Ball thrombus in the right atrium after patch closure of atrial septal defect

An 18 year-old woman who underwent secundum atrial septal defect (ASD) closure with a dacron patch 10 months prior returned for follow-up examinations. She received no anticoagulation therapy and remained asymptomatic after surgery. The patient was in normal sinus rhythm and there was no abnormality in physical examination or coagulation testing. Transthoracic echocardiograms (TTE) showed a globular, moderate echoic, homogenous mass (2 cm 2 cm) attached to the anterolateral wall of the right atrium by a narrow stalk, moving back and forth during the cardiac cycle without changing shape or protruding into the right ventricle (Fig. 1A, Video 1). Delayed gadolinium-enhanced