Atresia of the pulmonary artery in newborns is a dangerous congenital disease characterized by the fact that there is no direct communication between the right ventricle of the heart and the pulmonary arterial channel.
As a result, pulmonary circulation is sharply reduced or absent altogether, the blood ceases to be saturated with oxygen, and the patient dies within a few days of increasing hypoxemia.
Fortunately, this disease is rare: in 1-3% of all births with congenital heart disease, or CHD.In turn, the frequency of birth of children with CHD is also relatively small: about 6-8 cases per 1000 births.
Causes of the disease and risk factors
Causes of the disease have not yet been clarified, however, it is known, that, as with other types of AMS, the cause is the
point gene change ( mutation), which can occur both spontaneously and under the action of mutagens. 
Today, has two basic theories of the development of heart defects : according to the first, put forward by Rokitansky in 1875, the UPU is explained by the arrest of the development of the heart at a certain stage of the individual development of the body.
Spitzer's theory( 1923) speaks of a return to a certain stage of evolutionary development, or phylogenesis.
The risk factors are the presence of mutagen in the environment: physical( ionizing radiation), chemical( phenols, which are contained in dyes, lithium compounds, antibiotics during pregnancy, etc.), biological( rubella, diabetes mellitus, maternal alcoholism).
Forms and species
J. Somerville( J. Somerville) in 1970, a classification was adopted, based on the degree of preservation of pulmonary arteries. According to this classification, 4 types of defect are identified:
- pulmonary atresia( there is a pulmonary trunk and both arteries);
- atresia of the valve of the pulmonary artery and its trunk( there are only arteries);
- atresia of the pulmonary valve, trunk and one pulmonary artery( the only pulmonary artery remains);
- atresia of the pulmonary valve, trunk and both pulmonary arteries( blood circulation in the lungs occurs due to collateral systemic arteries).
Very often there is atresia of the pulmonary artery with an interventricular septal defect in children( see the illustration on the right).
Danger and complications
The disease develops rapidly and the presents a serious danger to the life of the child in the first weeks and even days of his life.
The arterial, or bone, duct that connects the pulmonary trunk to the dorsal aorta in the fetus and the newborn helps maintain blood flow in the lungs in the early days of life.
But soon it overgrows, and then blood circulation in the lungs stops , death from oxygen starvation occurs.
Mortality is also associated with progressive narrowing of the aorto-pulmonary collateral arteries.
Complications include postoperative heart failure caused by elevated blood pressure in the right ventricle and respiratory failure caused by surgeon's errors during dressing of the large aorto-pulmonary collateral artery.
Symptoms of
For atresia of the pulmonary artery, symptoms of hypoxemia ( oxygen starvation) are characteristic. This, above all, a common cyanosis, that is, blue, which is preserved from the birth of the child.
Unlike other CHDs, has no cyanotic attacks there is no .But there are bulbous thickenings on the terminal phalanges of the fingers( the so-called "drum sticks", and the deformation of the nail plates( "watch glass" and "Hippocrates nail.")
The thorax on the left side is deformed, protruding forward( " heart hump "), Electrocardiogram changes are not characteristic, the electric axis of the heart can be deflected to the right.
The child may experience rapid breathing, rapid fatigue, sweating during feeding. The skin can be pale, with a greyish tinge, sticky and cold
Auscultation( listening) shows the accent of the 2nd tone in the heart base region, the noise in the third intercostal space of the , which is carried on the back
The x-ray differs from the norm : the contour of the lungs is weaker, the roots are poorly delineated. Sometimes asymmetry of the pattern occurs( one lung is seen more clearly than the other.) The heart shadow can be of normal size, or slightly enlarged in diameter. The upper part of the heart is elevated by the enlarged right ventricle, the shadow of the ascending aorta is enlarged.
The angiocardiographic study of begins with the introduction of a contrast medium in the right ventricle and is the only way to identify sources of supply of blood in the lungs. Therefore, the procedure is given great importance in the preparation for the operation.
When to call a doctor
Because the disease is deadly, and the course is swift, then you should see a doctor immediately, as soon as there are suspicions.
Atresia of the pulmonary artery is often diagnosed in the maternity ward , after which the newborn undergoes the necessary studies and is sent for surgery. If symptoms of the disease appear outside the medical facility, you should immediately consult a doctor.
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Diagnosis
Initially, the disease is diagnosed by according to the appearance of ( See "Symptoms of the disease").To confirm the diagnosis, fluoroscopic examination is performed, and then, if the diagnosis is confirmed - catheterization and angiocardiography. The latter allows you to determine which type of disease you have to deal with.
If these methods fail to contrast the true pulmonary arteries, the contrast agent is injected into the pulmonary vein against the blood flow.
Catheterization is carried out in the same way as in patients with tetralogy of Fallot.
Treatment
Surgical intervention is the only current treatment. Operations for this type of UPU are of two types: radical and palliative .
The first allows completely to eliminate the cause of the disease and is performed in cases when the patient has pulmonary arteries of normal size( type I disease).In type II and III, a radical operation is also possible, but requires an artificial trunk and valves of the pulmonary artery.
Immediately after the operation is performed a secondary angiocardiographic examination of the to make sure that the intervention was successful and all the lung units are washed with blood. If not, the patient is returned to the operating table.
After 5-10 years of after palliative surgery, angiocardiographic examination is performed again. If during the elapsed time the normal development of pulmonary arteries began, then a radical operation is performed.
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Prognosis and prevention measures
With timely treatment, the prognosis is favorable to .Among patients who did not require stitches of the artery and valve stem, postoperative mortality reaches 6.2%, but sharply increases among patients who need stitching( 23%).
Usually patients after the operation feel good, the main cause of death is heart failure, associated with increased blood pressure in the right ventricle.
In the absence of treatment, the patient dies from the oxygen starvation of in the first weeks of life of , however, there have been cases when patients with large aortolateral collateral arteries have maintained viability for a long time.
Prevention measures are typical for all diseases caused by mutations:
- to avoid exposure to physical and chemical mutagens;
- do not consume alcohol and antibiotics during pregnancy;
- to avoid pregnancy during a rubella disease;
- if the UPU has already met in the family of the mother or father, or if one of the children from this marriage already has the disease, it is necessary to contact a genetic counselor.
Thus, atresia of the pulmonary artery is a congenital heart disease caused by a lethal or sublethal gene mutation. A mutation can occur spontaneously with or be induced by exposure to environmental factors( mutagens), and is inherited.
To date, is only treated surgically by , the prognosis depends on the type of disease that varies in severity.
