An atrial septal defect (ASD) is a congenital heart defect, a problem with the heart’s structure that is present at birth. Put most simply, an ASD is an abnormal hole in the wall that divides the atria—the two upper chambers of the heart. Some ASDs are small and close on their own. Others are larger and, if left untreated, may cause damage to the heart over time.
While ASDs are often identified in the first year of life, they also have been diagnosed later in childhood and, occasionally, even in adulthood. Whenever the condition is discovered, ASDs need to be closely monitored and appropriately treated.
Atrial septal defects in childhood tend to not cause significant symptoms and are picked up most commonly at a murmur examination, or when an echocardiogram is done for another reason, says Yale Medicine pediatric cardiologist Dina Ferdman, MD. “The majority of these defects, when found in early infancy, resolve completely on their own. Small ASDs do not require any treatment and may be monitored every couple of years,” she says. “But those that do persist into early childhood—and remain large—can be closed with a procedure in the pediatric cardiac catheterization laboratory, avoiding the need for cardiac surgery.”