complete transposition of the great arteries
Introduction
Introduction to complete transposition of great arteries Complete transposition of greatarteries refers to the position of the aorta and pulmonary artery. The aortic valve is not normally in the right posterior aspect of the pulmonary valve but in the right front, and the right ventricle is located. The pulmonary valve is in the left posterior of the aortic valve and the left ventricle. . The position of the left and right atrium ventricles, as well as the relationship between the atrium and the ventricles, remains unchanged. The venous blood returns to the right atrium and the right atrium and then the aorta goes to the whole body. Oxygenated blood is returned to the left atrium and the left ventricle, and the pulmonary artery is still in the lungs, so that the systemic circulation and the pulmonary circulation go all the way and lose the circulatory interaction. In principle, there must be an exchange of blood flow in the absence of atrial septum, ventricular septum or patent ductus arteriosus, and the infant can survive temporarily. Complete transposition of the great arteries is the most common cyanotic congenital heart disease in the neonatal period, with an incidence of 0.20.3. About 5% to 7% of the total number of congenital heart diseases, the second place in the cyanotic congenital heart disease, the ratio of male to female disease is 2 to 4:1. The incidence of diabetic maternal mothers is 11.4 times higher than that of normal mothers. The incidence of pregnant women who have used hormones and anticonvulsants in early pregnancy is higher. If not treated, about 90% of patients die within 1 year of age. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: heart failure ventricular septal defect
Cause
Complete aortic transposition
Genetic factors (45%):
Complete aortic dislocation (TGA) is due to the fifth to seventh week of embryonic development, mediastinal torsion or non-helical torsion, resulting in the transposition of the main and pulmonary arteries, so the body and pulmonary circulation become independent cycles, that is, the veins of the body veins. The blood flows back into the right atrium and right ventricle, and reaches the tissues and organs of the whole body through the aorta. The arterial blood of the pulmonary veins flows back into the left atrium and the left ventricle, and reaches the lungs through the pulmonary artery, so the child is difficult to survive. If there are other cardiac malformations, there is a shunt channel between the two cycles, then a small amount of mixed blood can be exchanged for temporary life. The flow rate on both sides is different, and it can cause pulmonary hypertension, obstruction, ventricular dilatation, hypertrophy, heart failure and death.
Anatomical factors (15%):
Under normal circumstances, the cone under the pulmonary valve develops, the pulmonary artery is located in the left anterior superior; the aortic subvalvular atrophy, the aorta is located in the right lower back. When the aorta is transposition, the conus of the aortic valve is developed and is not absorbed. The aorta is located in the right anterior and superior anterior; the lung is moved forward and the conus is atrophy, and the pulmonary artery is located in the left posterior and posterior. In this way, the pulmonary artery is connected backward to the left ventricle, and the aorta is connected to the right ventricle; the aortic valve is connected to the tricuspid valve due to the presence of a cone; there is no cone under the pulmonary valve, and the mitral valve is fiber-connected. Common malformations include atrial septal defect or patent foramen ovale, ventricular septal defect, patent ductus arteriosus, and pulmonary stenosis.
Pathophysiology:
Complete transposition of the great arteries without two other abnormalities results in two parallel cycles. The venous blood from the superior and inferior vena cava is supplied to the aorta through the aorta of the right heart, and the oxygenated blood from the pulmonary vein is injected into the lung through the left heart into the translocated pulmonary artery. Patients must rely on intracardiac traffic (foramen ovale, atrial septal defect, ventricular septal defect) or extracardiac communication (arterial patent ductus arteriosus, collateral vessels) for blood flow mixing. The hemodynamic changes of this disease depend on whether it is accompanied by other malformations, the degree of communication between the left and right heart and blood, and whether the pulmonary artery is narrow. According to whether the ventricular septal defect and pulmonary stenosis are combined, the complete transposition of the great arteries can be divided into three categories:
(1) complete transposition of major arteries and complete ventricular septum: right ventricular load increased and enlarged hypertrophy, with normal pulmonary vascular resistance decreased, left ventricular pressure decreased, and ventricular septum often biased to the left ventricle. The two only rely on the closed foramen ovale and the arterial catheter to communicate and mix, so the cyanosis and hypoxia are serious.
(2) Complete transposition of the great arteries with ventricular septal defect: complete transposition of the great arteries with ventricular septal defect can make the left and right heart blood communication more mixed, so that the bruising is reduced, but the increase of pulmonary blood flow can lead to heart failure.
(3) Complete arterial translocation with ventricular septal defect and pulmonary stenosis: hemodynamic changes are similar to tetralogy of Fallot.
Prevention
Complete transposition of great arteries
Preoperative treatment: For infants with severe hypoxia, intravenous infusion of prostaglandin E1 or prostaglandin E2 should be performed before the transfer to the tertiary hospital to dilate the arterial catheter. Metabolic acidosis can be intravenously injected with sodium bicarbonate to correct the acid. Poisoned. Balloon ostomy can be used as the initial palliative operation. Under the direct vision monitoring of X-ray or echocardiography, the catheter is inserted from the femoral vein. After the inferior vena cava to the right atrium, the foramen ovale is pushed into the left atrium, and the catheter is located in the left atrium to expand the balloon. Pull the catheter lightly and quickly to tear the balloon apart. This method can improve the hypoxic state of the systemic circulation.
