Congenital heart disease refers to a range of possible heart defects.

Aortic valve stenosis

Aortic valve stenosis is a serious type of congenital heart defect.

In aortic valve stenosis, the aortic valve that controls the flow of blood out of the main pumping chamber of the heart (the left ventricle) to the body's main artery (the aorta) is narrowed. This affects the flow of oxygen-rich blood away from the heart, towards the rest of the body, and may result in the left ventricle muscle thickening because the pump has to work harder.

Coarctation of the aorta

Coarctation of the aorta (CoA) is where the main artery (the aorta) has a narrowing, which means that less blood can flow through it.

CoA can occur by itself or in combination with other types of heart defects – such as a ventricular septal defect or a type of defect known as a patent ductus arteriosus.

The narrowing can be severe and will often require treatment shortly after birth.

Ebstein's anomaly

Ebstein's anomaly is a rare form of congenital heart disease, where the valve on the right side of the heart (the tricuspid valve), which separates the right atrium and right ventricle, doesn't develop properly. This means blood can flow the wrong way within the heart, and the right ventricle may be smaller and less effective than normal.

Ebstein's anomaly can occur on its own, but it often occurs with an atrial septal defect.

Patent ductus arteriosus

As a baby develops in the womb, a blood vessel called the ductus arteriosus connects the pulmonary artery directly to the aorta. The ductus arteriosus diverts blood away from the lung (which isn't working normally before birth) to the aorta.

A patent ductus arteriosus is where this connection doesn't close after birth as it's supposed to. This means that extra blood is pumped into the lungs, forcing the heart and lungs to work harder.

Pulmonary valve stenosis

Pulmonary valve stenosis is a defect where the pulmonary valve, which controls the flow of blood out of the right heart pumping chamber (the right ventricle) to the lungs, is narrower than normal. This means the right heart pump has to work harder to push blood through the narrowed valve to get to the lungs.

Septal defects

A septal defect is where there's an abnormality in the wall (septum) between the main chambers of the heart. The two main types of septal defect are outlined below.

Atrial septal defects

An atrial septal defect (ASD) is where there's a hole between the two collecting chambers of the heart (the left and right atria). When there's an ASD, extra blood flows through the defect into the right side of the heart, causing it to stretch and enlarge.

Ventricular septal defects

A ventricular septal defect (VSD) is a common form of congenital heart disease. It occurs when there's a hole between the 2 pumping chambers of the heart (the left and right ventricles).

This means that extra blood flows through the hole from the left to the right ventricle, due to the pressure difference between them. The extra blood goes to the lungs, causing high pressure in the lungs and a stretch on the left- sided pumping chamber.

Small holes often eventually close by themselves, but larger holes need to be closed using surgery.

Single ventricle defects

A single ventricle defect is where only one of the pumping chambers (ventricles) develops properly. Without treatment, these defects can be fatal within a few weeks of birth. Nowadays, however, complex heart operations can be carried out which improve longer-term survival but may leave a person with symptoms and a shortened life span.

Two of the more common single ventricle defects are described below.

Hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) is a rare type of congenital heart disease, where the left side of the heart doesn't develop properly and is too small. This results in not enough oxygenated blood getting through to the body.

Tricuspid atresia

Tricuspid atresia is where the tricuspid heart valve hasn't formed properly. The tricuspid valve separates the right-sided collecting chamber (atrium) and pumping chamber (ventricle). Blood can't flow properly between the chambers, which causes the right pumping chamber to be underdeveloped.

Tetralogy of Fallot

Tetralogy of Fallot is a rare combination of several defects.

The defects making up tetralogy of Fallot are:

• ventricular septal defect – a hole between the left and right ventricle
• pulmonary valve stenosis – narrowing of the pulmonary valve
• right ventricular hypertrophy – where the muscle of the right ventricle is thickened
• overriding aorta – where the aorta isn't in its usual position coming out of the heart

As a result of this combination of defects, oxygenated and non-oxygenated blood mixes, causing the overall amount of oxygen in the blood to be lower than normal. This may cause the baby to appear blue (known as cyanosis) at times.

Total (or partial) anomalous pulmonary venous connection (TAPVC)

TAPVC occurs when the 4 veins that take oxygenated blood from the lungs to the left side of the heart aren't connected in the normal way. Instead, they connect to the right side of the heart.

