Congenital Heart Disease 

 

What is congenital heart disease?

Congenital heart disease is the most common of all major birth defects. A congenital heart defect occurs when the heart or blood vessels near the heart do not develop normally before birth. These defects can involve:

·         A hole in the heart (Septal Defect)

·         Narrowed Valves

·         Defects that affect blood flow to or from the heart (i.e., tetralogy of Fallot)

·         Defects that affect the heart muscle, such as in cardiomyopathy

Congenital means inborn or existing at birth. Other names for congenital heart disease are congenital heart defect and congenital cardiovascular disease.

Types of Congenital Heart Defects:

There are many types of congenital heart defects. Some are simple, such as a hole in the wall (septum) that separates the right side of the heart from the left side of the heart. Other defects involve a narrowed heart valve that blocks blood flow to the lungs or other parts of the body.

A Hole in the Heart (Septal Defect):

The septum is the wall that separates the heart into left and rights sides. The wall prevents mixing of blood between the two sides of the heart. Sometimes, a baby is born with a hole in the septum. The hole allows blood to mix between the two sides of the heart.

Atrial septal defect (ASD): 

1. An ASD is a hole in the part of the septum that separates the atria—the upper chambers of the heart. 
2. This heart defect allows oxygen-rich blood from the left atrium to flow across into the right atrium instead of flowing down to the left ventricle as it should. 
3. Many children who have ASDs have few, if any, symptoms.
4. An ASD can be small or large. Small ASDs allow only a little blood to leak from one atrium to the other. 
5. Very small ASDs don't affect the way the heart works and don't require any treatment. Many small ASDs close on their own as the heart grows during childhood.

 

Ventricular septal defect (VSD): 

A VSD is a hole in the part of the septum that separates the ventricles—the lower chambers of the heart. The hole allows oxygen-rich blood to flow from the left ventricle over into the right ventricle instead of flowing into the aorta and out to the body as it should.

• A small VSD doesn't cause problems and may close on its own. 
• Large VSDs cause the left side of the heart to work too hard. 
• This increases blood pressure in the right side of the heart and the lungs because of the extra blood flow. The increased work of the heart can cause poor growth and heart failure. Open-heart surgery is used to repair VSDs.

Narrowed Valves:

Simple congenital heart defects also can involve the heart's valves. These valves control the flow of blood from the atria to the ventricles and from the ventricles into the two large arteries connected to the heart (the aorta and the pulmonary artery). Valves can have the following types of defects:

·         Stenosis (ste-NO-sis). This is when the valve does not open completely, and the heart has to work harder to pump the blood through the valve.

·         Atresia (a-TRE-ze-AH). This is when the valve does not form correctly, so there is no opening for blood to pass.

·         Regurgitation (re-GUR-ji-TA-shun). This is when the valve does not close completely, so blood leaks back through the valve.

The most common valve defect is called pulmonary valve stenosis, which is a narrowing of the pulmonary valve. This valve allows blood to flow from the right ventricle into the pulmonary arteries and out to the lungs to pick up oxygen. Pulmonary valve stenosis can range from mild to severe. Most children with this defect have no signs or symptoms other than a heart murmur. Treatment isn’t needed if the stenosis is mild.

Defects that Affect Blood Flow to and From the Heart:

The most common complex heart defect is tetralogy of Fallot (teh-TRAL-o-je of fah-LO), a combination of four defects:

·         Pulmonary valve stenosis.

·         A large Ventricular Septal Defect (VSD).

·         An overriding aorta. In this defect, the aorta sits above both the left and right ventricles over the VSD, rather than just over the left ventricle. As a result, oxygen-poor blood from the right ventricle can flow directly into the aorta instead of into the pulmonary artery to the lungs.

·         Right ventricular hypertrophy. In this defect, the muscle of the right ventricle is thicker than usual because of having to work harder than normal.

Together, these four defects mean that not enough blood is able to reach the lungs to get oxygen, and oxygen-poor blood flows out to the body.

Complex congenital heart defects need to be repaired with surgery.

  

Causes and Risk Factors:

What are the causes and risk factors of congenital heart disease?

According to the March of Dimes, in most cases scientists do not know what causes hearts to be developed abnormally.2 It does appear that genetics and the environment play a role, but exactly how is uncertain.

·         Genetics: Some heart defects have a clear genetic link, such as Long QT Syndrome. Since the 1990s, nearly 10 gene mutations (changes) that can cause isolated heart defects have been identified.

