Hypoplastic left heart syndrome is a type of congenital heart defect in which the left side of the heart develops abnormally. HLHS prevents the heart from being able to pump oxygenated blood to the body. Complex heart conditions like HLHS require a lifetime of highly specialized, coordinated care that usually starts before birth. We know that you want the very best care for your child -- so do we. Duke’s pediatric heart doctors, surgeons, and other specialists are renowned for their expertise and breakthrough techniques that add up to high-quality, compassionate care for your little one.