Congenital heart disease

Congenital heart disease is the name for heart problems people are born with.

Congenital heart defects usually happen by chance, during the complex development of the heart. There are many different types of congenital heart problems, each of which require different treatment approaches.

Key points

  1. Congenital heart disease affects about 1 in a 100 babies, although some conditions are not diagnosed until adulthood.
  2. If you have congenital heart disease, even if you had surgery as a child, you will need to have a lifetime of follow-up care.
  3. Treatment of congenital heart disease has improved dramatically over the last 30 years and there are now many treatment options available.
  4. Ensure your health practitioner has experience managing congenital heart conditions and work closely with them in developing the best treatment plan for your situation. 


Congenital heart defects are usually a chance occurrence due to a slight fault in the complex development of the heart. It is rare for a heart defect to be inherited, that is, to occur because of faulty genes from either parent. Some known causes of congenital heart disease include:

  • Rubella (German measles) virus can damage the developing heart. A mother who comes in contact with rubella in the first three months of a pregnancy should consult her doctor.
  • Some medication may cause heart defects. Do not take medication in early pregnancy except on a doctor's recommendation.

Things such as getting a bad fright, having an accident or a threatened miscarriage do NOT cause congenital heart defects. Babies are well-protected in the womb from most outside influences.

How the heart works

The heart is a pump and its main function is to pump blood around the body. It is separated into left and right sides by a muscular partition (septum). The left side of the heart pumps red blood containing oxygen and other fuels through the main artery, or aorta, to the arteries of all parts of the body.

Tissues in the body, such as muscle, brain and kidneys, use some of the oxygen in the blood, leaving it with a blue tinge. The 'blue' (deoxygenated) blood returns in the veins to the right side of the heart which pumps it through the pulmonary arteries to the lungs. Here, the blood receives oxygen again, restoring its red colour, and returns to the heart ready to be pumped once more through the body.

Valves are important in directing flow.

  • Each side of the heart has a receiving chamber (the atrium) and a pumping chamber (the ventricle).
  • As with any pump, valves are necessary to keep flow in the proper direction and each side of the heart has two valves, one at either end of the ventricle.
  • The right-sided valves are called the tricuspid and pulmonary valves, and the left-sided valves are called the mitral and aortic valves.

Types of heart defects

Some of the main heart defects are:


Stenosis is a significant narrowing of a heart valve. It means the heart has to work a lot harder to pump blood through the narrowed valve.


Abnormal narrowing may also occur in the aorta. Coarctation is corrected surgically.


Also called incompetence: regurgitation is when one or more valves do not close properly, allowing blood to flow back into the heart chamber, which puts extra load on the heart. Surgery may be needed if the valve defect is severe.

Holes in the heart 

Holes within the heart may occur in the muscular partition between the atria (an atrial septal defect) or the partition between the ventricles (a ventricular septal defect). These holes allow an abnormally large amount of blood to flow into the right side of the heart and through the lungs.

If the hole is very large, surgery may be required in infancy. Children with large heart defects will easily get breathless, have a tendency to get chest infections and will not put on weight easily. Those with smaller holes will often make satisfactory progress and surgery can be postponed. In some cases of ventricular septal defect, the hole may become smaller as the child grows older so an operation may be avoided altogether.

Patent ductus arteriosus 

Before birth, a duct or channel between the aorta and pulmonary artery allows blood to bypass the lungs, which have no function while the baby is still in the womb. This channel normally closes at birth but if it doesn't, the effect is similar to that caused by a hole in the heart. It is relatively easy to correct.

Blue babies 

There are a number of more complicated defects in which some 'blue' and red blood mixes. Blueness (cyanosis) may not be present all the time but any baby who becomes blue and breathless needs to have his or her heart checked urgently. Heart disease that causes cyanosis cannot get better on its own, but in most cases the defect can be detected by ultrasound and corrected surgically.


In most cases, a medical examination with an x-ray of the heart, an electrocardiogram (ECG) and an echocardiogram will be enough to decide if a heart defect requires treatment. Sometimes cardiac catheterisation is necessary. In this test, carried out under anaesthetic, special tubes are passed through an artery and/or vein to take recordings and x-rays of the heart. This will provide the cardiologist and heart surgeon with detailed knowledge of the structure of the heart so they can decide on the best form of treatment.


Treatment for congenital heart disease has improved dramatically over recent years. It includes all the self-help measures listed below, as well as various surgical operations and medications to keep your heart working as well as possible. Because there is such a big variety in type and severity of congenital heart problems, your doctor will need to recommend the best treatment option for your particular situation.

The following websites contain some general information on treatment options, but you need to check with your cardiologist what is right for you:

Surgical procedures John Hopkins University
Medications commonly used Heart Foundation, NZ
How is congenital heart disease treated? Heart Foundation, NZ

Self care

Congenital heart disease is a heart problem you are born with, and for many, one you will have for the rest of your life. While you may not face ongoing heart problems, you are at increased risk of developing heart complications. Therefore, if you have congenital heart disease, even if you had surgery as a child, you will need to have follow-up care for the rest of your life. This may be as simple as an annual check-up with your GP, or may require more extensive testing with a cardiologist. The most important thing is that you understand your condition and the steps you need to take to keep yourself healthy. 

Dental care & infective endocartitis

Congenital heart disease can increase your risk of developing infective endocarditis – an infection of the tissue that lines the heart (the endocardium). Infective endocarditis can be caused by bacteria entering the bloodstream. Poor dental hygiene and dental surgery both increase the risk of this happening. To help prevent infective endocarditis:

  • Don't let any dental problems such as a dental abscess or gum disease go untreated. These dental conditions increase the chance of bacteria getting into the bloodstream.
  • Inform your dentist about your heart condition before you get any dental work done. You may need to take a preventative course of antibiotics.

More information on infective endocarditis and advice on preventing endocarditis from dental work from the NZ Heart Foundation.

What else can I do?

Healthy eating, regular exercise (check with your doctor first), being a non-smoker, taking your medications correctly, having a positive attitude and seeing your healthcare team regularly, are all very important steps you have control over for keeping well.

Attend a self-management programme Health Navigator, NZ
Living with heart disease Heart Foundation, NZ

Learn more

The following websites provide a range of resources and information on congenital heart disease. Most are American, Canadian or from the UK as there is less information available from NZ sources.

Congenital Heart Disease John Hopkins Childrens Centre
Congenital Heart Disease in children Heart Kids New Zealand
Canadian Adult Congenital Heart Network Canadian Adult Congenital Heart Network

Reviewed By: Health Navigator