This procedure is done by placing a device such as Amplatzer "umbrella", CardioSEAL similar to percutaneous transcatheter therapy. A catheter is inserted in the vessels and threaded to the heart and inserted into the ASD closing the defect. Other closure device that have been used is the GORE HELEX Septal Occluder. After the device has been inserted and covers the defect, over time tissue will grow over the implant device to make it become part of the heart. Anticoagulant medication will be given to the patient for the first six months following the surgery: aspirin, clopidogrel or warfarin (Coumadin).