What is congenital cardiovascular disease or congenital heart disease?
Congenital means inborn or existing at birth. Among the terms you may hear are congenital heart defect, congenital heart disease and congenital cardiovascular disease. The word "defect" is more accurate than "disease." A congenital cardiovascular defect occurs when the heart or blood vessels near the heart don't develop normally before birth.

What causes congenital cardiovascular defects?
Congenital cardiovascular defects are present in about one percent of live births and are the most frequent congenital malformations in new-borns. In Ireland, there are about 500 - 600 babies born every year with a congenital heart defect. In most cases scientists don't know why they occur. Sometimes a viral infection causes serious problems. German measles (also called rubella) is an example. If a mother contracts German measles during pregnancy, it can interfere with the development of the baby's heart or produce other malformations. Other viral diseases also may produce congenital defects.

Heredity sometimes plays a role in congenital cardiovascular disease. More than one child in a family may have a congenital cardiovascular defect, but this rarely occurs. Certain conditions affecting multiple organs, such as Down's syndrome, can involve the heart, too. Some prescription drugs and over-the-counter medicines, as well as alcohol and "street" drugs, may increase the risk of having a baby with a heart defect.

Other factors that affect the heart's development are under study. The fact is that we don't know what causes most congenital cardiovascular defects.

What is a Murmur?
The word "murmur" literally means "noise". The blood flowing through the heart may make a noise (murmur) which can be heard with a stethoscope. Some of these murmurs are caused by the normal flow of blood (innocent murmurs - see below). Others are caused by abnormal blood flow, for instance through a hole in the heart, or across a narrowed passageway or valve (organic murmur). Doctors may be able to identify a particular type of congenital heart defect simply by the particular sound and location of the murmur. These days however, in addition to a careful clinical eaxamination, the doctor has the benefit of a variety of precise diagnosic equipment, such as echocardiography (ultrasound scanner). This has made the diagnosis of congenital heart defects much simpler and more precise.

What is an Innocent Murmur?
Blood flowing through the normal heart and blood vessels does so remarkably quietly in most people. Some of us with perfectly normal hearts have slightly noisier blood flow through the heart and this noise can be heard with a stethoscope. This normal noise is referred to as an innocent murmur. It is heard most often in young children, because they are thin and their circulation is active. The more active the circulation (following exercise or during a fever), the louder the murmur. It is important to emphasise that innocent murmurs, even quite loud ones, are perfectly normal and do not require any particular precautions or follow-up by the cardiologist. The doctor often will be able to identify whether a murmur is innocent (normal) or not simply by listening. If there is doubt, a specialist opinion and investigations (as described above) may be needed.

What are the types of congenital heart defects?
Most heart defects either:

1. Obstruct blood flow in the heart or vessels near it or
2. Cause blood to flow through the heart in an abnormal pattern. Rarely defects occur in which only one ventricle (single ventricle) is present, or both the pulmonary artery and aorta arise from the same ventricle (double outlet ventricle).
3. Rare defects occur when the right or left side of the heart is incompletely formed - hypoplastic right or left heart.

Another simple and common classification divides congenital heart defects into:
i) Acyanotic (Pink) Heart Defects and
ii) Cyanotic (Blue) Heart Defects.

Acyanotic (Pink) Heart Defects
Patent ductus arteriosus (PDA)

Obstruction Defects

Pulmonary stenosis (PS)
Aortic stenosis (AS)
Coarctation of the aorta
Bicuspid aortic valve
Subaortic stenosis
Ebstein's anomaly
Septal Defects
Atrial septal defect (ASD)
Ventricular septal defect (VSD)
Eisenmenger's syndrome
Atrioventricular septal defect (AVSD) - also called AV Canal

Cyanotic Heart Defects

Tetralogy of Fallot
Transposition of the great arteries (TGA)
Tricuspid atresia
Pulmonary atresia
Truncus arteriosus
Total anomolous pulmonary venous connection (TAPVC)
Hypoplastic left heart syndrome

Cyanotic Heart Defects
With cyanotic heart defects, blood pumped to the body contains less-than-normal amounts of oxygen. This results in a condition called cyanosis, a blue discoloration of the skin. The term "blue babies" is often applied to infants with cyanosis.

