What is pulmonary stenosis?

Pulmonary Stenosis

What is pulmonary stenosis?

Pulmonary stenosis is relatively common and accounts for about 10% of heart defects diagnosed during childhood. It can occur in children with otherwise normal hearts or along with other congenital heart defects such as atrial septal defect or Tetralogy of Fallot. It occurs more frequently in children with Noonan syndrome and Williams syndrome which are both rare genetic conditions.

The heart is a four-chambered pump with four heart valves. The valves are made of thin flaps of tissue that open to allow the blood to flow forward and close to prevent the blood from flowing backwards. The pulmonary valve (1) is located on the heart's right side. Blue blood that comes from the body is pumped from the right lower chamber called the right ventricle (2) to the pulmonary artery (3) and then circulates to the lungs.
When a child has pulmonary stenosis, the area where blood exits the heart's lower right chamber is too narrow. Usually, the pulmonary valve itself is affected which is called valvar pulmonary stenosis. This problem is often caused by fusion of the valve leaflets. Subvalvar stenosis is the term used when the narrowed area is below the valve. Supravalvar stenosis is the term used when the narrowed area is above the valve.