Pericardial clot after open heart surgery: its specific localization and haemodynamics

Transoesophageal echocardiography disclosed a localized pericardialblood clot compressing the right atrium (RA) and/or right ventricle(RV) in 15 patients suffering from low cardiac output failuresoon after open-heart surgery. The left ventricular end-diastolicdiameter was small (38.4 ± 10.1 mm) and its fractionalshortening normal (34.9 ± 10.2%). These findings suggestedcardiac tamponade as a result of pericardial clot. However,the ‘y’ trough of the RA pressure tracing was prominent,which is not characteristic of typical cardiac tamponade, butrather of constrictive pericarditis. This implies thereforethat the pathophysiology of cardiac tamponade by pericardialclot differs from that of tamponade by fluid. Emergency open-chestremoval of the pericardial clot was performed in seven patients,with good results. Pericardial clot produces low cardiac outputsoon after open-heart surgery, but its location is specificand its haemodynamics are not characteristic of cardiac tamponade.