Hypoplastic Left Heart Syndrome

HLHS is a very difficult problem to treat. The treatment for this condition is palliative. This means your child’s heart cannot be corrected, that is, made to work like a normal heart. But in some cases it can be improved with a procedure called the Norwood operation.

Norwood Procedure

This is a high risk procedure. It is a series of three surgical operations which would eventually allow the right side of your child’s heart to take over the work of the left side.
The aim of the three operations is for the right ventricle to pump red blood to the body, while the blue blood is allowed to flow directly to the lungs.

Stage One

In the first few days of life, the wall between the left and right atrium is removed so that red blood coming back from the lungs will pass into the right atrium, and from there to the right ventricle. The pulmonary artery is attached to the aorta. A shunt (passage) is created between the aorta and the pulmonary artery branches to the lungs. Mixed red and blue blood will now be pumped through the pulmonary artery to the aorta, to both lungs and to the body.

Stage Two

Between the ages of four to nine months the blood flow to the lungs is increased. The SVC (superior vena cava), which carries blue blood from the top of the body to the right atrium, is joined directly to the pulmonary arteries. The shunt between the aorta and the branch arteries created at stage one is closed.

Stage Three

The IVC (Inferior vena cava), which carries blue blood from the lower part of the body to the right atrium, is joined directly to the pulmonary arteries. This procedure is also known as the Fontan operation.

There is a risk to your child in all the procedures, but how great that risk is depends on the shape of the individual heart, and how well your child is otherwise. The doctors will discuss risks with you in detail before asking you to consent to any of the operations.

Other forms of treatment


Some doctors will recommend a heart transplant to treat HLHS. This will involve trying to keep your baby’s foetal circulation open, using medicines or a stent in the ductus arteriosus, while waiting for a heart to become available. At present, however, transplantation is rarely available in the UK as there are very few baby size hearts available.

Learn more about Hypoplastic Left Heart Syndrome

Author(s): Children’s Heart Federation
Last updated: 2009-12-09