- Pulmonary atresia
- Slide show: Common types of congenital heart defects
In pulmonary atresia, the valve that lets blood flow from the heart to the lungs isn't formed properly. Instead of having leaflets of tissue that open and close, the valve is a solid sheet of tissue in pulmonary atresia, preventing the blood from passing through the valve to the lungs. Babies born with pulmonary atresia also often have a small (hypoplastic) right ventricle.