Case of a floating right atrial thrombus successfully treated with fibrinolysis

Mobile right atrial thrombi are at high risk of causing massive pulmonary embolism and are a medical emergency. This type of thrombus is identified in about 4-18% of pulmonary embolism cases. The presence of a free-floating embolic mass in right atrial or ventricle is often mortal: the death rate can reach 27%. Although surgery is commonly indicated, fibrinolysis is a therapeutic alternative. Here, a 58-year-old man presented to the emergency department for acute dyspnea associated with a painful right leg. Initial exams showed a shunt effect on blood gases with increased brain natriuretic peptide. Transthoracic echography (TTE) found a free-floating thrombus in the right atrium with signs of pulmonary hypertension and right ventricular dysfunction. Bilateral pulmonary embolism was confirmed by computed tomography angiography. Because there were signs of acute cor pulmonale and no contraindications, treatment with systemic fibrinolysis was decided. The treatment was delivered in intensive care unit and a cardiac surgical team was available. Subsequent clinical improvement was observed. TTE follow up at 12 hours revealed complete thrombus dissolution. There were no complications, in particular no hemorrhage. The patient was discharged after eleven days. At 6 months of follow-up, outcomes with oral anticoagulation therapy were satisfactory. Scintigraphy found good symmetrical perfusion of both lungs with stackable ventilation. TTE at 1 year showed preserved left and right ventricular function with no sign of pulmonary arterial hypertension and no thrombus recurrence. Systemic fibrinolysis appears to be a good alternative to surgery in this case.