What causes congenital heart disease in children

Congenital heart disease occurs in a child during fetal development. On average, 1% (0.8-1.2%) of all newborns are diagnosed with cardiac anomalies. In the group of all congenital pathologies, they account for up to 30%. They are associated with heart valves, septa, or arteries. More often than other heart defects in newborns, ventricular septal defects are noted (31% of all cases). Less common is narrowing of the aortic valve.

What is heart disease, classification of pathology

This is a disease characterized by a violation of the anatomy of the heart or its elements: valves, vessels, chambers. It occurs in the fetus during the period of its bearing by a woman. Any defect disrupts hemodynamics in the child's body, which, in turn, is harmful to health and threatens life.

• the heart has insufficient performance;
• the load on him increases;
• blood flow changes both throughout the body and in the heart muscle.

Often, cardiac anomalies are associated with other congenital problems. For example, in the central nervous system, musculoskeletal system, gastrointestinal tract.

Photo: examples of congenital heart anomalies

There are seven types of defects in total.

1. Septal defect between the atria (7% of cases). Normally, at birth, this septum closes, but sometimes it fails. In connection with this, increased pressure occurs and blood circulation changes (it immediately enters the left and right atria). The opening is necessary for the fetus due to the fact that the lungs are not yet functioning. But when the baby is born, the need for a detour disappears. As a rule, this defect disappears during the first months of life. If not, then problems begin.
2. Septal defect between the ventricles (31% of cases). As in the first case, blood is thrown, but not from the atria, but from one ventricle to another. Because of this, there is shortness of breath and lack of oxygen (feeling of asphyxia). The severity of symptoms depends on the size of the "window" between the ventricles. Septal defects (atrial and ventricular) can be suspected by blue skin tone, weak physical strength, and fatigue. Treated surgically. A small defect can go unnoticed for a long time and be found by accident.
3. Mutual substitution (transposition) of the location of the aorta and pulmonary artery (5% of cases). As a result of this, a powerful oxygen starvation occurs and death occurs in a short time. This pathology is incompatible with life. The only way to save a baby is through emergency surgery.
4. Narrowing of the pulmonary or aortic valve (3-7% of cases). Causes circulatory disorders, oxygen deficiency, high blood pressure. The heart has to work harder.
5. Fallot complex (up to 5% of cases). This is the name of a whole complex of defects: an open interventricular septum, displacement of the aortic orifice, narrowing of the pulmonary valve, an increase in the right ventricle.

Not always defects are diagnosed immediately after birth. The smaller the defect, the later its consequences may become noticeable. Particularly severe defects, on the contrary, are detected even during pregnancy (anomalies of the pulmonary artery and pulmonary valve).

The presented classification is not the only one.

Anomalies can also be differentiated by the effect they have on hemodynamics in the body:

1. Unchanged or slightly changed blood flow in a small circle. This group includes overgrowth of the aortic valve, narrowing of the aorta, weakness of the pulmonary valve, excess atrium.
2. Increased blood flow. This category includes open duct, septal defects, aortic-lung junction, Lutambacher's syndrome. These anomalies do not cause blue integumentary and mucous tissues. Under the same type, according to the classification under consideration, a number of anomalies fit more: overgrowth of the tricuspid valve with a ventricular septal defect, an open duct with increased pulmonary pressure. These problems cause the skin and mucous membranes to turn blue.
3. Reduced blood flow. This description fits the narrowing of the pulmonary artery, which does not cause cyanosis. As well as the complex of Fallot and Ebstein, an increase in the ventricle. These defects provoke bluing.
4. Violation of blood flow in a small and large circle. This group includes serious anomalies such as mutual substitution of the main vessels, attachment to one trunk.

Given the characteristic ability of defects to affect skin color and practical ways to solve anomalies, experts have identified another classification: “blue” anomalies with a veno-arterial shunt, “white” anomalies with arteriovenous shunt and anomalies with an obstruction to ventricular ejection. The first group includes the Fallot complex, the replaced position of the vessels, the overgrowth of the tricuspid valve. The second group includes septal defects, an open duct. And to the third category - narrowing of the aorta and arteries, overgrowth.