Sometimes, only some of the 4 veins are connected abnormally, which is known as partial anomalous pulmonary venous connection and may be associated with an atrial septal defect. More rarely, the veins are also narrowed, which can be fatal within a month after birth.

Transposition of the great arteries

Transposition of the great arteries is serious but rare.

It's where the pulmonary and aortic valves and the arteries they’re connected to (the pulmonary (lung) artery and the aorta (main body) artery) are "swapped over" and are connected to the wrong pumping chamber. This leads to blood that's low in oxygen being pumped around the body.

Truncus arteriosus

Truncus arteriosus is an uncommon type of congenital heart disease.

It's where the two main arteries (pulmonary artery and aorta) don't develop properly and remain as a single vessel. This results in too much blood flowing to the lungs which, over time, can cause breathing difficulties and damage the blood vessels inside the lungs.

Truncus arteriosus is usually fatal if it isn't treated.

Diagram of the heart

Credit:

ttsz / Thinkstock

Designua / ShutterStock

Congenital heart disease can have a range of symptoms, because the condition refers to several different types of heart defect.

General signs of congenital heart disease can include:

• a blue tinge to the skin (cyanosis)
• rapid breathing
• rapid heartbeat
• swelling in the legs, tummy and around the eyes
• shortness of breath in babies during feeding (making it hard for them to gain weight) and in older children and adults during exercise
• extreme tiredness and fatigue
• fainting during exercise
• swelling in the hands, ankles or feet

In more severe cases, these problems may develop shortly after birth. However, symptoms sometimes don't develop until the teenage years or early adulthood.

Read more about the types of congenital heart disease.

Complications

Children and adults with congenital heart disease can also develop a range of further problems, such as:

• problems with growth and development
• repeated respiratory tract infections (RTIs) – infections of the sinuses, throat, airways or lungs
• heart infection (endocarditis)
• pulmonary hypertension – raised blood pressure within the blood vessels that supply the lungs (pulmonary arteries)
• heart failure – where the heart is unable to efficiently pump enough blood around the body

Read more about the complications of congenital heart disease.

Congenital heart disease is caused when something disrupts the normal development of the heart.

It's thought that most cases occur when something affects the heart's development during the first 6 weeks of pregnancy. This is when the heart is developing from a simple tube-like structure into a shape more like a fully-formed heart.

While some things are known to increase the risk of congenital heart disease, no obvious cause is identified in most cases.

Increased risk

There are a number of things that can increase the chances of a child having congenital heart disease. Some of these are described below.

See types of congenital heart disease for more information on the different heart defects mentioned below.

Genetic conditions

Several genetic health conditions that a baby inherits from one or both parents can cause congenital heart disease. It's also recognised that certain types of congenital heart disease run in families.

Down's syndrome is the most widely-known genetic condition that can cause congenital heart disease. Children with Down's syndrome are born with a range of disabilities as the result of a genetic abnormality.

About half of all children with Down's syndrome have congenital heart disease. In many cases, this is a type of septal defect.

Other genetic conditions associated with congenital heart disease include:

• Turner syndrome – a genetic disorder that only affects females; many children with Turner syndrome will be born with congenital heart disease, which is usually a type of valve or artery narrowing problem.
• Noonan syndrome – a genetic disorder that can cause a wide range of potential symptoms, including pulmonary valve stenosis.

Maternal diabetes

Women with diabetes have a higher risk of giving birth to a baby with congenital heart disease than women who don't have diabetes.

This increased risk only applies to type 1 diabetes and type 2 diabetes. It doesn't apply to gestational diabetes, which can develop during pregnancy and usually disappears once the baby is born.

The increased risk is thought to be caused by high levels of the hormone insulin in the blood, which may interfere with the normal development of a foetus (the early stages of the baby developing in the womb).

Alcohol

If a pregnant woman drinks too much alcohol during pregnancy, it can have a poisonous effect on the tissue of the foetus. This is known as foetal alcohol syndrome.

It's common for children with foetal alcohol syndrome to have congenital heart disease – most often, ventricular or atrial septal defects.

The Department of Health and Social Care recommends that pregnant women shouldn't drink alcohol. If you choose to drink, you shouldn't drink more than 1 or 2 units of alcohol once or twice a week to minimise the risk to your unborn baby.

