Thrombus entrapped in a patent foramen ovale, causing only vague symptoms.

Patent foramen ovale provides a passage from venous circulation to arterial circulation. This may allow passage of a thrombus formed in the venous system into the systemic circulation. We present a case in which a thrombus was entrapped in a patent foramen ovale. A 45-year-old woman presented with complaints of atypical chest pain and pretibial edema. Transthoracic echocardiography showed normal systolic function and grade I diastolic dysfunction. Pulmonary artery pressure was 43 mmHg. There was a mobile multilobular mass in the right atrium, attached to the interatrial septum via a thin pedicle. Transesophageal echocardiography showed a biatrial mass. It was 7-10 mm thick, multilobular, homogeneously echogenic, and highly mobile. It passed through the patent foramen ovale into the left atrium. The left atrial part was 6-8 mm thick, relatively shorter, and less mobile. The patient denied any symptoms related to a cerebrovascular accident. Heparin was initiated and an urgent operation was decided. Intraoperative transesophageal echocardiography showed that the mass was a thrombus which had become smaller due to anticoagulation. She had no neurologic symptoms postoperatively. Venous Doppler examination revealed deep vein thrombosis and warfarin was started.