Normally, blood passes through it to go into the aorta, subaortic stenosis limits the flow of blood out of the left ventricle. Treatment depends on the cause and the severity of the narrowing, and may include drugs or surgery. Usually there are no symptoms at birth, but symptoms can develop as early as the first week after birth. Although a baby may develop congestive heart failure or high blood pressure that requires early surgery, surgery usually can be delayed. However, a child with a severe coarctation should have surgery in early childhood to prevent future problems such as developing high blood pressure as an adult.
Treatment depends on how well the valve functions.
Some congenital heart defects allow blood to flow between the right and left chambers of the heart. Many children with ASD have few, if any, symptoms. Closing the atrial defect by open heart surgery in childhood can often prevent serious problems later in life. It is usually associated with an atrial septal defect. Because the heart becomes over-worked, it may enlarge.