See Can I drink alcohol if I'm pregnant? for more information about alcohol and pregnancy.

Rubella

Rubella (German measles) is an infectious condition caused by a virus. It isn't usually a serious infection for adults or children, but it can severely affect an unborn baby if a mother develops a rubella infection during the first 8 to 10 weeks of pregnancy.

A rubella infection can cause multiple birth defects, including congenital heart disease. All women of childbearing age should be vaccinated against rubella. The vaccine is now given as part of the routine childhood vaccination schedule. Contact your GP for advice if you're not sure whether you've been vaccinated against rubella.

Flu (Influenza)

Women who get flu during the first trimester (3 months) of pregnancy are at greater risk of having a baby with congenital heart disease than the general population. The reasons for this are unclear.

The flu vaccine is recommended for all pregnant women.

Medications

There are several medications linked to an increased risk of a baby being born with congenital heart disease. These include:

• certain anti-seizure medications – such as benzodiazepines (for example diazepam)
• certain acne medications – such as isotretinoin and topical retinoids (see treating acne for more information)
• ibuprofen – women who take the painkiller ibuprofen when they are 30 or more weeks pregnant have an increased risk of having a baby with a heart problem

Paracetamol is a safer alternative to ibuprofen during pregnancy, although ideally you should avoid taking any medicines while you're pregnant, particularly during the first 3 months of pregnancy.

See Can I take ibuprofen when I'm pregnant? and Can I take paracetamol when I'm pregnant? for more information and advice.

Speak to your GP or pharmacist if you're unsure about which medications should be avoided during pregnancy.

Phenylketonuria (PKU)

Phenylketonuria (PKU) is a rare genetic condition present from birth. In PKU, the body can't break down a chemical called phenylalanine, which builds up in the blood and brain. This can cause learning and behavioural difficulties.

PKU can usually be effectively treated with a low-protein diet and dietary supplements. Pregnant mothers with PKU who don't do this are more likely to give birth to a baby with congenital heart disease than the general population. Read more about phenylketonuria and pregnancy.

Organic solvents

Women who are exposed to some organic solvents may be more likely to give birth to a baby with congenital heart disease than the general population.

Organic solvents are chemicals found in a wide range of products and substances, such as paint, nail polish and glue.

In many cases, congenital heart disease is diagnosed during pregnancy. However, a diagnosis may sometimes only be confirmed after the birth.

Diagnosis during pregnancy

Congenital heart disease may initially be suspected during a routine ultrasound scan of the baby in the womb. Specialist ultrasound, called foetal echocardiography, will then be carried out at around 18 to 22 weeks of the pregnancy to try to confirm the exact diagnosis.

This may also be undertaken if there's a family history of congenital heart disease or where there's an increased risk. Echocardiography is a type of ultrasound scan, where high-frequency sound waves are used to create an image of the heart.

However, it's not always possible to detect heart defects, particularly mild ones, using foetal echocardiography.

Read more about ultrasound scans during pregnancy.

Diagnosis after the birth

It's sometimes possible to diagnose a baby with congenital heart disease shortly after birth if some of the characteristic signs or symptoms of congenital heart disease, such as a blue tinge to the skin (cyanosis), are present.

Your baby's heart will be checked as part of the newborn physical examination. The examination involves observing your baby, feeling their pulse, and listening to their heart with a stethoscope. Heart murmurs are sometimes picked up.

However, some defects don't cause any noticeable symptoms for several months or even years. You should see your GP if you or your child shows signs of the condition. Further testing can usually help to confirm or rule out a diagnosis.

Further testing

Further tests may be used to diagnose congenital heart disease.

Echocardiography

Echocardiography is often used to check the inside of the heart. Heart problems that were missed during foetal echocardiography can sometimes be detected as a child develops.

Electrocardiogram

An electrocardiogram (ECG) is a test that measures the heart's electrical activity. Electrodes are placed on the skin around the heart and are connected to a computer. The computer analyses the electrical signals produced by the heart to assess how well it's beating.

Chest X-ray

A chest X-ray of the heart and lungs can be used to check whether there's an excess amount of blood in the lungs, or whether the heart is larger than normal. Both may be signs of heart disease.