Examples of cyanotic defects are tetralogy of Fallot, transposition of the great arteries, tricuspid atresia, pulmonary atresia, truncus arteriosus and total anomalous pulmonary venous connection.

Tetralogy of Fallot is the most common form of cyanotic congenital heart disease. The word "tetralogy" means "four components". The two major ones are: 1) a large hole, or ventricular septal defect, that allows blood to pass from the right ventricle to the left ventricle without going through the lungs, and 2) a narrowing (stenosis) at or just beneath the pulmonary valve. This narrowing partially blocks the flow of blood from the right side of the heart to the lungs. The other two components are: 3) the right ventricle is more muscular than normal, and 4) the aorta lies directly over the ventricular septal defect.

This results in cyanosis (blueness), which may appear soon after birth, in infancy or later in childhood. These "blue babies" may have sudden episodes of severe cyanosis with rapid breathing (cyanotic spells). They may even become unconscious and need urgent medical attention. During exercise, older children may become short of breath and faint. These symptoms occur because not enough blood flows to the lungs to supply the child's body with oxygen. Talk to your doctor as a matter of urgency if you think your child has tetralogy and may be having cyanotic spells.

Some infants with severe tetralogy of Fallot may need an operation to give temporary relief by increasing blood flow to the lungs with a shunt. This is achieved by making a connection between the aorta and the pulmonary artery. Then some blood from the aorta flows into the lungs to get more oxygen. This reduces the cyanosis and allows the child to grow and develop until the problem can be fixed when the child is older.

Most children with tetralogy of Fallot have open-heart surgery before school age. The operation involves closing the ventricular septal defect and removing the obstructing muscle. After surgery the long-term outlook varies, depending largely on how severe the defects were before surgery. Lifelong medical follow-up is needed.

People with tetralogy of Fallot, before and after treatment, are at risk for getting an infection within the aorta or the heart valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Transposition of the great arteries - The positions of the pulmonary artery and the aorta are reversed. The aorta is connected to the right ventricle, so most of the blood returning to the heart from the body is pumped back out without first going to the lungs. The pulmonary artery is connected to the left ventricle, so that most of the blood returning from the lungs goes back to the lungs again.

Infants born with transposition survive only if they have one or more connections that let oxygen-rich blood reach the body. One such connection may be a hole between the two atria, called atrial septal defect, or between the two ventricles, called ventricular septal defect. Another may be a vessel connecting the pulmonary artery with the aorta, called patent ductus arteriosus. Most babies with transposition of the great arteries are extremely blue (cyanotic) soon after birth because these connections are inadequate.

To improve the body's oxygen supply, a special procedure called balloon atrial septostomy is used. Two general types of surgery may be used to help fix the transposition. One is a venous switch or intra-atrial baffle procedure that creates a tunnel inside the atria. Another is an arterial switch. After surgery, the long-term outlook is varies quite a bit. It depends largely on how severe the defects were before surgery. Lifelong follow-up is needed

People with transposition of the great arteries, before and after treatment, are at risk for getting an infection on the heart's walls or valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Tricuspid atresia - In this condition, there's no tricuspid valve. That means no blood can flow from the right atrium to the right ventricle. As a result, the right ventricle is small and not fully developed. The child's survival depends on there being an opening in the wall between the atria called an atrial septal defect and usually an opening in the wall between the two ventricles called a ventricular septal defect. Because the circulation is abnormal, the blood cannot get enough oxygen, and the child looks blue (cyanotic).

Often in these cases a surgical shunting procedure is needed to increase blood flow to the lungs. This reduces the cyanosis. Some children with tricuspid atresia have too much blood flowing to the lungs. They may need a procedure (pulmonary artery banding) to reduce blood flow to the lungs. Other children with tricuspid atresia may have a more functional repair (Fontan procedure). Children with tricuspid atresia require lifelong follow-up by a paediatric cardiologist.

People with tricuspid atresia, before and after treatment, are at risk for getting an infection of the valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Pulmonary atresia - No pulmonary valve exists, so blood can't flow from the right ventricle into the pulmonary artery and on to the lungs. The right ventricle acts as a blind pouch that may stay small and not well developed. The tricuspid valve is often poorly developed, too.

