Full transposition of the main arteries: symptoms, diagnosis, treatment

Transposition of the main arteries is the most common type of congenital heart disease of the blue type in children of the first months of life. It accounts for 12-20% of all congenital heart anomalies. In older children, due to high mortality, the frequency of this defect is much less. Transposition of the main arteries is 2-3 times more common in boys.

Transposition of the main vessels develops when the aorta leaves the right ventricle, and the pulmonary artery exits from the left ventricle, which leads to the formation of two independent, circular circulatory circles - pulmonary and systemic. Symptoms primarily include cyanosis, as well as manifestations of heart failure. With auscultation of the heart, changes depend on the presence of combined congenital malformations. The diagnosis is based on echocardiography or cardiac catheterization. Radical treatment is surgical correction. It is recommended to prevent endocarditis.

With transposition of the main arteries, the aorta departs from the right ventricle. And the pulmonary artery - from the left. As a result, venous blood is spread by the aorta along a large circle of blood circulation, and oxygenated blood is carried by a small one. Two divided circles of blood circulation are formed. If there is a message between them (a defect of the interventricular or interatrial septum, an open aortic duct, an open oval window), the child is viable. The degree of hypoxemia and the amount of cross-discharge are dependent on the size of the communication. Perhaps a combination of this defect with the stenosis of the pulmonary artery, then there is no hypervolemia of the small circle of blood circulation, there are complaints of dyspnoea, similar to those in tetralogy of Fallot. For hypervolemia on a small circle of blood circulation, complaints of repeated pneumonia of a stagnant character are typical.

[1], [2], [3], [4], [5], [6], [7]

Symptoms of transposition of the main arteries

Expressed cyanosis develops within hours after birth, rapidly progressing with the development of metabolic acidosis due to decreased oxygenation of tissues. Cyanosis in patients with large VSD, an open arterial duct or a combination of them is less pronounced, but symptoms and manifestations of heart failure may appear during the first 3-6 weeks of life (eg, tachypnea, dyspnea, tachycardia, sweating, inability to gain weight). With the exception of generalized cyanosis, the results of a physical examination are not noticeable. Noises in the heart may be absent, if there are no associated defects. The second tone is single and loud.

Diagnosis of transposition of the main arteries

In most cases, the defect is diagnosed at birth by diffuse ("cast-iron") cyanosis and the presence of pronounced dyspnea. Noise is not always manifested in the early days. It corresponds to the location of the concomitant communication. Palpatorically, systolic jitter is detected. Cardiomegaly almost from the first days of life is manifested by the formation of a "heart hump".

With ECG, the deviation of the electric axis of the heart to the right is detected, signs of right ventricular overload and hypertrophy of its myocardium (positive T in the right thoracic leads). With large defects of the interventricular septum, signs of an overload of the left ventricle are revealed.

On the X-ray, the pulmonary pattern can be normal (with small communications), amplified (at large) or depleted (when combined with pulmonary artery stenosis). The shadow of the heart has an ovoid shape ("an egg lying on its side").

Echocardiography is based on the identification of the morphology of the ventricles and the main vessels that leave them. The parallel course of the ventricular and both vessels in the projection of the long axis of the left ventricle is characteristic.

Cardiac catheterization and angiocardiography have recently lost their significance, they are used to conduct Rashkind's procedure and to diagnose complex accompanying heart defects.

[8], [9], [10]

Treatment of complete transposition of the main arteries

In the preoperative period, conservative therapy of heart failure is performed. Use the infusion of prostaglandins of group E to improve the patency of the open arterial duct, for the same purpose, a closed balloon atrioseptotomy (Rashkind's procedure) is performed to increase interatrial communication. The procedure is performed under the radiological control or in modern conditions in the intensive care unit under ultrasound control. Conducting a procedure without intubation makes it possible to rapidly activate patients.

When transposition of the main arteries, accompanied by severe hypoxemia, an operative correction is shown. Operative treatment is carried out, as a rule, early, in the first month of life. There are two main options for surgical treatment: switching the blood flow at the level of the atria and switching the blood flow at the level of the main arteries. Switching blood flow at the level of the atrium is carried out by cutting out a Y-shaped patch from the xenopericardium, one end of which is hemmed so that the venous blood from the hollow veins is directed through the atrioventricular communication to the left ventricle. Through the remaining part of the atrium, arterial blood comes from the pulmonary veins through the tricuspid valve to the right ventricle and into the aorta. At the atrial switching by the systemic ventricle, the right ventricle remains. Since it is not phylogenetically designed for high-pressure operation, its pump function and tricuspid valve function gradually deteriorate, which does not allow one to hope for a long, good result.

Switching blood flow at the level of the main arteries is completely radical surgery, as the aorta and the pulmonary artery are sutured to the corresponding ventricles (to the left and right, respectively). The complexity of the operation lies in the need for coronaroplasty. The operation is performed under conditions of artificial circulation and deep hypothermia (rectal temperature is reduced to 18 ° C).