Congenital Heart Disease

Congenital heart disease is defined as a heart problem that occurs as the baby's heart is developing during pregnancy, before the baby is born. In fact, congenital heart defects are the most common birth defects. The incidence accounts approximately for 0.8 – 1% of newborns. It is commonly found in female children, rather than male ones with the ratio 3:1.

In general condition, a baby's heart starts to develop at conception. During the first six weeks of pregnancy, the heart begins taking shape and starts beating. The major blood vessels also begin to form during this critical time. The heart development is completely formed by 8 weeks into the pregnancy. Congenital heart defects happen during this important first 8 weeks of the baby's development. Specific steps must take place for the heart to form correctly. Often, congenital heart defects are a result of one of these steps not happening at the right time.

Babies diagnosed with congenital heart disease can be categorized into 2 groups:
 

• Babies with cyanosis (cyanotic heart disease): A child’s heart defect causes oxygen-poor blood to mix with oxygen-rich blood in his or her heart, clinical manifestation includes a grayish-blue or purple color of skin and mucous membranes, a condition called cyanosis. Main treatment for this condition is surgery. However,  fatal complications might include poor development, impaired heart and lung functions due to insufficient oxygen level in the blood, abnormal heart rhythms and sudden death. If left untreated, the chances for babies to grow up is limited.
• Babies without cyanosis: The abnormalities can be formed in the heart valves (fairly rare) or in the septum of the heart’s chambers which is a common congenital defect. Holes can form in the walls between heart chambers or between major blood vessels leaving the heart. These holes allow oxygen-poor blood to mix with oxygen-rich blood. It results in less oxygen being carried to child's body. Severity depends on the size of the hole. Insufficient oxygen level can cause child's skin or fingernails to appear blue. If the defect is large, the extra blood volume (mixtures of oxygenated and deoxygenated blood) can overfill the lungs and overwork the right side of the heart. If left treated, it might eventually impair heart and lung functions in the future. These congenital heart defects can be categorized into several conditions such as:

• Ventricular septal defect (VSD): A hole in the wall between the right and left chambers on the lower half of the heart (ventricles).
• Atrial septal defect (ASD): A hole in the wall between the right and left chambers on the upper half of the heart (atria).
• Patent ductus arteriosus (PDA) : A connection between the pulmonary artery (containing deoxygenated blood) and the aorta (containing oxygenated blood). A complete atrioventricular canal defect is a condition that causes a hole in the center of the heart.

Signs and symptoms of congenital heart disease

Serious congenital heart disease usually becomes clearly evident soon after birth. Signs and symptoms include:
 

• Shortness of breath during feedings, leading to impaired development
• Pale gray, purple or blue skin color and fingernails (cyanosis)
• Rapid breathing

However, child may not have any noticeable signs of a problem until reaching the age of 20-30. Symptoms that might indicate heart disease may involve shortness of breath during exercise and easily tiring or fainting during activity.

Treatment of congenital heart disease

Certain congenital heart defects, such as small holes, may correct themselves as the child grows. However, some heart defects are serious and treatment is  highly required. Depending on the type and severity of heart defect, congenital heart defects can be treated with:

Procedures using catheterization. Some children and adults might have their congenital heart defects repaired using catheterization techniques. This less invasive procedure allows the repair to be done without surgically opening the chest and heart. Catheter procedures can often be used to fix holes or areas of narrowing. During performing procedures, a thin tube (catheter) is inserted into a leg vein and guides it to the heart with the assistance of X-ray images. Once the catheter is positioned at the site of the defect, tiny tools such as a mesh patch or plug is threaded through the catheter to close the hole or to repair the defects. The heart tissue grows around the mesh, permanently sealing the hole within 3 months.

This procedure can be performed in children aged over 5 and adults. However, antiplatelet drug, aspirin will be prescribed for at least 6 months in order to provide platelet anti-aggregation effect and prevent thrombus formation in the treated areas. After receiving treatment, close follow-ups with echocardiogram are required as scheduled, every 1, 3, 6 months and 1 year. More importantly, all medical advices given by cardiologists must be strictly followed.

Although catheterization can be used to treat congenital heart defects up to 75%, this procedure might not be suitable for some complicated conditions. These conditions may require heart surgery as a first-line treatment. Selected treatment option is primarily determined by size, location and type of the defects as well as individual’s conditions.

Advantages of using catheterization
 

1. Reduced chances to have open-heart surgery
2. No open cut in the chest is needed. Smaller incisions result in less pain.
3. Shorter hospital stay. It takes averagely 2-3 days, compared to 6-8 days required for heart surgery.
4. In adult patients, they can be self-dependent and get back to daily life quicker.
5. Faster recovery time at home. Only 2-3 days are required while open surgery needs 3-4 weeks for a full recovery.