Coarctation of the aorta (COA) factsheet


Coarctation of the aorta (COA) is a condition where the aorta becomes narrowed or constricted. 

The aorta is the biggest blood vessel in the body. When it becomes too narrow, it becomes difficult for the left side of the heart to pump blood through to the rest of the body. 

COA is a congenital defect, which means it is a difference in your child’s heart that develops during pregnancy.

Untreated COA can cause: 

  • high blood pressure
  • the heart to grow larger than normal
  • coronary artery disease
  • kidney problems
  • dissection or rupture of the aorta – a life-threatening condition where the aorta tears apart.

Some children will have COA that does not cause any symptoms. Other children may need surgery to treat the condition.

 Signs and symptoms

Symptoms of COA can range from very mild, to severe.

Some children will not have any symptoms at all. The condition can sometimes be found during a check-up with your child's doctor.

Children with COA might have symptoms like:

  • high blood pressure that is not caused by anything else
  • a heart murmur - an abnormal sound that comes from the heart
  • a weak pulse or heartbeat in the groin area
  • cold legs and feet
  • difficulty breathing
  • difficulty feeding from the breast or bottle
  • heavy sweating
  • skin that is more pale than usual
  • headaches
  • chest pain
  • muscle weakness. 

See your local doctor if your child shows any signs or symptoms of COA.

Go to your nearest emergency department or call triple zero (000) for an ambulance if your child has abnormal chest pains or difficulty breathing.


Your child's doctor will take a medical history and check your child's symptoms. They will refer you to a heart specialist, or cardiologist, to test for and diagnose COA.

The cardiologist will listen to your child's heart and pulse and check their blood pressure. They will also order tests and scans like:

  • echocardiogram — a test that uses sound waves to create a picture of the heart and its circulation 
  • x-ray, MRI, and CT scans – to take detailed photos of the heart's structure.

COA is usually found early, but some children may not have symptoms until they are older.


Once COA is diagnosed, it needs to be treated quickly.

Severe cases of COA are usually found shortly after a baby is born and need immediate surgery to fix. 

Most children who have surgery to fix COA will recover well but will still need to see their cardiologist regularly throughout their lives.

Surgery to treat COA aims to:

  • make the narrow part of the aorta bigger
  • remove the narrow part and reconnect the ends of the aorta.

Balloon angioplasty

A balloon angioplasty or dilation is a procedure used to make the narrow part of the aorta wider. This procedure is done under general anaesthesia so your child will be asleep and not feel any pain. It is a closed-heart procedure, which means your child's chest wall will not be opened up.

In balloon angioplasty, a long, flexible tube or catheter with a tiny balloon on the end is inserted through a blood vessel in the leg or arm. The catheter travels through to the narrow part of the aorta. 

Once the catheter is in the right spot, the balloon is inflated. This opens up the aorta and lets the blood flow normally.


In some procedures, the surgeon will place a small tube-shaped wire cage where the aorta has been widened. This is called a stent. 

The stent is used to make sure the aorta does not become narrow again.


Recovery and follow-up care

Most COA symptoms should go away after surgery. Recovery may take some time and physical activity should be limited. Your child's treatment team will let you know when your child can return to their normal activities. 

Your child may need to continue taking medication for a period after the procedure. 

COA can come back in some children, so your child will need to have regular follow-up appointments with their cardiologist as they grow.

Last updated Monday 29th April 2024


This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2024