An opening in the atrial septum lets blood exit the right atrium, so venous (bluish) blood mixes with the oxygen-rich (red) blood in the left atrium. The left ventricle pumps this mixture of oxygen-poor blood into the aorta and out to the body. The baby appears blue (cyanotic) because there's less oxygen in the blood circulating through the arteries. The only source of lung blood flow is the patent ductus arteriosus (PDA), an open passageway between the pulmonary artery and the aorta. If the PDA narrows or closes, the lung blood flow is reduced to critically low levels. This can cause very severe cyanosis.

Early treatment often includes using a drug to keep the PDA from closing. A surgeon can create a shunt between the aorta and the pulmonary artery to help increase blood flow to the lungs. A more complete repair depends on the size of the pulmonary artery and right ventricle. If the pulmonary artery and right ventricle are very small, it may not be possible to correct the defect with surgery. In cases where the pulmonary artery and right ventricle are more normal size, open-heart surgery may produce a good improvement in how the heart works.

If the right ventricle stays too small to be a good pumping chamber, then the surgeon can connect the right atrium directly to the pulmonary artery. The atrial defect also can be closed to relieve the cyanosis. This is called a Fontan procedure. Children with pulmonary atresia require lifelong follow-up by a paediatric cardiologist.

People with pulmonary atresia, before and after treatment, are at risk for getting an infection on the heart's walls or valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Truncus arteriosus - This is a complex and rare malformation where only one artery arises from the heart and forms the aorta and pulmonary artery. Surgery for this condition is not always possible. If feasible, surgery is usually required early in life. It includes closing a large ventricular septal defect within the heart, detaching the pulmonary arteries from the large common artery, and connecting the pulmonary arteries to the right ventricle with a tube graft. Children with truncus arteriosus need lifelong follow-up to see how well the heart is working.

People with truncus arteriosus, before and after treatment, are at risk for getting an infection on the heart's walls or valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Total anomalous pulmonary venous connection (TAPVC)- The pulmonary veins that bring oxygen-rich (red) blood from the lungs back to the heart aren't connected to the left atrium. Instead, the pulmonary veins drain through abnormal connections to the right atrium.

In the right atrium, oxygen-rich (red) blood from the pulmonary veins mixes with venous (bluish) blood from the body. Part of this mixture passes through the atrial septum (atrial septal defect) into the left atrium. From there it goes into the left ventricle, to the aorta and out to the body. The rest of the poorly oxygenated mixture flows through the right ventricle, into the pulmonary artery and on to the lungs. The blood passing through the aorta to the body doesn't have enough oxygen, which causes the child to look blue (cyanotic).

This defect must be surgically repaired in early infancy. Depending on the exact anatomy, the surgery can be very complicated and difficult. The pulmonary veins are reconnected to the left atrium and the atrial septal defect is closed. When surgical repair is done in early infancy, the long-term outlook is very good. Still, lifelong follow-up is needed to make certain that any remaining problems, such as an obstruction in the pulmonary veins or irregularities in heart rhythm, are treated properly. Lifelong follow-up is important to make certain that a blockage doesn't develop in the pulmonary veins or where they're attached to the left atrium. Heart rhythm irregularities (arrhythmias) also may occur at any time after surgery.

Hypoplastic left heart syndrome
In hypoplastic left heart syndrome, the entire left side of the heart - including the aorta, aortic valve, left ventricle and mitral valve - is underdeveloped. Blood returning from the lungs must flow through an opening in the wall between the atria, called an atrial septal defect. The right ventricle pumps the blood into the pulmonary artery and blood reaches the aorta through a patent ductus arteriosus (see above).

The baby often seems normal at birth, but will come to medical attention within a few days of birth as the ductus closes. Babies with this syndrome become ashen, have rapid and difficult breathing and have difficulty feeding. This heart defect is usually fatal within the first days or months of life without treatment.

Although this defect is not correctable, some babies can be treated with a series of operations, often leading to a heart transplant later in childhood. Until an operation is performed, the ductus is kept open by intravenous (IV) medication. Because these operations are complex and different for each patient, you need to discuss all the medical and surgical options with your child's doctor. Your doctor will help you decide which is best for your baby.

