Hypoplastic left heart syndrome is a congenital heart defect where the left side of the heart is underdeveloped. For the first 10 to 11 days after birth, the patent ductus arteriosus, this closes soon after birth. Once closed, the right side of the heart is responsible for doing the work of both sides of the heart which can lead to heart failure and death if the heart is not surgically altered.

There is no known cure, aside from a heart transplant, for Hypoplastic left heart syndrome. There is, however, treatment that can help the infant live a long, productive life. The treatment was established in then 1980s, so survivors are just reaching their 30s. There have been no long-term studies completed to determine the life span of a patient with Hypoplastic left heart syndrome.

Even with treatment, a heart transplant will most likely be needed at some point in the child’s or adult’s life.