Pulmonary Stenosis

What is Pulmonary Stenosis?

(© Competence Network for Congenital Heart Defects)

Pulmonary means ‘of the lungs’. Stenosis means narrowing. Pulmonary stenosis is a narrowing of the pulmonary valve.

This narrowing means that the right ventricle has to work harder to pump blue (deoxygenated) blood through the pulmonary valve, into the pulmonary artery and finally to the lungs to pick up oxygen.


Your child’s pulmonary stenosis may have been seen on a scan during pregnancy. It can also be diagnosed after birth when the sound of blood moving through the narrow valve can be heard as a heart murmur.

Pulmonary stenosis can be the only heart condition a child has. However, it is also fairly common to find that a child with pulmonary stenosis also has other heart conditions.

When a heart condition is suspected the tests used can be:

  • Listening with a stethoscope for changes in the heart sounds;
  • An ultrasound scan (echo) to see how the blood moves through the heart;
  • An oxygen saturation monitor to see how much oxygen is getting into the blood
  • A chest x-ray to see the size and position of the heart;
  • An ECG (electrocardiogram) to check the electrical activity of the heart;
  • Checks on the chemical balance in the blood and urine; and
  • Measuring the pulse, blood pressure, temperature, and number of breaths a baby takes a minute.


The treatment for pulmonary stenosis depends on how narrow the valve is. If your child has other heart conditions, the kind of surgery needed will depend on how the heart can best be changed to cope with all the problems they have.

In many cases, pulmonary stenosis on its own will not cause a child to be unwell. If this is the case, then the child will have regular appointments with a cardiologist to check that their condition does not get any worse. 

If there is severe narrowing, then the right ventricle will have too much work to do. In such cases, doctors will try to make changes that will allow more blood to be pumped through the pulmonary valve with less effort from the right ventricle.

For most children the following procedures are low risk, but it can depend on how well your child is otherwise. The doctors will discuss risks with you in detail before asking you to consent to the operation.

Balloon dilation

A tube is inserted through a vein in the groin and up into the heart. Once it reaches the right spot, a balloon on the end of the tube is inflated causing the narrow pulmonary valve to stretch. This does not leave any scar a child will only need to spend one or two days in hospital.

Corrective surgery

In very severe cases, open heart surgery may be needed. This means the heart will need to be stopped and opened to repair it. A machine called a heart bypass machine will take over the job that the heart normally does.

The aim of the operation is to make the area around the pulmonary stenosis bigger. Sometimes the pulmonary valve will also need to be replaced. The replacement valve is usually a homograft (a valve taken from a donor person). These valves may need replacing after a few years.

The length of time in hospital after surgery will usually be about 5-7 days, of which one or two will be spent in the intensive care and high dependency unit. Of course, this depends on how well a child is before and after the surgery, and whether any complications arise.

How the child is affected

Most children are completely well, active, and gaining weight a few days after treatment. After surgery, your child will have a scar down the middle of the chest, and there may be small scars where drain tubes were used.  These fade very rapidly in most children but they will not go away altogether.  Smaller scars on the hands and neck usually fade away to nothing.

One problem that can happen after a procedure or later on is that the pulmonary valve begins to leak. If this happens, it may need further repair or replacement.

Author(s): Children’s Heart Federation
Last updated: 2012-04-12