Unusual biatrial thrombus in mitral stenosis

Excerpt

A 77-year-old man was admitted to our hospital with mild shortness of breath on exertion. For several years, he has been diagnosed as having mitral stenosis and complicating chronic heart failure. On physical examination his blood pressure was 125/75 mmHg with irregular pulse. ECG showed atrial fibrillation at a rate of 80–95 beats/min. Although he was given anticoagulant such as warfarin, the international normalized ratio (INR) of 1.2–1.4 was not sufficient. Brain computed tomography (CT) results were suggestive of old cerebral infarction, although thoracoabdominal CT did not show any signs of embolism in other organs. Transthoracic echocardiogram documented severe mitral stenosis with a valve area of 0.7 mm² and incidentally revealed abnormal mass-like image features in both atria. The tricuspid valve had mild regurgitation without stenosis. Calculated right ventricular systolic pressure was estimated to be 35 mmHg, suggesting the presence of mild pulmonary hypertension. Transesophageal echocardiography (TEE) confirmed the presence of a huge thrombus-like image feature (40 × 19 mm) in the left atrial appendage (LAA) extending to the dilated left atrium (Fig. 1a). Under these conditions, LAA emptying velocity was significantly reduced. Interestingly, another mobile mass image feature (25 × 20 mm) was detected in the lateral wall of dilated right atrium (Fig. 1b), and was considered to be tumor such as lipoma. The patient underwent mitral valve replacement and removal of biatrial abnormal masses, which were finally diagnosed as huge thrombi by pathological examination (Fig. 2a, b).

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