Particularly life-threatening is the overgrowth of the pulmonary artery. With such an anomaly, the blood is not filtered by the lungs at all, that is, it is not saturated with oxygen. It is dangerous failure of all body systems.

Causes of pathology

There are a great many negative factors that can cause the development of defects. Some of them are subjective, and some are objective for a woman who is carrying a fetus.

• bacterial and viral infections carried by the mother during pregnancy;
• taking medications during pregnancy (even improperly selected vitamins can have a detrimental effect on the fetus);
• smoking, drinking alcohol or drugs;
• harmful working conditions or pollution of the territory of residence;
• irradiation.

The rubella suffered by the mother during pregnancy has an extremely negative effect on the development of the fetus. In the child's body, several serious pathologies occur at once: deafness, cataracts, myocardial defects, microcephaly, lag in growth and development (mental, intellectual, physical). Smallpox, herpes, hepatitis, syphilis, tuberculosis and other diseases also pose a particular threat. Any disease, even a common cold, is dangerous for the fetus.

However, only 1 to 2% of anomalies depend on external factors. The greatest role is played by the combination of heredity and environmental conditions (90%). Violation in the chromosomes affects in 5% of cases. In second place is gene mutation (from 2 to 3%).

There is a dependence of the types of anomalies on the influencing factors:

1. With chromosomal quantitative or qualitative disorders, anomalies occur in the septa of the heart.
2. With gene mutations, heart defects are associated with diseases of other systems and are part of a syndrome, for example, Cruzon, Hurler.
3. With intoxication, for example, as a result of mother's alcoholism, "windows" appear in the partitions and the opening of the arterial duct.
4. The intake of amphetamines by a woman causes a rearrangement of the main vessels.
5. Anticonvulsant drugs entail narrowing of the aorta and pulmonary artery, opening of the duct, Fallot's complex, and enlargement of the left heart.
6. Against the background of the use of lithium preparations, a defect in the tricuspid valve develops.
7. Progestogens can cause a Fallot complex.

Additional negative factors include early (15-17 years) and late pregnancy (from 40 years), toxicosis in the first trimester, the threat of miscarriage, cases of stillbirth in the woman’s medical history, hormonal imbalance due to problems in the thyroid gland, recorded cases of congenital heart anomalies in family history.

Symptoms

As a rule, it is not necessary to wait for the onset of symptoms, because the baby's heart is regularly subjected to a medical examination. However, the defect does not always make itself felt immediately. The duration of "stagnation" is affected by the rate of functional separation of circulatory circles, the pressure in the lungs, the characteristics of blood flow, the body's ability to adapt and compensate for failures.

• blue lips, skin and nails (typical for pathologies with cyanosis), aggravated by the slightest exertion;
• blanching and glaciation of the extremities (typical for "white" anomalies);
• palpitations and uneven breathing;
• edema;
• murmurs in the heart;
• slow body growth;
• signs of heart and respiratory failure;
• anxiety;
• rapid fatigue;
• crying;
• refusal of food;
• sweating;
• swelling and pulsation of the cervical artery.

The first three months of pregnancy are fundamental. It is at this time that the influence of any possible negative factor can cause irreparable harm to the child. It is also worth noting that after birth, any infection that enters the body can aggravate the effect of anomalies on blood circulation.

How to determine

The age of one year is a “test” milestone for all children with anomalies in the development of the heart, which are characterized by a large emission of blood. At this time, it decreases, which means that the patient's condition improves. But without surgery, only half of all children survive to this point. And even if we are talking about independent “survival”, then despite the improvement in well-being and a decrease in emissions, the gradual development of atherosclerosis is diagnosed.

Against the background of "blue" anomalies in the body, as a rule, compensation occurs. Due to insufficient oxygen supply, a network of small capillaries expands through large vessels. But gradually the body's resources are depleted, the heart gets tired of constant maximum loads, and overall health begins to deteriorate rapidly. The heart undergoes irreversible deformation. In this case, surgery is also indispensable.