Pulse oximetry

Pulse oximetry is a test that measures the amount of oxygen present in the blood.

The test involves placing a special sensor on the fingertip, ear or toe that sends out light waves. A computer is connected to the sensor and measures how the light waves are absorbed.

Oxygen can affect how the light waves are absorbed, so by analysing the results, the computer can quickly determine how much oxygen is present in the blood.

Cardiac catheterisation

Cardiac catheterisation is a useful way of obtaining more information about exactly how the blood is being pumped through the heart.

During the procedure, a small, flexible tube called a catheter is inserted into a blood vessel, usually through an artery and/or vein in the groin, neck or arm. The catheter is moved into the heart, guided by X-rays or sometimes an MRI scanner, and allows pressure measurements in different parts of the heart or lungs to be taken.

A coloured dye that shows up on X-rays can also be injected into the catheter. This is called an angiogram. The dye can be studied as it moves through the heart, allowing the shape and function of each heart chamber, vessels and the lung to be assessed.

Cardiac catheterisation is painless, because it's carried out under a general anaesthetic or a local anaesthetic.

Coping with a diagnosis

Being told that you or your child has a potentially complex and lifelong condition such as congenital heart disease can be a confusing and frightening experience, even if the condition is relatively mild.

It's natural to want to find out as much as possible about congenital heart disease, including the available treatments, and how it can affect your life.

Below is a list of charities and support groups you may find useful:

• The Children's Heart Federation – a group of charities dedicated to helping people affected by congenital heart disease
• The Down's Heart Group – a charity offering support and information on heart conditions associated with Down's syndrome
• British Heart Foundation – a national charity offering information, support and research into cardiovascular diseases
• Healthtalk.org – a website with a range of stories about children with different types of congenital heart disease, including interviews with their parents
• The Somerville Foundation – a national charity supporting young people and adults born with a heart condition

You may also want to find out what help is available for parents who care for children with complex conditions. Read tips for caring for a disabled child.

The specialist nurse at the congenital heart disease department at your hospital can point you in the direction of further information.

Treatment for congenital heart disease depends on the specific defect you or your child has.

The majority of congenital heart disease problems are mild heart defects and don't usually need to be treated, although it's likely that you'll have regular check-ups to monitor your health in an outpatient setting throughout life.

More severe heart defects usually require surgery or catheter intervention (where a thin hollow tube is inserted into the heart via an artery) and long-term monitoring of the heart throughout adult life by a congenital heart disease specialist.

In some cases, medications may be used to relieve symptoms or stabilise the condition before and/or after surgery or intervention.

These may include diuretics (water tablets) to remove fluid from the body and make breathing easier, and other medication, such as digoxin to slow down the heartbeat and increase the strength of the heart's pumping function.

See types of congenital heart disease for descriptions of the different defects below.

Aortic valve stenosis

The urgency for treatment depends on how narrow the valve is. Treatment may be needed immediately, or it could be delayed until the development of symptoms.

If treatment is required, a procedure called a balloon valvuloplasty is often the recommended treatment option in children and younger people.

During the procedure, a small tube (catheter) is passed through the blood vessels to the site of the narrowed valve. A balloon attached to the catheter is inflated, which helps to stretch or widen the valve and relieve any blockage in blood flow.

If balloon valvuloplasty is ineffective or unsuitable, it's usually necessary to remove and replace the valve using open heart surgery. This is where the surgeon makes a cut in the chest to access the heart.

There are several options for replacing aortic valves, including valves made from animal or human tissue, or your own pulmonary valve. If the pulmonary valve is used, it will be replaced at the same time with a donor pulmonary valve. This type of specialised surgery is known as the Ross procedure. In older children or adults, it's more likely that metal valves will be used.

Some people also develop a leak of the aortic valve which will require monitoring. If the leak starts to cause problems with the heart, the aortic valve will need to be replaced.

Coarctation of the aorta

If your child has the more serious form of coarctation of the aorta that develops shortly after birth, surgery to restore the flow of blood through the aorta is usually recommended in the first few days of life.

