Atrial Septal Defect (ASD)
An atrial septal defect (ASD) is an opening in the atrial septum. The atrial septum is the dividing wall between the two upper chambers of the heart (right and left atria). Septal defect can be a congenital (present at birth) heart defect or it can result from the failure of normal postnatal closure of a hole that is present in the heart of every fetus.
Normally, oxygen-poor (blue) blood returns to the right atrium from the body, travels to the right ventricle, then is pumped into the lungs where it receives oxygen. Oxygen-rich (red) blood returns to the left atrium from the lungs, passes into the left ventricle and then is pumped out to the body through the aorta.
An ASD allows oxygen-rich (red) blood to pass from the left atrium, through the opening in the septum, and then mix with oxygen-poor (blue) blood in the right atrium. Atrial septal defects occur in a small percentage of children born with congenital heart disease. For unknown reasons, girls have atrial septal defects twice as often as boys.
Many children have no symptoms and seem healthy. Some children, however, may experience fatigue, rapid breathing, shortness of breath, poor growth or frequent respiratory infections. Tests that may help diagnose ASD include a chest X-ray, electrocardiogram (ECG), echocardiogram (echo) or cardiac catheterization.
Treatment of ASD may include medical management, surgical repair, or even device closure. The majority of children who have had an ASD repair will live healthy lives. With early diagnosis and repair of an ASD, the outcome is generally excellent, and minimal follow-up is necessary.Previous Page Last Review Date: January 4, 2018