The risk of defects and life prognosis directly depend on both the complexity of the defect and the treatment, as well as the patient's lifestyle. If no measures are taken, then a person may not live even to middle age. Most of the defects can be detected during pregnancy. This is not a reason to terminate the pregnancy, but a reason to prescribe treatment and make a treatment plan in the future.

1. Examination of the baby and collection of anamnesis. First of all, skin color is evaluated. If blueing is observed, then its features are fixed, for example, the type of distribution (generalized or local).
2. Listening with a stethoscope. All anomalies cause a violation of blood flow, which is manifested by wheezing. By the nature of wheezing (noise), an experienced specialist will be able to voice a preliminary diagnosis. The examination is supported by phonocardiography. It more accurately shows the noise and the nature of the heart sounds.
3. An electrocardiogram (ECG) allows you to determine the anatomical features of the heart (the size of the chambers and the entire muscle, the location of the departments) and the specifics of its work (rhythm, conduction). To compile the most accurate picture, daily monitoring of the work of the heart is carried out.
4. Echocardiography, or ultrasound (ultrasound). Allows you to visually examine the heart, assess its size, structure, structure, location. Along with this, it is possible to trace the functionality of the muscle and the work of individual elements of the heart. This method of diagnosis is considered the main one. It is absolutely safe and well tolerated by children. Allows you to identify any defects.
5. X-ray shows the condition of the spine, lungs, the nature of blood circulation in a small circle.

What to do

Treatment is usually surgical. We can talk about minimally invasive or open manipulations. Their goal is to restore the normal functioning of the heart, to eliminate defects. In complex cases, sometimes it is necessary to carry out several operations in a row.

Heart surgery is undesirable for children under the age of one year. If the defect does not cause heart failure, and the cyanosis is moderate or not expressed, then surgical procedures may be delayed. The child at this time will be under the supervision of a cardiologist and a cardiac surgeon.

1. For septal defects, suturing or closure with a catheter is indicated.
2. With severe pulmonary insufficiency, anastomosis is indicated. And after the normalization of blood flow, the main operation is performed to remove the defect.
3. With aortic defects, plasty, resection, ligation of the duct are indicated.
4. The narrowing of the pulmonary artery lumen is corrected with an inflatable catheter.
5. Complex anomalies are treated by disconnecting the circulation circles. At the same time, the defect remains, but doctors find a way to bypass it, which allows improving the quality of life of the patient. Used, for example, the method of Fontaine, Senning, Mustard.
6. In especially severe cases, a heart transplant is prescribed.
7. Any treatment is supplemented with anti-symptomatic therapy.

The most difficult and dangerous is the operation to restore the anatomically correct positions of the pulmonary artery and aorta. It must be carried out in the first days of the baby's life, since at this time he has not yet switched to the adult respiratory system. During the operation, cardiac surgeons cut off the vessels, change their places and sew. If this is not done, then in a few days the child will die. In case of complicated anomalies, for example, those associated with other disorders, probing is indicated.

Forecast and prevention

Mortality from congenital anomalies of the heart muscle among newborns occupies a leading position. Without the help of doctors, about 25% of children live up to a year. With a successful compensatory function of the body - 5% more. However, despite such frightening figures, the overall forecast is not so sad. With early detection of the defect and correct timely treatment, you can save and significantly improve the life of the baby.

As part of prevention, women are advised to follow all the advice of a gynecologist, to avoid harmful factors.

• overwork;
• stress;
• toxins;
• bad ecology;
• trauma;
• surge;
• unhealthy food.

If pregnancy is planned in advance, then you need to carefully prepare for it, take into account all possible obstacles to the birth of a healthy baby. You must first undergo a complete examination, including medical genetics. Women at risk (diseases, aggravated heredity) are advised to attend explanatory consultations, at which a specialist will describe all the risks, possibilities for monitoring and preventing anomalies, cases of necessary termination of pregnancy.