Congenital heart disease - Complications of congenital heart disease

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

Problems with development

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

Recent research has found that children who have had surgery for transposition of the great arteries have significant problems understanding a concept known as theory of mind (TOM).

TOM is the ability to understand other people's mental state and recognise that they may differ from your own. In other words, to recognise that everyone has their own set of desires, intentions, beliefs, emotions, perspective, likes and dislikes. In simple terms, TOM is the ability to see the world through another person's eyes.

An inability to recognise other people's mental states 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.

Endocarditis

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 damage to the heart.

Symptoms of endocarditis can include:

• a high temperature (fever) of 38ºC (100.4ºF) 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 injections of antibiotics.

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 into the heart.

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

It is also usually recommended not to have 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

It's relatively common for adults with a history of some types of congenital heart disease to develop an abnormal heartbeat. This is often a type of heart rhythm problem called atrial fibrillation or flutter.

With both of these heart rhythm problems, the heart may beat at more than 140 beats a minute. At rest, a normal heart rate is between 60 and 100 beats a minute.

Several treatment options are available for atrial fibrillation, including medications, surgery and an implanted device called a pacemaker.

Read more about treating atrial fibrillation.

Heart failure

Heart failure is where the heart cannot 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 when a previously mild and untreated type of congenital heart disease gets worse in later life.

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.

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
• stroke – where the blood supply to the brain is blocked

Medications are often used to prevent, dissolve or remove blood clots.

Sudden cardiac death

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

Identifying people at risk of sudden death is difficult. Some heart rhythm problems are known to have a high risk of this event. In these cases, a device called an implantable cardioverter defibrillator will be inserted. This is similar to a pacemaker and can deliver a pulse of electricity when required, which should stop your heart going into spasm. 

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