Echocardiographic detection of pulmonary embolism in transit: implications for institution of thrombolytic therapy.

Right atrial or ventricular thrombi in patients with pulmonary embolism are emboli in transit and are a medical emergency because they are associated with a high mortality rate when treated conservatively with anticoagulation. The current standard therapy is less well accepted because of the risk of clot fragmentation and distal embolization. A case in which an unsuspected right ventricular thrombus was diagnosed by echocardiography is reported. This findings led to treatment with streptokinase (250,000 U, followed by 100,000 U/h for 24 h). Clinical improvement was rapidly obtained and the thrombus disappeared 10 h after the initial study. There was no complication. The case illustrates the utility of two-dimensional enchocardiography in the evaluation of patients with pulmonary embolic disease and the efficacy and safety of thrombolytic therapy in the treatment of pulmonary embolism in transit.