If you and your child's doctor elect to undergo surgery, the surgery will be performed in several stages. The first stage, called the Norwood procedure, allows the right ventricle to pump blood to both the lungs and the body. It must be performed soon after birth. The final stage(s) has many names including bi-directional Glenn, Fontan operation and lateral tunnel. These operations create a connection between the veins returning blue blood to the heart and the pulmonary artery. The overall goal of the operation is to allow the right ventricle to pump only oxygenated blood to the body and to prevent or reduce mixing of the red and blue blood. Some infants require several intermediate operations to achieve the final goal.

At our current stage of knowledge, most doctors believe that the operations described above for hypoplastic left heart are palliative (temporary) and that a heart transplant will sooner or later be required, perhaps in later chilhood or early adulthood. Although it does provide the child with a heart that has a normal structure, the infant will require lifelong supervision and medications to prevent rejection. Many other problems related to transplants could develop, and you should discuss these with your doctor.

Children with hypoplastic left heart syndrome require lifelong follow-up by a paediatric cardiologist for repeated checks of how their heart is working. Virtually all the children will require heart medicines.

People with hypoplastic left heart syndrome, before and after treatment, are at risk for getting an infection on the heart's valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures. Good dental hygiene also lowers the risk of endocarditis. For more information about dental hygiene and preventing endocarditis, ask your paediatric cardiologist and your dentist.

Acyanotic Heart Defects
All the conditions discussed here are referred to as acyanotic (pink) defects, that is they don’t generally cause the infant or child to become blue.

Patent ductus arteriosus (P.D.A.)
This defect allows blood to mix between the pulmonary artery and the aorta. Before birth there's an open passageway (the ductus arteriosus) between these two blood vessels. Normally this closes within a few hours of birth. When this doesn't happen, however, some blood that should flow through the aorta and on to nourish the body returns to the lungs. A ductus that doesn't close is quite common in premature infants but less common in full-term babies. If the ductus arteriosus is large, a child may tire quickly, grow slowly, catch pneumonia easily and breathe rapidly. In some children symptoms may not occur until after the first weeks or months of life. If the ductus arteriosus is small, the child seems well. If surgery is needed, the surgeon can close the ductus arteriosus by tying it, without opening the heart. If there's no other defect, this restores the circulation to normal. A new technique has been developed allowing the cardiologist to close the PDA at cardiac catheterization using an implantable coil or plug. However, not all infants and children with PDAs are suitable for this new technique. If the baby is very premature, it is sometimes possible to close a PDA using a medicine called Indomethacin.

Obstruction defects
An obstruction (stenosis) is a narrowing that partly or completely blocks the flow of blood. Obstructions can occur in heart valves, arteries or veins.

The three most common forms of obstructed blood flow are: pulmonary stenosis, aortic stenosis and coarctation of the aorta. Related but less common forms include bicuspid aortic valve, subaortic stenosis and Ebstein's anomaly.

Pulmonary stenosis
The pulmonary valve is between the right ventricle and the pulmonary artery. It opens to allow blood to flow from the right ventricle to the lungs. A defective pulmonary valve that does not open properly is called pulmonary stenosis. That means the right ventricle must pump harder than normal to overcome the obstruction.

If the stenosis is severe, especially in babies, some cyanosis (blueness) may occur. Older children usually have no symptoms. Treatment is needed when the pressure in the right ventricle is higher than normal. In most children the obstruction can be relieved by a procedure called balloon valvuloplasty. In other patients, open-heart surgery may be needed. During surgery, the valve can usually be opened satisfactorily. The outlook after balloon valvuloplasty or surgery is favourable, but follow-up is required to determine if heart function returns to normal.

People with pulmonary stenosis, before and after treatment, are at risk for getting an infection of the valve (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Aortic stenosis (A.S.)
The aortic valve, between the left ventricle and the aorta, is narrowed. This makes it hard for the heart to pump blood to the body. Aortic stenosis occurs when the aortic valve didn't form properly. A normal valve has three leaflets or cusps, but a stenotic valve may have only one cusp (unicuspid) or two cusps (bicuspid), which are thick and stiff. (See bicuspid aortic valve below.)

