Cystic Cardiac Mass in the Left Atrium

A 71-year-old man was admitted to our hospital with a 6-month history of progressive dyspnea on exertion. He had diabetes mellitus on medications. On physical examination, his pulse rate was 90 bpm and blood pressure was 100/70 mm Hg. A low-frequency diastolic heart murmur was heard at the apex without systolic murmur. Blood chemistry levels were within normal range. The 12-lead ECG showed a sinus rhythm with left atrium (LA) enlargement. Chest X-ray showed no abnormal finding. Transthoracic echocardiography revealed a mobile, pedunculated mass (5.1×3.2 cm) in the LA, which was attached to the interatrial septum (Figure 1 and online-only Data Supplement Movies I, II, and III). The …