WHAT IS CONGENITAL HEART DISEASE / DEFECT?
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 IS BLUE BABY DEFECT?
A blue baby is an infant born with a type of Congenital Heart Disease that causes the infant’s skin to have a bluish tint (cynosis).
Central cyanosis is a condition in which there is too much oxygen–poor blood traveling through the arteries, which normally carry only oxygen–rich blood to nourish the body. In technical terms, cyanosis is diagnosed when the level of reduced (desaturated) hemoglobin exceeds 3 grams per deciliter (g/dl) of blood in the capilliary bed – the network of tiny arteries where oxygen exchange takes place throughout the body.
Not all cyanosis is caused by congenital heart defects.
Peripheral cyanosis, or a slight bluish tinge in the extremities, may occur in healthy, fair–skinned babies. This type of cyanosis is caused when the degree of oxygen saturation in the blood is normal, but there is increased extraction of oxygen from the blood because the blood is moving too slowly through the capillaries. This causes some tissues to receive too little oxygen. Causes of peripheral cyanosis include constriction of blood vessels due to cold, obstructions in the veins, high blood pressure in the veins and other factors.
Cyanosis may also be caused by lung abnormalities and blood conditions that somehow impede the delivery of oxygen to the tissues and organs of the body.
WHAT ARE THE SIGNS AND SYMPTOMS OF CONGENITAL HEART DEFECT?
Aside from the bluish tint of the skin, nails, lips, tongue or other parts of the body, signs and symptoms of a blue baby include:
Some of the cyanotic heart defects will create what’s known as differential cyanosis. This condition results when one half of the body, either the upper or lower half, is healthy and pink and the other half is bluish. This can help the physician narrow down the possible causes of cyanosis, if the causes aren’t known already.
WHAT ARE THE CAUSES OF CONGENITAL CARDIOVASULAR DISEASE?
Congenital cardiovascular defects are present in about 1 percent of live births. They’re the most common congenital malformations in newborns. In most cases scientists don’t know why they occur. Some of the so far known causes are:
Researchers are studying other factors.
WHAT ARE THE TYPES OF CONGENITAL DISEASES?
In most of the cases blood flow in the heart or vessels near is obstructed or blood flow is routed in an abnormal fashion. Other defects could be:
WHAT ARE DEFECTS CAUSED BY OBSTRUCTION IN BLOOD FLOW?
An obstruction is a narrowing that partly or completely blocks the flow of blood. Obstructions called stenoses can occur in heart valves, arteries or veins.
The three most common forms 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.
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. Others may need open-heart surgery. Surgery usually opens the valve satisfactorily. The outlook after balloon valvuloplasty or surgery is favorable, 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.
Sometimes stenosis is severe and symptoms occur in infancy. Otherwise, most children with aortic stenosis have no symptoms. Some children may have chest pain, unusual tiring, dizziness or fainting. The need for surgery depends on how bad the stenosis is. In children, a surgeon may be able to enlarge the valve opening. Surgery may improve the stenosis, but the valve remains deformed. Eventually, the valve may need to be replaced with an artificial one.
Balloon valvuloplasty has been used in some 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 pediatric 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.
The outlook after surgery is favorable, 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 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.
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.
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.
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 let blood flow to the heart’s right and left chambers. 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 complex and atrioventricular canal defect.
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 normal blood circulation. 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. After a VSD has been successfully fixed with surgery, antibiotics should no longer be needed.
People with Eisenmenger’s complex, 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.
In some babies 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 usually must 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 canal 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 canal defect, before and after treatment, are at risk for 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.
Cyanotic defects
Another type of heart defect is congenital cyanotic heart defects. In these defects, blood pumped to the body contains less oxygen than normal. This causes a condition called cyanosis (si”ah-NO’sis), a blue discoloration of the skin. Infants with cyanosis are often called “blue babies.”
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.
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. They may even become unconscious. 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.
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 done 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 they are 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.
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 the 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 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.
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.
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 complete repair depends on the size of the pulmonary artery and right ventricle. If they’re very small, it may not be possible to correct the defect with surgery. In cases where the pulmonary artery and right ventricle are a 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, the surgeon can compensate by connecting 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 tricuspid atresia require lifelong follow-up by a 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.
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.
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. 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 sure that any remaining problems, such as an obstruction in the pulmonary veins or irregularities in heart rhythm, are treated properly. It’s 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 left side of the heart is underdeveloped – including the aorta, aortic valve, left ventricle and mitral valve. 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.
The baby often seems normal at birth, but will come to medical attention within a few days 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.
This defect isn’t correctable, but some babies can be treated with a series of operations or with a heart transplant. 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 choose surgery, it will be done 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 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.
Some doctors will recommend a heart transplant to treat this problem. Although it provides the infant with a heart that has normal structure, the infant will require lifelong medications to prevent rejection. Many other problems related to transplants can develop. You should discuss these with your doctor.
Children with hypoplastic left heart syndrome require lifelong follow-up by a 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 inner lining or 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.
HOW ARE CONGENITAL DEFECTS / BLUE BABY SYNDROME DIAGNOSED?
If an infant exhibits cyanosis, physicians will order many tests to determine the cause of the condition. Theses tests will vary according to the type, nature and severity of symptoms. Some of these tests wll be:
This test could be fetal (performed during pregnancy) and during infancy. Fetal echocardiography (e.g., ultrasounds) is a routine test and can help diagnose potentially cyanotic heart conditions before birth. This important advance allows both physicians and parents to plan for treatment immediately after the birth. Some congenital heart defects are and should be treated as soon as possible, instead of waiting for the child to grow.
WHAT ARE THE TREATMENT OPTIONS FOR CONGENITAL HEART DISEASE?
Diagnosing congenital disease at an early stage itself can be helpful. In many cases, the blue baby syndrome may be apparent shortly after birth but the condition may not become apparent until later. Because this is often the result of an underlying and serious heart defect, newborns who exhibit the cyanosis must be taken to an appropriate pediatric cardiac facility as quickly as possible. There, physicians will attempt to diagnose the defect and develop a plan of action.
The treatment could vary as per the magnitude of the disease. It could be:
Medications may be used to ease the symptoms of by reducing the workload of the muscles, vessels or chambers of the heart.
If medications are not helpful, then a more invasive treatment option may be advised. During this procedure, the physician can employ various strategies to improve valve, vessel and chamber problems.
Surgery may be undertaken during pregnancy itself or soon after birth. These surgeries include:
Many of these patients, both before and after surgery, are at risk of developing an inflammation or infection of the lining of the heart. Patients should discuss with their physician ways to avoid this.
While the long-term prognosis depends on the nature and severity of the specific condition(s) and on the appropriate treatment options, chances are better than ever before that properly treated blue babies will grow up to live happy, healthy lives