·         Viral: One particular virus, rubella (German measles), can cause heart defects if a woman contracts the disease the first three months of a pregnancy.

·         Heredity: For example, a parent who has a congenital heart defect may be more likely than other people to have a child with the condition. In rare cases, more than one child in a family is born with a heart defect.

·         Chronic illness: Certain chronic illnesses in the mother, such as diabetes, may contribute to heart defects.However, women with diabetes can reduce their risk by making sure their blood sugar levels are well controlled before becoming pregnant.

Symptoms:

What are the symptoms of congenital heart disease?

• Some heart defects do have signs and symptoms. They depend on the number, type, and severity of the defects. 
• Severe defects can cause signs and symptoms, usually in newborns.

These signs and symptoms may include:

·         Rapid breathing

·         Cyanosis (a bluish tint to the skin, lips, and fingernails)

·         Fatigue (tiredness)

·         Poor blood circulation

Congenital heart defects don't cause chest pain or other painful symptoms.

Heart defects can cause abnormal blood flow through the heart that will make a certain sound called a heart murmur. 

Older children who have congenital heart defects may get tired easily or short of breath during physical activity.

Many types of congenital heart defects cause the heart to work harder than it should. In severe defects, this can lead to heart failure. Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs.

Symptoms of heart failure include:

·         Fatigue with physical activity 

·         Shortness of breath 

·         A buildup of blood and fluid in the lungs

·         A buildup of fluid in the feet, ankles, and legs

  

Diagnosis:

How is congenital heart disease diagnosed?

Babies and children who are suspected of having a heart defect are usually referred to a pediatric cardiologist (children’s heart disease specialist). This doctor can do a physical examination and often recommends one or more of the following tests:

·         Chest X-ray 

·         Electrocardiogram, a test that records heart rate patterns 

·         Echocardiogram, a special form of ultrasound that uses sound waves to take pictures of the heart.

• All of these tests are painless and noninvasive (nothing enters the child’s body).
• Some children with heart disease also may need to undergo a procedure called cardiac catheterization. 
• In this procedure, a thin, flexible tube is inserted into the heart after the child is given medications to make him sleepy. This test provides detailed information about the heart and how it is working. 

Treatment:

How is congenital heart disease treated?

• Although many children who have congenital heart defects do not need treatment, some do.
• Cardiac surgeons are heart doctors who treat heart defects. These doctors repair heart defects using surgery.
• The treatment your child receives depends on the type and severity of his or her heart defect. 
• Other factors include your child's age, size, and general health.
•  Some children who have complex congenital heart defects may need several catheter or surgical procedures over a period of years, or they may need to take medicines for years.
• The doctor may perform a catheter procedure to close a hole in the heart and repair a valve. 
• Catheters are thin flexible tubes that are inserted into a vein to access the heart.

·         For a septal defect, the doctor inserts a catheter through a vein and threads it into the heart to the septum. The catheter has a tiny, umbrella-like device, or patch, folded up inside it. When the catheter reaches the septum, the device is pushed out of the catheter. It's positioned so that it plugs the hole between the atria. The device is secured in place and the catheter is then withdrawn from the body.

·         For pulmonary valve stenosis, the doctor inserts a catheter through a vein and threads it into the heart to the pulmonary valve. A tiny balloon at the end of the catheter is quickly inflated to push apart the leaflets, or "doors," of the valve. The balloon is then deflated and the catheter and balloon are withdrawn. This procedure can be used to repair any narrowed valve in the heart.

A child may need open-heart surgery if his or her heart defect can't be fixed using a catheter procedure. Sometimes, one surgery can repair the defect completely. If that's not possible, the child may need more surgeries over months or years to fix the problem. Open-heart surgery may be done to:

·         Close holes in the heart with stitches or with a patch

·         Repair or replace heart valves
Widen arteries or openings to heart valves

·         Repair complex defects, such as problems with where the blood vessels near the heart are located or how they developed

Living with Congenital Heart Disease:

What is it like to have a congenital heart disease?

• The outlook for a child who has a congenital heart defect is much better today than in the past. 
• Advances in testing and treatment mean that most children who have heart defects survive to adulthood and are able to live active, productive lives.
• Many of these children need only occasional checkups with a cardiologist (heart specialist) as they grow up and go through adult life.
• Children who have complex heart defects need long-term, special care by trained specialists.
•  This will help them stay as healthy as possible and maintain a good quality of life.