A Case with Recurrent Free-Floating Ball Thrombi in Left Atrium

Abstract

BACKGROUND A free-floating ball thrombus in the left atrium is a rare clinical condition. However, the diagnosis of this condition has been facilitated by the advent and development of echocardiography and multi-detector row computed tomography (MDCT) and several cases have been reported. CASE REPORT We report a case of a 75-year-old woman who had recurrent giant spherical thrombi in the left atrium. She was diagnosed with chronic atrial fibrillation at 52 years of age. A pacemaker implantation was performed at 54 years of age because of a complete atrioventricular block; and mitral valve replacement was performed for severe mitral regurgitation at 62 years of age. She had a history of cerebral infarction and she was under treatment for chronic heart failure. Despite intensive anticoagulant therapy, she developed ball thrombi in the left atrium three times in six months. During hospitalization for acute myocardial infarction treated with percutaneous catheter intervention, transthoracic echocardiography and computed tomography (CT) revealed a free-floating giant spherical thrombus in the left atrium. She was treated with intensive anticoagulation therapy and the left atrial ball thrombus disappeared; however, two ball thrombi in the left atrium and left atrial appendage recurred after three months. Surgical removal of the thrombi and closure of the left atrial appendage were performed. Unfortunately, a ball thrombus in the left atrium recurred again after a further three months. CONCLUSIONS The present case highlights the difficulty of treating refractory thrombi in the left atrium.

Figure 1.

(A) Computed tomography (CT) scan of the heart showing free-floating thrombus with contrast (left panel, arrow). Because the ball thrombus was moving in the left atrium, it looked blurred by CT scan. The same thrombus detected by CT scan without contrast (right panel, arrow) showing its change of position in the left atrium. (B) Transthoracic echocardiography (TTE) showing that the ball thrombus (arrow) was moving freely.

Figure 2.

Computed tomography (CT) scan of the heart with contrast showing the ball thrombi generated in the left atrium and the left atrial appendage (arrow).

Figure 3.

The ball thrombus in the left atrium (A) at surgery, and the two thrombi (B) after removal.

Figure 4.

Computed tomography (CT) scan showing a recurrent smaller thrombus (arrow) arising from the posterior wall of the left atrium (A) and its subsequent expansion (B).