An unusual thrombotic complication during percutaneous closure of atrial septal defect.

A case is described where intracardiac thrombus was observed at the junction of the superior vena cava and the right atrium during attempted closure of an atrial septal defect (ASD) using a device similar in design to the Amplatzer septal occluder (Heart R atrial septal occluder). Thrombosis was likely related to the multiple attempts required when deploying the device and the attendant prolonged procedural time. The patient underwent subsequent urgent surgical closure of the ASD.