Complications of congenital heart disease 

Children and adults with congenital heart disease are at an increased risk of developing further problems.

Developmental problems

Many children with congenital heart disease experience delays in their development. For example, they may take longer to start walking or talking. They may also have lifelong problems with physical co-ordination.

Some children with congenital heart disease also have learning difficulties. These are thought to be caused by a poor oxygen supply during early life, which affects the development of the brain.

Natural intelligence is usually unaffected, but some children often perform well below the academic level they would be expected to reach.

This is because of problems such as:

  • impaired memory
  • problems expressing themselves using language
  • problems understanding the language of others
  • low attention span and difficulty concentrating
  • poor planning abilities
  • poor impulse control  acting rashly without thinking about the possible consequences

These can lead to problems with social interaction and behaviour in later life.

Respiratory tract infections

The risk of developing respiratory tract infections (RTIs) is higher in people with congenital heart disease. RTIs are infections of the lungs and airways, such as pneumonia.

Symptoms of an RTI can include:

  • a cough, which can be severe and bring up phlegm and mucus
  • wheezing
  • rapid breathing
  • chest tightness

Treatment for an RTI depends on the cause. For example, infections caused by bacteria can be treated with antibiotics.


People with congenital heart disease also have an increased risk of developing endocarditis. This is an infection of the lining of the heart and valves, or both. If it's not treated, it can cause life-threatening heart damage.

Symptoms of endocarditis can include:

  • a high temperature (fever) of 38C (100.4F) or above
  • chills
  • loss of appetite
  • headache 
  • muscle and joint pain
  • night sweats
  • shortness of breath 
  • persistent cough

Endocarditis will need to be treated in hospital with antibiotic injections.

The condition usually develops when an infection in another part of the body, such as on the skin or the gums, spreads through the blood and into the heart.

As gum disease can potentially lead to endocarditis, it's very important to maintain excellent oral hygiene if you have congenital heart disease.

It's also usually recommended that you avoid having any cosmetic procedure that involves piercing the skin, such as tattoos or body piercings.

Pulmonary hypertension

Some types of congenital heart disease can cause the blood pressure inside the arteries that connect the heart and lungs to be much higher than it should be. This is known as pulmonary hypertension.

Symptoms of pulmonary hypertension can include:

  • shortness of breath
  • extreme tiredness 
  • dizziness
  • feeling faint
  • chest pain 
  • a rapid heartbeat

A range of medications can be used to treat pulmonary hypertension. Read more about treating pulmonary hypertension.

Heart rhythm problems

Children and adults with congenital heart disease are at risk of developing different types of heart rhythm problems. These may come from the top of the heart (atrial arrhythmia) or from the ventricular chambers, which are more concerning (ventricular arrhythmia).

At rest, a normal heart rate is between 60 and 100 beats a minute. The heart may either beat too slowly, which may require a pacemaker, or too fast, which may require medication or, rarely in a child, an implantable cardioverter defibrillator to deliver an electric shock to the heart to stop the rhythm problem.

There are two particular fast rhythms that come from the top of the heart and become more common with age. These are atrial fibrillation and atrial flutter.

Sudden cardiac death

There's a small but significant risk of sudden cardiac death in people with a history of congenital heart disease. It's estimated that 1 in every 1,000 adults with congenital heart disease die suddenly in this way every year.

Identifying people at risk of sudden cardiac death is difficult, but those with higher risk ventricular arrhythmias should be fitted with an implantable cardioverter defibrillator.

However, many people have a sudden cardiac death without a rhythm problem being identified, so it's a concern for most people with congenital heart disease.

Heart failure

Heart failure is where the heart can't pump enough blood around the body to meet the body's needs. It can occur shortly after a baby with a severe congenital heart defect is born, or as a later complication, of any treated or untreated type of congenital heart disease.

Symptoms of heart failure can include:

  • breathlessness when you're active or sometimes resting
  • extreme tiredness and weakness
  • swelling in the abdomen (tummy), legs, ankles and feet

Treatments for heart failure can include medication and the use of an implanted device such as a pacemaker.

Many types of surgery for congenital heart disease are referred to as palliative, because they're not able to perfectly recreate a normal physiological circulation. This is particularly true for people with tricuspid atresia and single ventricles. Although palliative surgery may work well for many decades, there are elements of this unusual circulation that can fail.

In this case, medication and alternative surgery or interventional procedures may be necessary. Ultimately, if there are severe symptoms of heart failure that don't improve with treatment, a heart transplant may need to be considered. However, in the UK, relatively few heart transplants are carried out each year, because of the shortage of donated hearts.

Read more about treating heart failure.

Blood clots

Having a history of congenital heart disease can also increase the risk of a blood clot forming inside the heart and travelling up to the lungs or brain.

This can lead to a pulmonary embolism (where the blood supply to the lungs is blocked) or a stroke (where the blood supply to the brain is blocked).

Medications can be used to prevent, dissolve or remove blood clots.

Congenital heart disease and pregnancy

Many women with congenital heart disease can have a healthy pregnancy, but pregnancy puts an extra strain on the heart and can cause problems.

If you have congenital heart disease and you're considering having a baby, you should discuss it with your heart specialist (cardiologist).

If you have congenital heart disease and you become pregnant, you must seek help from healthcare professionals with experience in treating pregnant women with a history of the condition.

Read more about congenital heart disease in pregnancy.

Page last reviewed: 05/06/2015

Next review due: 05/06/2017