Congenital Heart Disease |
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Congenital Heart Disease Sometimes babies are born with abnormalities in the structure of their hearts, and this is the reason for careful examination of children after birth and in their early years, including routine medical examinations It school. Many of these abnormalities (given the 'umbrella' term of congenital heart disease) can be most easily treated in childhood. The causes are usually unknown although occasionally drugs, such as thalidomide, and infections, such as German measles (rubella), require special precautions when pim9nancy is suspected or diagnosed.The most common abnormality is a minor one of the aortic valve which, although usually not a problem in early years, may become so later. A similar abnormality may occur with the pulmonary valve. Next in frequency are abnormalities which connect the left and right hearts. As already described, the two sides of the heart are separate pumps and there is normally no communication between them. Because the blood pressure on the Is higher, any communication leads to abnormal flow of blood from the left to the right through this 'hole in the heart', through the lungs back to the left heart. As a result more blood flows through the lungs than through the rest of the body (normally the flows are identical) and, if the blood flow becomes very high and is uncorrected, it may cause lung damage which becomes permanent and cannot be treated. Therefore early diagnosis may be vital. The structure which separates the two hearts is called the septum defects may occur between the atria (atrial defect), between the ventricles (ventricular defect) or between the arteries which carry to the lungs and body respectively (ductus arteriousus). Surgery can close the defects and, unlike most other forms of cardiac surgery, it generally cures the disease rather than just relieving it. More complex congenital abnormalities also happen, for example, a combination of ventricular septal defect and a narrowing — stenosis — of the pulmonary valve, which leads to too little flow through the lungs, or transposition when the pulmonary artery and the aorta are attached to the wrong ventricles. Both of these conditions cause venous (blue, oxygen-poor) blood to be channelled directly into the oxygenated arterial supply to the body, giving the appearance of cyanosis (blueness) of-the skin. These defects can be dealt with either by surgical correction of the heart itself or by surgery which relieves the effects of the abnormality without totally correcting it. Heart surgery for these types of defects is less easy. Success is related to the skill of the surgeon and to the severity of the abnormality. |
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