Aortic valve stenosis

Aortic valve stenosis – or aortic stenosis (AS) – is a condition where the aortic valve in the heart is unable to completely open, which restricts blood flow from the left ventricle to the aorta. This restriction leads to the development of abnormally high pressure in the left ventricle as the ventricle must “push harder” to force blood through the narrowed valve.

The more severe the stenosis, the harder the left ventricle must work to pump blood to the body. If the problem is not treated, this overwork causes the left ventricle wall to thicken or “hypertrophy”. Eventually the muscle may become damaged, resulting in left-sided heart failure and abnormal heart rhythms. Abnormal aortic valves may also fail to close properly, allowing blood to “leak” or flow back into the left ventricle; this is called aortic incompetence or regurgitation. AS also increases the risk of developing an infection in the lining of the heart. This is known as infective endocarditis (IE).

Diagram showing valves of normal heart compared to thickened and narrowed valve of heart with aortic stenosis.

Signs and symptoms

Mild AS may cause no symptoms, but problems can occur when aortic stenosis is moderate to severe.

The main signs and symptoms of aortic stenosis include:

  • Irregular heart sound (heart murmur)
  • Shortness of breath during exercise
  • Decrease in exercise tolerance (fatigue)

How is aortic valve stenosis diagnosed?

Tests that help diagnose AS include:

  • Electrocardiogram (ECG) – this will measure the electrical activity of the heart.
  • Echocardiogram (Echo) – a test that uses sound waves to produce a picture of the heart.
  • Cardiac catheterisation – this is an X-ray procedure performed under a general anaesthetic. A doctor will insert a thin, flexible tube into a blood vessel in the groin. The tube is fed up to the heart where the doctor can measure pressures and oxygen levels and visualise heart structures using X-ray equipment.

These tests are usually performed because a doctor has heard a heart murmur (turbulent blood flow) when examining a child with a stethoscope.


Treatment for AS depends on a child’s age, overall health, and degree of stenosis. Mild aortic stenosis may not require treatment but more moderate to severe cases usually require treatment. This can be through cardiac catheterisation (a procedure to place a small tube into a vessel in the heart) or surgery to repair or replace the obstructed valve.

Balloon valvuloplasty

During cardiac catheterisation, a flexible tube with an inflatable balloon at the tip is inserted into the blood vessel in the groin. When the tip of the catheter is through the valve, the balloon is inflated to stretch open the valve.

This can produce effective long-term relief of the obstruction. Some patients who are unsuitable for this type of procedure, or in whom it is unsuccessful, may then require surgery to correct the problem. Children having this procedure will usually have a one- or two-night stay in hospital.

Aortic valve surgery

There are a number of surgical options including:

  • Valvotomy is a procedure where the thickened and fused leaflets are surgically opened allowing the valve to function more normally.
  • Aortic valve replacement is when the valve is replaced with either a human, animal, or artificial valve.
  • Aortic homograft is when the valve and some of the aorta are replaced using a valve from a human donor.
  • Pulmonary homograft (Ross Procedure) involves taking a section of your child’s own pulmonary artery including the intact pulmonary valve and using it to replace a section of the aorta and the aortic valve. The child’s pulmonary artery and valve is then replaced by using a valve and tissue from a human/cow/pig donor.
  • Mechanical valves can also be placed in children. Blood thinning medications will be required long-term with this option.

When to seek help

  • In case of emergency immediately call Triple Zero (000).
  • If it’s not an emergency but you have any concerns, contact your GP or 13 HEALTH (13 43 25 84).
  • If you are in the care of a cardiologist, and you have any non-urgent concerns or questions about your child, contact your cardiac care coordinator.

Developed by the Cardiology Department, Queensland Children’s Hospital. We acknowledge the input of consumers and carers.

Resource ID: FS370. Reviewed: June 2023.

Disclaimer: This information has been produced by healthcare professionals as a guideline only and is intended to support, not replace, discussion with your child’s doctor or healthcare professionals. Information is updated regularly, so please check you are referring to the most recent version. Seek medical advice, as appropriate, for concerns regarding your child’s health.

Last updated: October 2023