This type of congenital heart disease is the most common and can be detected during pregnancy!

Author: Lv Zhenyu, deputy chief physician, Beijing Children's Hospital, Capital Medical University

Reviewer: Jin Mei, Chief Physician, Beijing Children's Hospital, Capital Medical University

Ventricular septal defect is the most common congenital heart disease.

Simple ventricular septal defect accounts for about 20% of congenital heart diseases. If ventricular septal defect is combined with other cardiac structural abnormalities, its proportion can exceed 50%.

A normal heart has four chambers, which are like four bedrooms, with two rooms upstairs and two rooms downstairs.

The two rooms upstairs are called the right atrium and the left atrium, and the two atria are separated by the atrial septum; the two rooms downstairs are called the right ventricle and the left ventricle, and the two ventricles are separated by the ventricular septum; the normal atria and ventricles are separated by the atrioventricular valve.

Figure 1 Original copyright image, no permission to reprint

The so-called ventricular septal defect means that the septum between the two ventricles is interrupted, forming an abnormal communication and causing a left-to-right shunt at the ventricular level. To use a vivid metaphor, it is like a wall between two rooms with a hole in the wall, which connects the two rooms. This is a congenital heart malformation.

There is currently no clear cause of ventricular septal defect, but there are some high-risk factors that can lead to ventricular septal defect, one is genetic factors, and the other is environmental and chemical factors.

Genetic factors mean that ventricular septal defect and other congenital heart diseases have obvious genetic tendencies and familial clustering phenomena. Especially in cases with multiple heart malformations, more attention should be paid to genetic problems and other family members should be checked.

Environmental and chemical factors. Usually the most critical time for heart development is the first 3 months of pregnancy, especially in the 8th week of pregnancy, which is the most important stage of ventricular septum or heart development. If disturbed by environmental or chemical factors at this time, it will cause various developmental abnormalities and heart malformations.

For example, the most common case is that pregnant women may have viral infections or use certain medications in the early stages of pregnancy; or they may be exposed to toxic and harmful substances such as gasoline, lead, benzene, formaldehyde, ionizing radiation, etc. in the work or living environment, all of which may cause ventricular septal defects and other congenital heart diseases.

Figure 2 Original copyright image, no permission to reprint

In general, large ventricular septal defects can be clearly detected through prenatal examinations. Fetal echocardiography can be performed at 18-22 weeks, which is the second trimester of pregnancy, but very small defects may not be detected.

So some people say that the examination results have been good all the time, but after the child is born, it is discovered that there is a 3 mm or 2 mm ventricular septal defect. This is entirely possible.

Because when the ventricular septal defect is very small, the shunt is not obvious and it is not easy to see on fetal echocardiography. In addition, fetal echocardiography is affected by many factors, such as different fetal positions and different sections of the heart probe, which may not be very accurate; for example, the amount of amniotic fluid can also affect the observation. Therefore, there are many influencing factors. Therefore, large ventricular septal defects can generally be found, and small ventricular septal defects may be missed during pregnancy.

Ventricular septal defect, including atrial septal defect, patent ductus arteriosus, and pulmonary valve stenosis, are common and simple congenital heart diseases with the best treatment effects, with a cure rate of nearly 100%.

Therefore, even if this type of disease is discovered, there is no need to be too nervous, because there are ways to treat it after birth, and the treatment technology is very mature and the treatment effect is very certain.

Figure 3 Original copyright image, no permission to reprint

Unless it is a very large ventricular septal defect, similar to single ventricle, it can be said that there is almost no wall between the two ventricles, which we call functional single ventricle. This situation is usually accompanied by other heart malformations, and the surgical effect is poor, so it needs to be carefully considered.

Therefore, if it is a simple ventricular septal defect, parents do not need to be overly nervous.