Ventricular septal defect in children is a congenital anomaly that occurs during the period of intrauterine development of organs, the heart in particular. This defect, along with other congenital heart defects, is the most common in medical practice. Statistics in numbers reaches 42% of all congenital heart defects. Moreover, the gender factor does not play any role: both boys and girls are equally often affected by the disease. However, a direct genetic relationship from the closest blood relatives has been proven. Doctor of Medical Sciences Yu. M. Belozerov in his work "Children's Cardiology" indicated that the probability of developing a defect in this case increases by 3.3%.
Congenital defect of the interventricular septum of the heart is characterized by a violation of blood flow through the large and / or small circles of blood circulation. Along with all existing malformations, heart disease is still the main and most common cause of early death in children.
For a better understanding of the essence and characteristics of this defect, it is necessary to go a little deeper into epidemiology.
Epidemiology
The interventricular septum is involved in the process of contraction and relaxation of the muscles of the heart. In the fetus, it is fully formed at 4-5 weeks of development. With any deviations in the development process, a defect remains in it, which subsequently disrupts hemodynamics and causes further he alth problems. In 80% of cases, the defect is found along the perimeter of the membranes. The remaining 20% have defects in muscle genesis.
Defect classification
Ventricular septal defect is a congenital heart defect. Typically, these defects are divided into large, small and medium. To estimate its size, they compare it with the diameter of the aorta. Defects ranging in size from 1 to 3 mm are small, they are located in the muscular wall of the interventricular septum, and are called Tolochinov-Roger disease. It is characterized by good visualization during diagnosis, as well as a minimum of hemodynamic abnormalities and, by and large, in itself does not pose a danger to the human body. In this case, the aforementioned defect can be detected during a random examination, this is a kind of physiological feature that may not manifest itself in any way throughout a person’s life, and all that may be required is only control in dynamics. Another thing is large multiple defects, 1 cm or more in size, with obvious vivid symptoms that threaten he alth and life. In this case, doctors strongly recommend that an operation be performed in the first 3 months of a child’s life in order tominimize possible complications and death.
Departments of the interventricular septum
The interventricular septum consists of three sections: the upper (its densest part) is membranous, adjacent to the connective tissue, the middle part covers the heart muscle, and the lower part is trabecular, forming a spongy structure.
Based on anatomical location, defects are classified as follows:
- perimembranous ventricular septal defect accounts for 75% of all defects, located in the upper part under the aortic valve; may spontaneously close;
- muscular septal defects - up to 10% of interventricular defects are located in muscle tissue, away from valves and conduction systems;
- supracrestal defects - make up the remaining 5%, are located above the supraventricular crest, and are unable to close spontaneously.
Hemodynamics
What happens to a baby born with a ventricular septal defect? How does the defect manifest itself?
Intracardiac disorders do not begin to form immediately from the moment of birth, but on the 3rd-5th day. In such an early period, heart murmurs may not be heard at all, due to the same pressure in the ventricles due to pulmonary hypertension. Later, when the pressure in the pulmonary artery gradually drops, there is a dissociation of pressure in the ventricles - this leads to the ejection of blood from an area of high pressure to an area of low pressure, from left to right. This leads to the fact that the right ventricle experiences a constantsupersaturation with blood, additional volume overwhelms the vessels of the pulmonary circulation - this is how pulmonary hypertension develops.
Stages of pulmonary hypertension
It is customary to distinguish the stages indicated by the Russian cardiac surgeon Burakovsky, a specialist in the field of congenital heart defects in young children.
- Hypervolemic stage. It all starts with blood stagnation and is aggravated by pulmonary edema, decreased immunity and, as a result, frequent infections, but most importantly, the development of pneumonia with a severe course and difficult to treat. In the absence of the body's response to conservative treatment, they resort to a surgical operation - narrowing of the pulmonary artery according to Muller. The operation allows you to artificially narrow the lumen of the artery, which for some time will provide a smaller release of blood into the pulmonary circulation. However, the effect of this method is not long-term, and after 3-6 months, a second operation is usually required.
- Over time, Kitaev's reflex is triggered in the vessels. The bottom line is that the vessels react to overload and stretching with spasms. And this is followed by an imaginary latent course of the disease, a transitional stage. At this time, the child can stop getting sick, he becomes active, gaining weight. This condition is the most favorable for the operation.
- High pulmonary hypertension - Eisenmenger's syndrome. In the long term (in the absence of surgery), vascular sclerosis develops. This is a very dangerous and irreversible process. At this stage, cardiac surgeons most often refuse to perform surgery on patients.intervention, due to the lack of reasonable guarantees for a cure and the severity of the patient's condition. When listening, the 2nd tone over the pulmonary artery is pronounced, the systolic murmur becomes weak or it is completely absent. The appearance of Graham-Still murmur, diastolic murmur due to valvular insufficiency is fixed. Characteristic signs are wheezing and hard breathing, the chest protrudes in the form of a dome and is called a "heart hump", cyanosis worsens - the skin and mucous membranes become cyanotic, and from the peripheral, cyanosis develops into diffuse.