Several surgical techniques can be used, including:

• removing the narrowed section of the aorta and reconnecting the 2 remaining ends
• inserting a catheter into the aorta and widening it with a balloon or metal tube (stent)
• removing sections of blood vessels from other parts of your child's body and using them to create an aorta in the region of the coarctation or bypass around the site of the blockage (this is similar to a coronary artery bypass graft, which is used to treat heart disease)

Sometimes, older children and adults can develop a newly diagnosed coarctation or partial recurrence of the previous blockage. The main goal of treatment will be to control high blood pressure using a combination of diet, exercise and medication. Some people will need to have the narrowed section of the aorta widened with a balloon and stent.

Read more about treating high blood pressure.

Ebstein's anomaly

In many cases, Ebstein's anomaly is mild and doesn't require treatment. However, some people may need medicines to help control their heart rate and rhythm. Surgery to repair the abnormal tricuspid valve is usually recommended if the valve is very leaky.

If valve repair surgery is ineffective or unsuitable, a replacement valve may be implanted. If Ebstein's anomaly occurs along with an atrial septal defect, the hole will be closed at the same time.

Patent ductus arteriosus (PDA)

Some cases of PDA can be treated with medication shortly after birth.

There are 2 types of medication to effectively stimulate the closure of the duct responsible for PDA. These are indomethacin and a special form of ibuprofen.

If the PDA doesn't close with medication, the duct may be sealed with a coil or plug. These can be implanted using a catheter (keyhole surgery).

Sometimes the duct may need to be tied shut to close it. This is done using open heart surgery.

Pulmonary valve stenosis

Mild pulmonary valve stenosis doesn't require treatment, because it doesn't cause any symptoms or problems.

More severe cases of pulmonary valve stenosis usually require treatment, even if they cause few or no symptoms. This is because there's a high risk of heart failure in later life if it's not treated.

As with aortic valve stenosis, the main treatment for pulmonary valve stenosis is a balloon to the pulmonary valve (valvuloplasty). However, if this is ineffective or the valve isn't suitable for this treatment, surgery may be needed to open the valve (valvotomy) or replace the valve with an animal or human valve.

Some patients develop leaking of the pulmonary valve after treatment of pulmonary valve stenosis. This will require ongoing monitoring and if the leak starts to cause a problem with the heart then the valve will need to be replaced. This can be performed with open heart surgery or, increasingly, using catheter intervention which is a much less invasive procedure.

Septal defects

The treatment of ventricular and atrial septal defects depends on the size of the hole. No treatment will be required if your child has a small septal defect that doesn't cause any symptoms or stretch on the heart. These types of septal defects have an excellent outcome and don't pose a threat to your child's health.

If your child has a larger ventricular septal defect, surgery is usually recommended to close the hole.

A large atrial septal defect and some types of ventricular septal defect can be closed with a special device inserted with a catheter. If the defect is too big or not suitable for the device, surgery may be needed to close the hole.

Unlike open heart surgery, the catheter procedure doesn't cause any scarring and is associated with just a small bruise in the groin. Recovery is very quick. This procedure is undertaken in specialist units that treat congenital heart problems in children and a small number of additional adult centres.

Single ventricle defects

Tricuspid atresia and hypoplastic left heart syndrome are treated in much the same way.

Shortly after birth, your baby will be given an injection of medication called prostaglandin. This will encourage the mixing of oxygen-rich blood with oxygen-poor blood. The condition will then need to be treated using a 3-stage procedure.

The first stage is usually performed during the first few days of life. An artificial passage known as a shunt is created between the heart and lungs, so blood can get to the lungs. However, not all babies will need a shunt.

The second stage will be performed when your child is 3 to 6 months old. The surgeon will connect veins that carry oxygen-poor blood from the upper part of the body (superior vena cava) directly to your child's pulmonary artery. This will allow blood to flow into the lungs, where it can be filled with oxygen.

The final stage is usually performed when your child is 18 to 36 months old. It involves connecting the remaining lower body vein (inferior vena cava) to the pulmonary artery, effectively bypassing the heart.

Patients treated in this way with a single ventricle are complex and need lifelong specialist care. There may be significant complications after such complex surgery, which may limit the ability to exercise and shorten life expectancy. A heart transplant may be recommended for a small number of patients but is limited by the lack of available hearts for transplantation.

Read more about the heart transplant waiting list.

Tetralogy of Fallot

Tetralogy of Fallot is treated using surgery. If your baby is born with severe symptoms, surgery may be recommended soon after birth. If the symptoms are less severe, surgery will usually be carried out when your child is 4 to 6 months old.

