Why is an atrial septal defect a concern?
This heart defect can cause lung problems if not repaired. When blood passes through the ASD from the left atrium to the right atrium, a larger volume of blood than normal must be handled by the right side of the heart. Extra blood then passes through the pulmonary artery into the lungs, causing higher pressure than normal in the blood vessels in the lungs. An opening in the atrial septum allows blood to pass through from the left atrium to the right atrium. Extra blood causes higher pressure in the blood vessels in the lungs. The larger the volume of blood that goes to the lungs, the higher the pressure. The lungs are able to cope with this extra pressure for a while, depending on how high the pressure is. After a while, however, the blood vessels in the lungs become diseased by the extra pressure. As the right atrium works harder to pump a larger volume of blood, it enlarges. With this enlargement comes an increased risk of atrial tachyarrhythmias — abnormally rapid atrial heart rhy
