Huge atrial thrombus causing massive pulmonary and paradoxical embolism via patent foramen ovale.

n August 2003, a 44-year-old woman suffering from postpartum dilated cardiomyopathy was referred to our coronary care unit with the complaint of sudden-onset dyspnea. She had been monitored since 1995 because of a diagnosis of primary antiphospholipid antibody syndrome. On admission to our hospital, the patient was in respiratory distress, severely cyanotic and hypotensive. Upon physical examination, her arterial blood pressure was severely depressed (70/40 mmHg), her heart rate was 110 beats/min, and her respiration rate was 35/min. Arterial blood gases demonstrated a PaO2 of 40 mmHg and PaCO2 of 35 mmHg, with respiratory alkalosis. Therefore, she emergently underwent mechanical ventilation. Her electrocardiogram showed sinus tachycardia at a rate of 110 beats/min, poor R wave progression in all precordial leads, Q waves in lead III, and deep S waves in lead I. We immediately performed bedside transthoracic (TTE) and transesophageal (TEE) echocardiographic studies, which revealed a large mobile serpentine thrombus, entrapped in a patent foramen ovale (PFO), in the right atrium. The thrombus also extended into the left atrium and protruded into the right ventricle during the diastolic phase of the cardiac cycle (Figs. 1 and 2). Significant tricuspid regurgitation was observed; from the measurement of tricuspid regurgitant velocity, we estimated pulmonary artery systolic pressure to be 60 mmHg. Surgical thrombectomy was not attempted due to the patient’s hemodynamic instability and to the development of right hemiparesis from a presumed paradoxical embolus. The patient died despite all resuscitative attempts.