Neonatal Thrombus in the Left Atrial Appendage That Manifested Mobility with Improvement in Left Ventricular Function

Abstract

Thrombus formation within the left atrial appendage is extremely rare in neonates. For intracardiac thrombus, anticoagulation therapy is the most common option of treatment. In high-risk cases of systemic embolism, however, surgical resection should be considered. We experienced a neonatal case with a left atrial appendage thrombus related to transient left ventricular dysfunction without congenital heart malformation; the definitive etiology of cardiac dysfunction remained unknown. Daily echocardiography revealed that mobility of the thrombus became prominent as the left ventricular systolic function improved. Surgical thrombectomy was performed due to an imminent concern of its embolic risk. We herein report details of the highly suggestive clinical course in our patient.