Congenital heart disease - Bệnh tim bẩm sinh là gì?

Congenital heart disease

Congenital heart disease (CHD) is heart disease in the newborn, and includes structural defects, congenital arrythmias, and cardiomyopathies. CHD is a defect of the heart that exists primarily at birth, and can describe a wide variety of different abnormalities affecting the heart. CHD occurs when the heart or blood vessels near the heart does not develop properly before birth. Therefore, the heart does not pump because it is not completely developed. Also the blood flow is obstructed in the heart of the vessels nearby, causing an abnormal flow of blood through the heart. Blood flow obstructions put a strain on the heart muscle causing the heart to work harder and beat faster. Abnormal blood flow usually occurs when there is a hole in the walls of the heart and may be an abnormal connection between two arteries outside the heart.

Antenatal Detection and Diagnosis

Before birth, an obstetric ultrasound scan may be used to screen pregnant women for signs of CHD in their unborn babies. This screening scan is often performed around 20 weeks of pregnancy when the fast moving structures of the fetal heart are large enough to be more easily imaged. If CHD is suspected, a mother will be referred for a fetal echocardiograph, which is a more detailed, diagnostic ultrasound scan by a specialist cardiologist. It is increasingly possible for specialists to screen for CHD as early as 14 weeks, if CHD is suspected from other factors, such as a family history.

Postnatal Detection and Diagnosis

After delivery, if congenital heart disease is present but has not been detected, then a newborn baby may appear blue or breathless. Signs of CHD are sometimes mistaken for an infection or illness, so it is important to rule this out. Blueness and/or breathlessness may take some time to present, depending on the type of congenital heart disease and whether there is a duct-dependent lesion (i.e. one relying on an open ductus arteriosis for blood flow). This duct usually closes within the first three days of life in babies born at term (i.e. at nine months gestation).

Detection and Diagnosis in Adulthood

Although the majority of congenital heart disease diagnoses are made in childhood, there are significant congenital heart defects which may be go undetected until adulthood. These typically include defects that do not cause cyanosis ("blueness") in childhood but may cause problems over time, such as certain kinds of valve problems, transposition disorders, holes in the heart, and abnormalities of the heart's major veins and arteries. Congenital heart defects are most commonly diagnosed through an echocardiogram - an ultrasound of the heart which shows the heart's structure. Cardiac magnetic resonance(MRI) are used to confirm CHD when signs or symptoms occur in the physical examination. An echocardiograph displays images of the might also be used to confirm the problem, particularly in complex defects in which anatomy is hard to determine with echocardiography. It also finds abnormal rhythms or defects of the heart present with CHD. A chest x-ray may also be issued to look at the anatomical position of the heart and lungs. A Cat Scan(CT) can also be used to visualize CHD. All of these tests are ways to diagnose CHD by a physician.

Outcomes

It is now estimated that the number of adults in the United States who have congenital heart disease is approaching one million. Because of advances in cardiac surgery, many who would not previously have survived childhood, now lead normal or relatively normal lives. However, some increase in complications has been observed in adults who were previously thought to have had successful repair of heart defects. These complications include cardiac arrhythmia, disorders of heart valves, and heart failure. Regular check-ups by cardiologists are now recommended for patients with histories of congenital heart disease, including those who may have previously been told that their defects were successfully repaired. Since most adult cardiologists have little experience with congenital heart disease, have been developed to care for adult patients with congenital heart disease. It is thought that some patients, especially those with more complex disorders, and women who are pregnant or considering pregnancy, would likely do better if they are followed in specialty centers. Guidelines have been developed regarding which patients may be successfully followed in non-specialized cardiology practices, and which should be seen in adult congenital heart disease centers