Sometimes stenosis is severe and symptoms may occur in newborns or in infancy. Otherwise, most children with aortic stenosis have no symptoms. In some children, chest pain, unusual tiring, dizziness or fainting may occur. The need for surgery depends on how bad the stenosis is. In children, a surgeon may be able to enlarge the valve opening. Although surgery may improve the stenosis, the valve remains deformed. Eventually, the valve will usually need to be replaced with an artificial one.

A procedure called balloon valvuloplasty has been successful in some infants and children with aortic stenosis. The long-term results of this procedure are still being studied. Children with aortic stenosis need lifelong medical follow-up. Even mild stenosis may worsen over time, and surgical relief of a blockage is sometimes incomplete. Check with your paediatric cardiologist about limiting some kinds of exercise.

People with aortic stenosis, before and after treatment, are at risk for getting an infection of the valve (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Coarctation of the aorta
The aorta, the main artery carrying blood from the heart to the body, is pinched or constricted. This obstructs blood flow to the lower part of the body and increases blood pressure above the constriction. Usually there are no symptoms at birth, but they can develop as early as the first week after birth. A baby may develop congestive heart failure or high blood pressure that requires early surgery. Otherwise, surgery usually can be delayed. A child with a severe coarctation should have surgery in early childhood. This prevents problems such as developing high blood pressure as an adult.

The outlook after surgery is favourable, but long-term follow-up is required. Rarely, coarctation of the aorta may recur. Some of these cases can be treated by balloon angioplasty. The long-term results of this procedure are still being studied. Also, blood pressure may stay high even when the aorta's narrowing has been repaired.

People with coarctation of the aorta, before and after treatment, are at risk for getting an infection within the aorta or the heart valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Bicuspid aortic valve
This is probably the most common congenital heart defect. The normal aortic valve has three flaps, or cusps, that open and close. A bicuspid valve has only two flaps, rather than three. There may be no symptoms in childhood, but by adulthood (often middle age or older) the valve can become stenotic (narrowed), making it harder for blood to pass through it, or regurgitant (allowing blood to leak backward through it). Treatment depends on how well the valve functions.

People with bicuspid aortic valve, before and after treatment, are at risk for getting an infection within the aorta or the heart valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Subaortic stenosis
Stenosis means constriction or narrowing. Subaortic means below the aorta. Subaortic stenosis refers to a narrowing of the left ventricle just below the aortic valve, which blood passes through to go into the aorta. This stenosis limits the flow of blood out of the left ventricle. This condition may be congenital or may be due to a particular form of cardiomyopathy known as Hypertrophic Obstructive Cardiomyopathy (HOCM). Treatment depends on the cause and the severity of the narrowing. It can include drugs or surgery.

People with subaortic stenosis, before and after treatment, are at risk for getting an infection within the aorta or the heart valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Ebstein's anomaly is a congenital downward displacement of the tricuspid valve (located between the upper and lower chambers on the right side of the heart) into the right bottom chamber of the heart (or right ventricle). It is usually associated with an atrial septal defect (see below). It may occur as a very mild problem or as a life threatening defect depending on the degree of abnormality of the tricuspid valve. It is sometimes associated with abnormal heart rhythms.

People with Ebstein's anomaly, before and after treatment, are at risk for getting an infection within the heart valve (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Septal defects
Some congenital cardiovascular defects allow blood to flow between the right and left chambers of the heart. This happens when a baby is born with an opening between the wall (septum) that separates the right and left sides of the heart. This defect is sometimes called "a hole in the heart."

The two most common types of this defect are atrial septal defect and ventricular septal defect. Two variations are Eisenmenger's syndrome and atrioventricular septal defect.

Atrial septal defect (A.S.D.)
An opening exists between the two upper chambers of the heart. This allows some blood from the left atrium (blood that's already been to the lungs) to return via the hole to the right atrium instead of flowing through the left ventricle, out the aorta and to the body. Many children with ASD have few, if any, symptoms. Closing the atrial defect by open-heart surgery in childhood can prevent serious problems later in life. Recently a new technique has allowed cardiologists to close some ASDs at cardiac catheterization using a specially designed detachable plug, avoiding the need for open heart surgery. This new procedure is still being evaluated.