Complication
Complete transposition of major arteries Complications, heart failure, ventricular septal defect
Complete transposition of the great arteries without two other abnormalities results in two parallel cycles. The venous blood from the superior and inferior vena cava is supplied to the aorta through the aorta of the right heart, and the oxygenated blood from the pulmonary vein is injected into the lung through the left heart into the translocated pulmonary artery. Patients must rely on intracardiac traffic (foramen ovale, atrial septal defect, ventricular septal defect) or extracardiac communication (arterial patent ductus arteriosus, collateral vessels) for blood flow mixing. The hemodynamic changes of this disease depend on whether it is accompanied by other malformations, the degree of communication between the left and right heart and blood, and whether the pulmonary artery is narrow. According to whether the ventricular septal defect and pulmonary stenosis are combined, the complete transposition of the great arteries can be divided into three categories:
(1) complete transposition of major arteries and complete ventricular septum: right ventricular load increased and enlarged hypertrophy, with normal pulmonary vascular resistance decreased, left ventricular pressure decreased, and ventricular septum often biased to the left ventricle. The two only rely on the closed foramen ovale and the arterial catheter to communicate and mix, so the cyanosis and hypoxia are serious.
(2) Complete transposition of the great arteries with ventricular septal defect: complete transposition of the great arteries with ventricular septal defect can make the left and right heart blood communication more mixed, so that the bruising is reduced, but the increase of pulmonary blood flow can lead to heart failure.
(3) Complete arterial translocation with ventricular septal defect and pulmonary stenosis: hemodynamic changes are similar to tetralogy of Fallot.
Symptom
Symptoms of complete transposition of the great arteries Common symptoms Upper body compensatory hyperhidrosis clubbing (toe) After birth, there is persistent cyanotic liver and hard newborn
1. Cyanosis: It occurs early and half when it is born, and most of it begins within 1 month. As the age increases and the amount of activity increases, the cyanosis gradually increases. Cyanosis is systemic. If the patent ductus arteriosus is combined at the same time, there is a difference in purple, and the upper branch is blue and heavier than the lower limb.
2. Congestive heart failure: 3 to 4 weeks after birth, infants have symptoms such as feeding difficulties, hyperhidrosis, shortness of breath, liver enlargement and fine wet rales in the lungs. The child is often stunted.
3. Physical examination revealed early appearance of clubbing and toe. After birth, the heart can have no obvious murmur, but there is a single loud second heart sound, which is the aortic valve closing sound from the chest wall. If there is a large ventricular septal defect or a large arterial catheter or pulmonary artery stenosis, it can be heard. The noise generated by the corresponding malformation. Such as patent ductus arteriosus, continuous murmur can be heard in the second intercostal space of the left sternal border, combined with ventricular septal defect, can hear full systolic murmur in the third intercostal space of the left sternal border, combined with pulmonary stenosis can be in the sternum A systolic jet murmur is heard on the upper edge of the left edge. When the noise is louder, it is often accompanied by tremors. In general, patients with large ventricular septal defect have heart failure with pulmonary hypertension, but those with pulmonary stenosis have obvious purpura, but heart failure is rare.
Examine
Complete transposition of the great arteries
1. Echocardiography: a common method for diagnosing complete transposition of the great arteries. If the second ultrasound shows that the atrioventricular connection is normal and the ventricular aorta is not connected, a diagnosis can be established.
2. Color and spectral Doppler ultrasonography: contribute to the direction of intracardiac shunt, the determination of size and the detection of combined malformations. The catheter can be inserted directly into the aorta from the right ventricle, and the right ventricular pressure is equal to the aorta.
3. X-ray inspection.
4. Electrocardiogram.
5. Cardiovascular angiography.
Diagnosis
Diagnosis and diagnosis of complete transposition of great arteries
1 Because the main and pulmonary arteries are often arranged in the anterior-posterior position, the orthotopic slice shows a small aortic shadow, the pulmonary artery is slightly depressed, the heart is small and the heart image is "egg shape"; 2 the heart image is progressively increased; 3 most patients lung The texture is increased, and if the pulmonary artery stenosis is combined, the lung texture is reduced.
There are no special changes in the neonatal period. Infancy shows the right axis of the right axis, right ventricular hypertrophy, fashion and right atrial hypertrophy. When the pulmonary blood flow is significantly increased, the normal or left deviation of the electric axis, left and right ventricular hypertrophy may occur. When the ventricular septal defect was combined, the electric axis was left-biased and the double-chamber hypertrophy.
If the second ultrasound shows that the atrioventricular connection is normal and the ventricular aorta is not connected, a diagnosis can be established. The aorta is often located in the right front, from the right ventricle, and the pulmonary artery is located in the left posterior, from the left ventricle. Color and spectral Doppler ultrasonography facilitates intracardiac shunt direction, size determination, and detection of combined malformations.
The catheter can be inserted directly into the aorta from the right ventricle, and the right ventricular pressure is equal to the aorta. It is also possible that the pulmonary artery oximetry is higher than the aorta through the foramen ovale or atrial septal defect to the left ventricle.
In the selective left ventricular angiography, the aorta was seen from the right ventricle. The left ventricle angiography showed that the pulmonary artery originated from the left ventricle. Selective ascending aortic angiography showed the positional relationship of the aorta and whether the coronary artery malformation was combined.
