Atrial Septal Defect (ASD)

How does the ASD affect my child? Children with an ASD often have no symptoms. If the opening is small, it won’t cause symptoms because the heart and lungs don’t have to work harder. If the opening is large, the only abnormal finding may be a murmur (noise heard with a stethoscope) and other abnormal heart sounds. In children with a large ASD, the main risk is to the blood vessels in the lungs because more blood than normal is being pumped there. Over time, usually many years, this may cause permanent damage to the lung blood vessels.