Ventricular septal defect (V.S.D.)
An opening exists between the two lower chambers of the heart. Some blood that has returned from the lungs and has been pumped into the left ventricle flows to the right ventricle through the hole instead of being pumped into the aorta. The heart, which has to pump extra blood, is over-worked and may enlarge. If the opening is small, it doesn't strain the heart. In that case, the only abnormal finding is a loud murmur. But if the opening is large, open-heart surgery is recommended to close the hole and prevent serious problems. Some babies with a large ventricular septal defect don't grow normally and may become undernourished. Babies with VSD may develop severe symptoms or high blood pressure in their lungs. Repairing a ventricular septal defect with surgery usually restores the blood circulation to normal. The long-term outlook is good, but long-term follow-up is required.

People with a ventricular septal defect are at risk for getting an infection of the heart's walls or valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Eisenmenger's Syndrome is a septal defect (VSD, PDA, AVSD or rarely ASD) coupled with high blood pressure in the lungs, the passage of blood from the right side of the heart to the left (right to left shunt), an enlarged right ventricle and a bluish discoloration of the skin called cyanosis. Heart surgery is rarely of benefit but symptoms can be improved with medical treatment.

People with Eisenmenger's Syndrome are at risk of getting an infection within the aorta or the heart valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Atrioventricular Septal Defect (AVSD) (also called endocardial cushion defect or atrioventricular canal defect) - A large hole in the centre of the heart exists where the wall between the upper chambers joins the wall between the lower chambers. Also, the tricuspid and mitral valves that normally separate the heart's upper and lower chambers aren't formed as individual valves. Instead, a single large valve forms that crosses the defect.

The large opening in the centre of the heart lets oxygen-rich (red) blood from the heart's left side - blood that's just gone through the lungs - pass into the heart's right side. There, the oxygen-rich blood, along with venous (bluish) blood from the body, is sent back to the lungs. The heart must pump an extra amount of blood and may enlarge. Most babies with an atrioventricular canal don't grow normally and may become undernourished. Because of the large amount of blood flowing to the lungs, high blood pressure may occur there and damage the blood vessels.

In some babies with AVSD the common valve between the upper and lower chambers doesn't close properly. This lets blood leak backward from the heart's lower chambers to the upper ones. This leak, called regurgitation or insufficiency, can occur on the right side, left side, or both sides of the heart. With a valve leak, the heart pumps an extra amount of blood, becomes overworked and enlarges.

In babies with severe symptoms or high blood pressure in the lungs, surgery must usually be done in infancy. The surgeon closes the large hole with one or two patches and divides the single valve between the heart's upper and lower chambers to make two separate valves. Surgical repair of an atrioventricular septal defect usually restores the blood circulation to normal. However, the reconstructed valve may not work normally.

Rarely, the defect may be too complex to repair in infancy. In this case, the surgeon may do a procedure called pulmonary artery banding to reduce the blood flow and high pressure in the lungs. When a child is older, the band is removed and corrective surgery is done. More medical or surgical treatment is sometimes needed.

People with atrioventricular septal defect, before and after treatment, are at risk of getting an infection within the heart's walls or valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.

Congenital Cardiovascular Disease Treatments
Many children with congenital heart and blood vessel defects may need medical treatment such as diuretics, digoxin or other drugs. Diuretics (such as frusemide, chlorothiazide, spironolactone and amiloride) promote the excretion of water and salts by increasing the rate that urine forms. Digoxin makes the contraction of the heart muscle stronger, slows the rate of heartbeats and helps remove extra fluid from body tissues. Captopril dilates blood vessels around the body allowing the heart to pump against less resistance. Anti-arrhythmic drugs (Digoxin, Propranolol,Flecainide, Amiodorone, Sotalol, Verapamil etc.) may be required to prevent the heart developing abnormal, rapid rhythm disturbances (arrhythmias). Some children may need surgery.