Causes of ventricular septal defect
Let's turn to the causes of this defect.
Most often, a ventricular septal defect in children is formed at the stage of organ laying and is caused by intrauterine developmental disorders. This defect is often accompanied by other cardio disorders. In 25 to 50% of cases, the defect goes hand in hand with abnormal kidney development, mitral valve insufficiency, and Down's syndrome. A direct negative impact during the period of embryonic development is caused by endocrine disorders in the body of a pregnant woman, viral infections. The negative impact of the environment and poor ecology, exposure to radiation, the use of alcohol and drugs, as well as abortion and toxicosis can affect. Not the last role is played by hereditary factors. It should be noted that the main cause of the development of an acquired defect is complications aftermyocardial infarction.
Clinical picture
The clinical picture of ventricular septal defects consists of a whole range of symptoms characteristic of heart failure. As a rule, they develop by 1-3 months of a child's life. It all depends on the size of the above defect. The presence of a defect is indicated by the occurrence of early prolonged bronchitis and pneumonia. Upon closer examination, the child looks pale and lethargic, inactive, drooping, with a characteristic lack of vital interest in his eyes. Shortness of breath can be detected, which is noted both during physical activity and at rest, tachycardia, expansion of cardiac boundaries or their displacement. A symptom called "cat's purr" is also characteristic, congestive wheezing is heard. As a rule, the systolic murmur is very intense, passes to the right side of the sternum, is heard in the IV intercostal space to the left of the chest and from the back. There is a pathological increase in the size of the liver and spleen on palpation. In children, hypertrophy develops very quickly.
Diagnostic Methods
Standard diagnosis of any heart disease consists of a chest x-ray, ultrasound, ECG - electrocardiography, and two-dimensional Doppler echocardiography, MRI. X-ray examination gives a superficial description of the shape of the heart, determines the size of the cardiothoracic index.
ECG will show if there is an overload of the ventricles, and later the atria, the heart and hypertrophy - all of them are witnesses of highdegree of pulmonary hypertension.
What will the ultrasound show?
Ultrasound for ventricular septal defect in the fetus can detect many pathologies of the heart at the earliest stages of development, is a simple, widely accessible, and at the same time informative research method.
The study provides the following information about the heart:
- cell size, structure and integrity;
- the condition of the walls of the heart, the presence or absence of blood clots and neoplasms in them;
- amount of fluid in the pericardial sac;
- pericardial condition;
- wall thickness of heart chambers;
- state and diameter of coronary vessels;
- structure and function of valves;
- behavior of the myocardium at the time of contraction and relaxation;
- volume of blood during its movement through the heart;
- possible organ noises;
- presence of infectious lesions;
- partition defects.
Doppler echocardiography
With Doppler echocardiography, the exact location of the defect, its size, as well as pressure in the right ventricle of the heart and pulmonary artery are specified. For the first stage of pulmonary hypertension, indicators up to 30 mm Hg are characteristic, for the second - the indicators range from 30 to 70 mm Hg. Art. In the third - the pressure is above 70 mm.
Magnetic resonance imaging
MRI examination is the most informative and revealing method of examination. It visualizes the current state of tissues and blood vessels, helps to establishor clarify the diagnosis, suggest the subsequent development of the disease and develop an optimal and appropriate treatment plan. Timely diagnosis of a ventricular septal defect undeniably increases the chances of preventing the aggravation of the disease and speedy recovery of the patient.
Treatment
Treatment of heart disease in ventricular septal defect consists of conservative treatment and surgical intervention in the heart tissue. Conservative therapy includes drug therapy. As a rule, we are talking about inotropic drugs in combination with diuretics. In the case of surgical intervention, a palliative operation is performed - a narrowing of the lumen of the pulmonary artery according to Muller is performed. Or they carry out a radical correction of the defect - a patch is made from the pericardial tissue.
Forecast
There are frequent cases when defective "holes" close by themselves towards the end of the mother's pregnancy, or some time after birth. This happens because after birth, the baby’s circulatory system seems to start up again, and the pressure changes - all this can positively affect the baby and lead to a cure. Only supportive medications can be prescribed by a doctor, and regular ultrasound procedures.
In the presence of a ventricular septal defect, one should not be inactive and let the course of the disease take its course. Only in extremely rare cases, the defect does not significantly affect the quality andlifespan.
For the most part, it poses a real danger and threat to human life. Life expectancy with the above defect directly depends on the size of the defect, but on average, the figures vary from 20 to 25 years. A more frightening reality points to the statistics of 50 to 80% of deaths in children before reaching 6 months or one year of age. Therefore, it is very important to recognize the first signs and symptoms, identify the disease in time and take correct and timely steps to eliminate it.
