The right atrial thrombus: the sword of Damocles with real risk of massive pulmonary embolism.

Cases of 6 patients admitted at the intensive care unit for massive pulmonary embolism are reported. All patients presented with dyspnea, tachypnea, and tachycardia, and 4 were hypotensive and had syncope. Lung ventilation/ perfusion scans revealed perfusion defects in 4 patients. Transthoracic echocardiography (TTE) demonstrated acute cor pulmonale. It also revealed mobile right atrial thrombi in 5 patients, adherent thrombus in the right atrium in 1 patient and patent foramen ovale in 4 patients. Thrombolytic therapy was initiated in 4 patients, and 2 patients received heparin infusion only. Effects of thrombolysis were monitored using bedside TTE during the first 24 hours and in follow-up. The outcome of 4 patients who received thrombolytic therapy was good whereas other 2 patients, who received only heparin, died. Thrombotic mass disappeared 8 to 12 hours after initiation of therapy, and 10 weeks after discharge TTE showed normalized right ventricle dimensions and function in all 4 patients.