Cardiac catheterisation factsheet


Cardiac catheterisation is a test used to obtain detailed information about the heart. Often this information cannot be gathered by other tests, such as echocardiography. 

Cardiac catheterisation can be used to treat some heart abnormalities such as blocked valves or arteries. This is called an interventional catheterisation.

The test or treatment is carried out in a sterile area, like an operating theatre. Often it is performed under general anaesthetic for safety reasons.

The catheter is a fine, hollow, flexible tube, which is usually introduced into the artery and/or vein on either or both sides of the groin. Sometimes other entry sites are used, such as the arm or neck veins. The catheters are introduced through one to two millimetre needle holes.

The test itself is safe. However, procedures involving entry into the body carry a risk of serious complications, which can vary depending on the specific requirements of the procedure. It's important to discuss potential complications with the cardiologist or cardiology fellow who will perform the procedure. The benefits of the procedure in diagnosing and treating your child's heart condition far exceed the associated risks.

 Before the procedure

Your child will be admitted to hospital the day before the procedure, or sometimes on the morning of the procedure. 

On admission to the hospital ward they will be examined by the resident doctor, the cardiology fellow (who will perform part of the procedure with the cardiologist), the anaesthetist, and a nurse. 

A blood test may be necessary if the procedure is done to stretch a heart valve, dilate blood vessels, close a hole, or if the procedure is being done on a small baby.

Your child will not be allowed to eat or drink anything for about six hours before the procedure. Sometimes a sedative is ordered by the anaesthetist and given about half an hour before the procedure 

The test usually takes one and a half to two hours. 

 During the procedure

The catheter is guided by the doctor carrying out the procedure, using sophisticated x-ray equipment. The end of the catheter is passed into the heart chambers and main arteries and veins. Blood pressure measurements and oxygen levels are measured at these points to help determine heart function.

A special fluid, containing iodine, is injected via the catheter to outline the heart chambers and blood vessels more clearly. This is called an angiogram and is recorded. This information can be critical when deciding how best to treat abnormalities of the heart.

In some cases, special catheters with sausage shaped balloons attached, can be used to enlarge narrowings. Sometimes various plugs or coils are introduced through the catheters to close off abnormal connections between blood vessels or holes in the partition between the heart chambers. Most abnormalities, however, will still need surgery to be repaired.

 After the procedure

After the procedure and until discharge, the nurses will carry out regular monitoring of your child's temperature, blood pressure, respiratory rate, heart rate, the groin wound and their foot pulses.

Children often feel sleepy or a bit restless for a few hours after catheterisation. Some older children also experience vomiting. Small sips of water are given initially and increased as tolerated and a normal diet is resumed later that day. 

The groin wound is usually covered with steri-strips, which should be removed after one day. Sometimes there are a few stitches that should be taken out after three to five days by your local doctor. 

Your child should be able to go back to school after two days, but should not participate in any strenuous activities for two weeks. 


On discharge from the hospital you should be given information of how to look after your child at home after cardiac catheterisation, and what to do if there are any problems.

If all observations are satisfactory and fluids and diet are tolerated, children are often discharged home in the afternoon after the procedure. 

After interventional catheterisations, the child is often kept in hospital until the next day.


If your child is unwell after the procedure (2-4 weeks)

In the two to four weeks after the procedure, if your child is unwell, especially with fever, there is a small possibility this is related to the catheterisation. 

Unless there is a very clear explanation for the illness such as an obvious runny nose, it may be better to avoid antibiotics. After seeing your local doctor, contact your cardiologist for advice. 

Usually it will be just a childhood illness that can be managed by your family doctor, so don't panic.


Your cardiologist will talk to you after the procedure and briefly explain how the procedure went. The detailed examination of the information will then be made by the cardiologist in the days or weeks after the procedure. 

Sometimes this information also needs to be discussed with other members of the team, such as the other cardiologists or the surgeons. An arrangement for further contact or follow-up is made prior to leaving hospital.

Last updated Tuesday 9th July 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

This factsheet was produced with support from John Hunter Children's Hospital.