Pulmonary atresia

Pulmonary atresia is a congenital malformation of the pulmonary valve in which the valve orifice fails to develop. The valve is completely closed thereby obstructing the outflow of blood from the heart to the lungs. The pulmonary valve is located on the right side of the heart between the right ventricle and pulmonary artery. In a normal functioning heart, the opening to the pulmonary valve has three flaps that open and close.

In congenital heart defects such as pulmonary atresia, structural abnormalities can include the valves of the heart, and the walls and arteries/veins near the heart muscle. Consequently, blood flow due to the aforementioned structural abnormalities is affected, either by blocking or altering the flow of blood through the human cardiac muscle.