What surgical procedures are used?
The following surgical procedures are described in this section:

Arterial switch
Balloon atrial septostomy
Balloon valvuloplasty
Stent procedure
Device closure (PDA, ASD)
Fontan procedure or operation
Pulmonary artery banding
Ross procedure
Shunt or shunting procedure
Venous switch or intra-atrial baffle

Arterial switch - A surgical procedure in which the major arteries are switched in babies with transposition of the great arteries. The aorta is connected to the left ventricle, which pumps oxygen-rich (red) blood to the body. The pulmonary artery is connected to the right ventricle, which pumps venous (bluish) blood to the lungs. This arterial switch procedure may be done in the first few weeks after birth or, depending on various factors, slightly later. If there's a large ventricular septal defect or other defects related to the transposition, the repair gets more complicated. Then other surgical procedures may be needed.

Balloon atrial septostomy - A special procedure used during heart catheterization to improve the body's oxygen supply in babies with transposition of the great arteries. It enlarges the atrial opening and helps the baby by reducing the cyanosis (blueness).

Balloon valvuloplasty - A procedure in which a special catheter (a tube introduced into a blood vessel and threaded to the heart) containing a deflated balloon is inserted into the opening of a narrowed heart valve. When the balloon is inflated, the valve is stretched open; then the balloon is removed. The procedure is used with favourable results to improve blood flow in pulmonary stenosis. It is also used in some cases of aortic stenosis, coarctation of the aorta and other blood vessel narrowings, where the long-term results are still being studied.

Stent Procedure - This procedure often accompanies a Balloon Valvuloplasty (described above). An expandable stainless steel wire cylinder is inserted across a stenosis (narrowing) inside the heart or blood vessel. It is designed to open up the narrowing and to keep it from re-narrowing. This is a new technique which can usually be carried out at cardiac catheterization, thus avoiding conventional open surgery. The long term results are being assessed.

Device Closure - PDA or ASD - Recent technological developments have allowed cardiologists to perform some procedures in the cardiac catheterization laboratory, which previously required conventional surgery. A variety of plugs or coils are now available designed specifically to close these septal defects. A catheter (a hollow soft plastic tube) is inserted into a vein or artery in the leg and advanced to the heart, as with conventional cardiac catheterization. Through the catheter, a collapsible coil or plug is placed across the defect, thus repairing it. When the doctor is satisfied that it is the correct place, the device is detached. The body then begins the process of covering over the device with its own natural lining (endothelium). Often, the child can go home the following day.

Again, it is important to emphasise that a) although these appear to be exciting advances, the techniques are new and doctors will need to study the long term results; b) not all children with a PDA or ASD will be suitable for these procedures.

Fontan procedure or operation - A surgical procedure in which the right atrium is connected to the pulmonary artery either directly or with a conduit. This allows blood to bypass an incomplete or underdeveloped right ventricle, as in tricuspid atresia and pulmonary atresia. The atrial defect is also closed to relieve cyanosis (blueness).

Pulmonary artery banding - A procedure in which a surgeon places a band around the pulmonary artery to narrow it and reduce the blood flow and high pressure in the lungs. This is done to relieve such defects as ventricular septal defect, atrioventricular canal defect, and tricuspid atresia.

When the child is older, doctors can remove the band and fix the defect with open-heart surgery.

Ross procedure - A procedure in which a person's diseased or abnormal aortic valve is replaced with the patient's own pulmonary valve (pulmonary autograft). A homograft valve (valve from a human donor) is then placed where the pulmonary valve was.

Shunt or shunting procedure - The operation of forming a passage between blood vessels to divert blood from one part of the body to another. It is used to reduce the cyanosis (blueness) in infants with severe tetralogy of Fallot and those with tricuspid atresia or pulmonary atresia. The most common types are the Blalock-Taussig (BT) shunt and the Glenn shunt.

Venous switch or intra-atrial baffle - A procedure that creates a tunnel inside the atria to help correct transposition of the great arteries. It redirects oxygen-rich (red) blood to the right ventricle and aorta, and redirects venous (bluish) blood to the left ventricle and pulmonary artery. In the Mustard procedure, the intra-atrial baffle is made of tissue from the pericardium. In the Senning procedure, the intra-atrial baffle is made of flaps from the atrial wall.