Congenital heart disease

CONGENITAL HEART DISEASE

Congenital heart disease, or a congenital heart defect, is a heart abnormality present at birth. The problem can affect:

• the heart walls
• the heart valves
• the blood vessels

There are numerous types of congenital heart defects. They can range from simple conditions that don't cause symptoms to complex problems that cause severe, life-threatening symptoms.

Treatments and follow-up care for defects have improved drastically over the past few decades, so nearly all children with heart defects survive into adulthood. Some need continuous care for their heart defect throughout their lives. However, many go on to have active and productive lives despite their condition.

TYPES

Listed below are examples of different types of CHDs.

The types marked with a star (*) are considered critical CHDs.

• Atrial septal defect (ASD)
• Atrioventricular canal defect
• Bicuspid aortic valve
• Coarctation of the aorta
• Congenital heart defects in children
• Congenital mitral valve anomalies
• Double-outlet right ventricle
• Ebstein anomaly
• Eisenmenger syndrome
• Hypoplastic left heart syndrome
• Long QT syndrome
• Partial anomalous pulmonary venous return
• Patent ductus arteriosus (PDA)
• Patent foramen ovale
• Pulmonary atresia
• Pulmonary atresia with intact ventricular septum
• Pulmonary atresia with ventricular septum defect
• Pulmonary valve stenosis
• Tetralogy of Fallot
• Total anomalous pulmonary venous return
• Transposition of the great arteries
• Tricuspid atresia
• Truncus arteriosus
• Vascular rings
• Ventricular septal defect (VSD)
• Wolff-Parkinson-White (WPW) syndrome

CAUSES OF CONGENITAL HEART DISEASE

Most congenital heart defects have no known cause. Mothers will often wonder if something they did during the pregnancy caused the heart problem. In most cases, no specific cause can be found. Some heart problems do occur more often in families, so there may be a genetic link to some heart defects. Some heart problems are likely to occur if the mother had a disease while pregnant and was taking medicines, such as antiseizure medicines or the acne medicine isotretinoin. But, most of the time, there is no clear reason for the heart defect

Congenital heart problems range from simple to complex. Some heart problems can be watched by the baby's doctor and managed with medicines. Others will require surgery, sometimes as soon as in the first few hours after birth. A baby may even 'grow out' of some of the simpler heart problems, such as patent ductus arteriosus or atrial septal defect. These defects may simply close up on their own with growth. Other babies will have a combination of defects and require several operations throughout their lives.

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

SYMPTOMS

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.

RISK FACTORS

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.

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.

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 behavioral 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.

WHEN TO SEE A DOCTOR

If you're having worrisome symptoms, such as chest pain or shortness of breath, seek emergency medical attention.

If you have signs or symptoms of congenital heart disease or were treated for a congenital heart defect as a child, make an appointment to see your doctor.

DIAGNOSIS

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.

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

TREATMENT

The treatment for a congenital heart defect depends on the type and severity of the defect. Some babies have mild heart defects that heal on their own with time. Others may have severe defects that require extensive treatment. In these cases, treatment may include the following:

Medications

There are various medications that can help the heart work more efficiently. Some can also be used to prevent blood clots from forming or to control an irregular heartbeat.

Implantable Heart Devices

Some of the complications associated with congenital heart defects can be prevented with the use of certain devices, including pacemakers and implantable cardioverter defibrillators (ICDs). A pacemaker can help regulate an abnormal heart rate, and an ICD may correct life-threatening irregular heartbeats.

Catheter Procedures

Catheterization techniques allow doctors to repair certain congenital heart defects without surgically opening the chest and heart. During these procedures, the doctor will insert a thin tube into a vein in the leg and guide it up to the heart. Once the catheter is in the correct position, the doctor will use small tools threaded through the catheter to correct the defect.

Open-Heart Surgery

This type of surgery may be needed if catheter procedures aren't enough to repair a congenital heart defect. A surgeon may perform open-heart surgery to close holes in the heart, repair heart valves, or widen blood vessels.

Heart Transplant

In the rare cases in which a congenital heart defect is too complex to fix, a heart transplant may be needed. During this procedure, the child's heart is replaced with a healthy heart from a donor.

PREVENTION

Women who are pregnant or plan on becoming pregnant can take certain precautions to lower their risk of giving birth to a baby with a congenital heart defect:

If you're planning on becoming pregnant, talk to your doctor about any prescription or over-the-counter medications you're taking.

If you have diabetes, make sure your blood sugar levels are under control before becoming pregnant. It's also important to work with your doctor to manage the disease while pregnant.

If you weren't vaccinated against rubella, or German measles, avoid exposure to the disease and speak with your doctor about prevention options.

If you have a family history of congenital heart defects, ask your doctor about genetic screening. Certain genes may contribute to abnormal heart development.

Avoid drinking alcohol and using illegal drugs during pregnancy.

LIVING WITH A CONGENITAL HEART DEFECT

Many adults with some types of CHDs need to be cared for by physicians with additional training in caring for adults with CHDs.

As medical care and treatment have improved, babies and children with congenital heart defects (CHDs) are living longer and healthier lives. Most are now living into adulthood. Ongoing, appropriate medical care can help children and adults with a CHD live as healthy as possible.

Health Care

It is important for parents of children with a heart defect and adults living with a heart defect to talk with a heart doctor (cardiologist) regularly. Regular visits with a cardiologist are important, because they allow the parents of children with heart defects to make the best possible choices for the health of their child. These visits also allow adults living with a heart defect to make the best possible choices for their own health.

Children and adults with CHDs can help with their health care by knowing their medical history, including the:

• Type(s) of heart defect(s) they have.
• Procedures or surgeries they have had performed.
• Medicines and doses of these medicines that they are prescribed currently and were prescribed in the past.
• Type(s) of medical care they are receiving now.

As children transition to adult health care, it is important to notify any new healthcare provider(s) about the child's CHD. Ongoing appropriate medical care for their specific heart defect will help children and adults with a CHD to live as healthy a life as possible.