OverviewAn 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.
Update Date 1/19/2016
Updated by: Larry A. Weinrauch MD, Assistant Professor of Medicine, Harvard Medical School, Cardiovascular Disease and Clinical Outcomes Research, Watertown, MA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.