Large left atrial thrombus mimicking atrial myxoma: successful treatment with anticoagulant therapy.

Left atrial masses, namely thrombi or myxomas, are confidently diagnosed by means of two-dimensional echo-cardiography' 11. By transthoracic echocardiography, diagnostic specifi-city is reported to be high, while sensitivity is relatively low* \ Trans-oesophageal echocardiography is the technique of choice with which to detect left atrial masses' 3-41. We report a case of left atrial thrombus presenting with the echocardiographic and clinical features of an atrial myxoma, which was successfully treated with anticoagulant therapy. In July 1992, a 82-year-old male patient was hospitalized as a result of a syncopal episode which occurred while he knelt to tie his shoes. He referred to a history of chronic obstructive pulmonary disease and systemic arterial hypertension. His physical examination showed neither pathological cardiac murmurs nor carotid or vertebral bruits; neurologi-cal examination was normal; blood pressure was 160/100 mmHg; ECG showed atrial fibrillation with a normal ventricular rate (78 beats. min ~ ') and signs of left ventricular hypertro-phy; arterial gases were normal as was haematocrit, red blood cell count, serum creatinine, glucose level and urinalysis. Transthoracic echocardi-ography showed a mildly hypertro-phied left ventricle with a normal systolic function and an enlarged (5 cm) left atrium; cardiac valves were normal. A rounded, mobile, and echo-genic mass attached to the atrial sep-tum was imaged in the left atrium (Fig. 1, upper panel). To better define the anatomical characteristics of the mass and its relationship with the cardiac structures, transoesophageal echocardiography was performed. A large (4x4 cm), rounded and homogeneous mass was detected in the left atrium attached to the interatrial sep-tum via a stalk at the level of the fossa ovalis. The stalk allowed the mass to move slightly within the left atrium but not to prolapse into the left ven-tricle in diastole. The diagnosis of left atrial myxoma was made and surgery was advised. However, the patient refused to undergo an operation and was discharged on digoxin, captopril and warfarin therapy. He remained asymptomatic, and 2 months later transthoracic echocardiography was repeated. Surprisingly, the left atrial Figure 1 Two-dimensional trans-thoracic echocardiography. Apical five-chamber view at the time of hospitalization (upper panel) and after 2 months of warfarin therapy (lower panel). The left atrial mass detected at first evaluation was no longer evident after therapy. mass was no longer evident (Fig. 1, lower panel). Indeed, the persistence of the mass was shown by trans-oesophageal echocardiography but its size was reduced to a half. The patient died …