Matthew 25:40

"And the King will answer and say to them, ‘Assuredly, I say to you, inasmuch as you did it to one of the least of these My brethren, you did it to Me.’ "

Saturday, December 6, 2008

Hypoplastic Left Heart Syndrome (HLHS)

What is HLHS?

Hypoplastic means ‘not developed’. Left Heart – the structures on the left side of the heart.Syndrome – a number of anomalies together. So HLHS means that the left side of the heart has not developed properly – the left ventricle, which should pump red (oxygenated) blood to the body, is very small, and there is a complete blockage between it and the aorta. The aorta, which should carry red blood to the body, is much too small.


Your baby may have been diagnosed as having a heart condition before birth. HLHS can be seen on a scan of the foetal heart from about 16 weeks. HLHS can develop if there is a blocked or narrow valve, when the left side of the heart does not grow as it should during the later stages of pregnancy.

After birth, your baby can survive before the foetal circulation system has closed down. This is because red blood will still be crossing from the left atrium to the right. From there it will be pumped, with blue blood, into the pulmonary artery. While the ductus arteriosus is still open, blood will flow through it into the aorta, and thus round the body.

Often your baby will only be diagnosed because, as the foetal circulation closes down, less and less oxygen reached organs and he or she became extremely ill.

When a heart problem is detected the tests used can be:

  1. pulse, blood pressure, temperature, and number of breaths a baby takes a minute

  2. listening with a stethoscope for changes in the heart sounds

  3. an oxygen saturation monitor to see how much oxygen is getting into the blood

  4. a chest x-ray to see the size and position of the heart

  5. an ECG (electrocardiogram) to check the electrical activity

  6. an ultrasound scan (echocardiogram) to see how the blood moves through the heart

  7. checks for chemical balance in blood and urine

  8. a catheter or Magnetic Resonance Imaging test may be needed.


This is a very difficult problem to treat: The treatment for HLHS is palliative. 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 Norwood operation (palliated). The aim of the treatment is to use the pumping power of the right ventricle to get blood to the body and the lungs. This means that your child will have one working ventricle.

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.

If you have had the condition diagnosed during pregnancy, there is time to think about the treatment options, but time is often very short to take decisions on behalf of a newborn.

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. 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 (Fontan operation).

Other forms of treatment:

Transplantation: This is very rarely available in the UK. It 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. Transplants into very young babies are often more successful than older children or adults, but a majority of babies die waiting for a heart to become available.Other forms of treatment are being used in some Paediatric Cardiology Units and these are developing all the time.