponade after cardiac surgery may have varied clinical and hemodynamic presentations, often due to selective chamber compression by loculated fluid or clot. Due to its frequently atypical features and presentation that may simulate other disorders, the diagnosis of tamponade should be considered whenever hemodynamic deterioration or signs of low output failure occur in the postcardiotomy patient.