Atrial septal defect:

An atrial septal defect is a congenital heart defect where the wall between the right and left atria does not close properly, leaving a hole between the two atria.
- Reviewed last on: 5/12/2008
- Larry A. Weinrauch, MD, Assistant Professor of Medicine, Harvard Medical School, and Private practice specializing in Cardiovascular Disease, Watertown, MA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.