During the operation, the surgeon will close the hole in the heart and open up the narrowing in the pulmonary valve.

Some patients develop leaking of the pulmonary valve after treatment of Tetralogy of Fallot. This will require ongoing monitoring and if the leak starts to cause a problem with the heart then the valve will need to be replaced. This can be performed with open heart surgery or, increasingly, using catheter intervention which is a much less invasive procedure.

Total anomalous pulmonary venous connection (TAPVC)

TAPVC is treated with surgery. During the procedure, the surgeon will reconnect the abnormally positioned veins into the correct position in the left atrium.

The timing of surgery will usually depend on whether your child's pulmonary vein (the vein connecting the lungs and heart) is also obstructed or narrowed.

If the pulmonary vein is obstructed, surgery will be performed shortly after birth. If the vein isn't obstructed, surgery can often be postponed until your child is a few weeks or months old.

Transposition of the great arteries

As with treatment for single ventricle defects, your baby will be given an injection of a medication called prostaglandin shortly after birth. This will prevent the passage between the aorta and pulmonary arteries (the ductus arteriosus) closing after birth.

Keeping the ductus arteriosus open means that oxygen-rich blood is able to mix with oxygen-poor blood, which should help relieve your baby's symptoms.

In some cases, it may also be necessary to use a catheter to create a temporary hole in the atrial septum (the wall separating the 2 upper chambers of the heart) to further encourage the mixing of blood.

Once your baby's health has stabilised, it's likely that surgery will be recommended. This should ideally be carried out during the first month of the baby's life. A surgical technique called arterial switch is used, which involves detaching the transposed arteries and reattaching them in the correct position.

Truncus arteriosus

Your baby may be given medicines to help stabilise their condition. Once your baby is in a stable condition, surgery will be used to treat truncus arteriosus. This is usually carried out within a few weeks of birth.

The abnormal blood vessel will be split to create 2 new blood vessels, and each one will be reconnected in the correct position.

Exercise

In the past, children with congenital heart disease were discouraged from exercising. However, exercise is now believed to improve health, boost self-esteem and help prevent problems developing in later life.

Even if your child can't do strenuous exercise, they can still benefit from a more limited programme of physical activity, such as walking or, in some cases, swimming.

Your child's heart specialist can give you more detailed advice about the right level of physical activity that's suitable for your child.

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

Developmental problems

Many children with more serious 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.

Learning difficulties can include:

• 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 involve coughing up phlegm and mucus
• wheezing
• rapid breathing
• chest tightness

Treatment for an RTI depends on the cause. Most are caused by viruses and do not require antibiotics. Infections caused by bacteria may 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 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 and have regular check-ups at the dentist.

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 particularly 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 risk of sudden cardiac death in people with a history of congenital heart disease, but this is uncommon. Identifying people at risk of sudden cardiac death is difficult, but those with a high risk of ventricular arrhythmias are usually fitted with an implantable cardioverter defibrillator.

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.

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) before getting pregnant.

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.

If you have congenital heart disease and become pregnant, your congenital heart specialist will usually arrange an echocardiogram (heart scan) for your baby approximately 20 weeks into your pregnancy. This is to check whether your baby has any evidence of congenital heart disease. This scan will be in addition to your usual antenatal ultrasound scans.

As so little is known about the causes of congenital heart disease, there's no guaranteed way of avoiding having a baby with the condition.

However, if you're pregnant, the following advice can help reduce the risk:

• Ensure you are vaccinated against rubella and flu (Influenza).
• Avoid drinking alcohol or taking medication.
• Take 400 micrograms of folic acid supplement a day during the first trimester (first 12 weeks) of your pregnancy – this lowers your risk of giving birth to a child with congenital heart disease, as well as several other types of birth defect.
• Check with your GP or pharmacist before you take any medication during pregnancy, including herbal remedies and medication that's available over the counter.
• Avoid contact with people who are known to have an infection.
• If you have diabetes, make sure it's controlled.
• Avoid exposure to organic solvents, such as those used in dry cleaning, paint thinners and nail polish remover.

See vitamins and nutrition in pregnancy, infections in pregnancy and your antenatal care for more information and advice.