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CONGENITAL HEART DISEASE

What is Congenital Heart Disease ?

During a baby s development in the womb, the structure and connections of any organ may go wrong. The result of this is called a congenital defect. In the heart, the common defects include holes in the heart and narrow heart valves. There may also be plumbing abnormalities. For example, arteries and veins can be wrongly connected to the heart chambers. There may be no symptoms at first but the problem often gets picked up on a medical check after birth or at school. Some serious heart defects can even be picked up by ultrasound scans whilst the baby is in the mother's womb. Congenital heart defects may cause poor feeding, lack of weight gain, or a blue complexion in a baby. Later on there may be breathlessness or squatting; children squat on their haunches to relieve their breathlessness or blueness. Severe defects are fatal. Narrow heart valves cause a strain on the heart` s pumping. Holes cause blood to flow in the wrong direction. This is because the heart consists of two pumps side by side, but combined in a single organ. They are called the left heart and the right heart. The right heart only pumps blood to the lungs. The left heart pumps to all the rest of the body. It therefore pumps at a higher pressure. If there is a hole between the two sides, the higher pressure on the left forces blood across to the right. There is a similar condition where a blood vessel (a ductus) connects the two main arteries carrying blood out of the heart. These abnormalities cause a big blood flow through the lungs. The heart has to work harder to cope. This eventually causes symptoms of heart failure, especially breathlessness when the child exercises. If the blood flow in the lungs is too high they are damaged. The blood pressure in the lungs rises. This forces blood, which was flowing from the left heart to the right to change its direction and flow from right to left. The blood in the right heart, which is blue because it is low in oxygen, is then pumped straight into the rest of the body. This causes a blue complexion (cyanosis). This type of blood flow problem also happens with the more complicated “plumbing” defects, commonly referred to as complex congenital heart disease.

Why does Congenital Heart Disease occur ?

About 1 in 100 babies are born with congenital heart defects. We do not know why most congenital heart defects happen. Occasionally they are inherited. Sometimes during the earliest stage of pregnancy, a virus, such as German measles, damages the baby The defects are more likely in the offspring of women who have diabetes which is not well controlled. Excessive x?rays or exposure to drugs are other rare causes. Commonly used drugs are safe but it is impossible to test new ones. It is, therefore, best to avoid any drug in pregnancy, especially in the early months, unless it is considered essential by the doctor.

Treatment Involved for Congenital Heart Disease

DIAGNOSIS

Chest x-rays and electrocardiograms (ECGs) are useful, but echocardiography is the best test for assisting with diagnosis. This uses high frequency sound (ultrasound) from a microphone-like instrument, called a transducer. It is placed on the child's chest. There is no discomfort. The sound is reflected from the heart, back to the transducer where it is converted into electrical impulses which are displayed on a TV screen. A similar method, called Doppler, measures blood flows in the heart. It is a good way of finding holes and measuring any valve narrowing. Under sedation, an ultrasound probe can be passed down the gullet (oesophagus) to provide very accurate close-up pictures from the back of the heart. This is particularly useful with complex congenital heart defects. Magnetic resonance imaging (MRI) is another modern way of assisting diagnosis. If the diagnosis is still in doubt or if the defect is complicated, cardiac catheterization may be needed. It is often required before heart surgery This involves threading a small tube, called a catheter, into the heart from a blood vessel in the groin. Blood pressures are measured in the different heart chambers and blood samples are taken to measure their oxygen content. x-ray filming during injection of x-ray opaque fluid, produces moving pictures of the heart's structure.

TREATMENT

Minor faults, such as small holes or minor valve narrowing, may not require treatment. Some holes even close up of their own accord. If they are more severe they may cause heart failure. This leads to fluid retention, which produces swelling of the legs and breathlessness. A common treatment uses drugs called diuretics to get rid of the excess fluid that the kidneys retain and cause more urine to be passed. Many holes in the heart can be closed without cardiac surgery by cardiac catheterisation. Fine tubes and wires can be passed into the heart from the blood vessels in the groin. Small plugs can be passed over the wires and positioned permanently across a hole. This technique can also be used to close a ductus. In some instances cardiac surgery may be needed to close holes as well to open narrowed valves. This surgery is now commonplace; it has a low risk and a high success rate. Closing the holes usually cures the problem permanently Surgery can also deal with more complicated defects. Some cannot be corrected completely but there are ingenious operations to overcome their effects. More than one operation maybe needed. The first is carried out when the child is young and a more complicated operation is done when the child is bigger. Heart transplantation may be considered when the defect cannot be corrected. If the lungs have been damaged, heart and lung transplantation is a possibility in older children.

After Treatment for Congenital Heart Disease

Children or young adults with congenital heart disease should have frequent check-ups. This ensures that any worsening of the condition is picked up sooner rather than later. The doctor needs to be told if there is any increase in symptoms. Germs can get into the bloodstream, for example through the gums after dental treatment or after other operations which use instruments passed into the body There is then a risk of infecting any abnormal heart valves or other abnormal structures. This is called infective endocarditis. Antibiotics given, usually by mouth, an hour before dentistry or an operation will prevent this condition. Prevention is much better than cure. Many children who had operations when they were small are now adults. This has led to a new branch of cardiology called Grown Up Congenital Hearts (GUCH).

If Congenital Heart Disease is Left Untreated

Mild defects may not cause problems. Defects which increase blood flow through the lungs may damage them permanently This can sometimes happen early in life, so treatment should be carried out quickly Early surgery may sometimes prevent other problems later.

Effects on Family of Congenital Heart Disease

The presence of heart disease in children invariably places a strain on parents. Simple defects can be cured completely, however. Even complicated ones are amenable to surgery allowing a normal life in spite of a need for regular check-ups. There is a slightly greater risk of defects in subsequent children: ultrasound scanning in the next pregnancy may be very worthwhile.