pulmonary atresia
Introduction
Introduction to pulmonary atresia Complete ventricular septal atresia refers to the complete atresia of the pulmonary valve, tricuspid valve structure and dysfunction, different degrees of dysplasia in the right ventricle, intact ventricular septum, and congenital heart malformations with normal relationship between the atrioventricular and ventricular large vessels. Its incidence accounts for about 1% to 3% of congenital heart disease, and accounts for about 30% of neonatal congenital heart disease. Abnormalities in the development of the ventricles, the separation of the arterial trunk, and the development of the pulmonary valve can cause atresia of the pulmonary valve, usually in the later stages of cardiac embryo development. Hunter first described the pathological features of the disease as early as 1783, and Novelo and colleagues reported its clinical features in 1951. In 1983, Peacock was first named as a ventricular septal intact pulmonary atresia. Once diagnosed, surgery should be performed. Most of the surgery is treated with staged surgery. Prostaglandin E1 was administered intravenously after birth to delay the closure time of the arterial catheter. Proximal-pulmonary shunt, or simultaneous pulmonary valve incision in extracorporeal circulation; Phase 2 establishes a right ventricle-to-pulmonary blood flow channel at 3 to 5 years of age, closing room traffic and extracardiac shunt. basic knowledge The proportion of illness: 0.015% Susceptible people: more common in young children Mode of infection: non-infectious Complications: heart failure
Cause
Cause of pulmonary atresia
With ventricular septal defect, also known as pseudo-arterial trunk, is the most serious type of tetralogy of Fallot. Due to pulmonary valve atresia or absence, there is no channel between right ventricle and pulmonary artery. The pulmonary trunk itself may be blocked or stunted. . The blood from the ventricles of the left and right ventricles is all injected into the aortic pulmonary circulation from the arterial catheter or the bronchial artery. The ventricular septum is complete with right ventricular dysplasia, the right ventricular wall is thick, and the tricuspid valve is small; because the right ventricle is a blind cavity, the blood returns to the right atrium during contraction; the blood from the vena cava back to the right atrium can only Enter the left atrium, left ventricle, and aorta through a patent foramen ovale or atrial septal defect. The blood of the pulmonary circulation comes from the arterial catheter or the collateral circulation of the bronchial artery.
Pathophysiology
Pulmonary atresia of the pulmonary valve has two pathological types, one is a fusion of three thickened leaflets, the combined sacral line is in the center, mostly accompanied by right ventricular funnel atresia or severe stenosis, or with tricuspid regurgitation And the tricuspid valve moves down.
Another type of thickened valve is completely occluded, but the combined sacral line is only around, and the center is a smooth fibrous membrane that protrudes into the pulmonary trunk. This type of right ventricular funnel has no obvious stenosis. Right ventricular dysplasia is mild. The pulmonary valve ring is often underdeveloped, the pulmonary artery is often smooth or slightly less than normal, and the main pulmonary artery is completely absent, accounting for about 4%.
Tricuspid valve lesions usually exist, with 30% chordae fusion, some leaflet tissue is mechanized, about 25% with tricuspid valvular deformity, causing severe tricuspid regurgitation or stenosis, occasional tricuspid valve deficiencies Such as. The size of the tricuspid annulus is proportional to the right ventricular cavity. In patients with very small right ventricular cavity, the tricuspid valve is severely stenotic, the annulus becomes smaller and the obstruction becomes smaller, the valve leaf is thickened, the chordae tendine is shortened, and there is no sacral space and papillary muscle. Therefore, the diameter of the tricuspid annulus can indirectly reflect the size of the right ventricular cavity. The heavier the tricuspid valve is, the smaller the right ventricular cavity is, and the higher the right ventricular pressure. The enlargement of the right atrium is closely related to the degree of tricuspid regurgitation.
Generally, there are different degrees of right-to-left shunt traffic openings through the interatrial septum, including patent foramen ovale and atrial septal defect.
There are different degrees of dysplasia in the right ventricle. Greenwold was divided into two types according to ventricular morphology in 1956: it has a small right ventricular cavity type I, often accompanied by tricuspid stenosis. Large right ventricular cavity is type II, often accompanied by tricuspid valvular malformation or dysplasia, severe tricuspid regurgitation, thinning of the right ventricular wall, and even no myocardium. This type is rare. Bull and de Leval divide the disease into three types according to the presence or absence of the inflow, trabecular and funnel parts of the right ventricular cavity: type I is present in the right ventricular cavity, and the right ventricular cavity is more or less present. Dysplasia, type II is absent in the right ventricular trabecular, right ventricular cavity is small, type III is the right ventricular trabecular and funnel parts are absent. This classification has certain clinical guiding significance for surgical treatment. Right ventricular intraluminal hypertension can lead to fibrosis of the intima, and diastolic compliance is reduced. Complete ventricular septal atresia combined with coronary artery abnormalities, and Cader and Sage autopsy found that right ventricular-coronary artery spasm was found in 60% of cases. About 10% of cases have stenosis or atresia of one or more coronary arteries, and the blood supply to the distal myocardium comes from the right ventricle.
Myocardial ischemia, hypoxia, and even infarction can be caused by right ventricular blood supply with low blood oxygen saturation saturation. This coronary artery malformation has been confirmed in both clinical and autopsy cases in cases where the tricuspid annulus and the right ventricular cavity are very small. In addition, in autopsy, 17% of patients with coronary artery stenosis were single coronary arteries, and coronary artery abnormalities crossed the right ventricular outflow tract.
Prevention
Pulmonary atresia prevention
1. Influence of environment on complete pulmonary atresia in pediatric septum
Ask about family history to understand the genetic situation and investigate the impact of environmental factors to explore the cause of congenital heart disease. Shaw investigates the address of the address to understand the environmental teratogenic factors that the pregnant mother may be exposed to. The address of the mother's production is sometimes used to represent the address of the early pregnancy to estimate environmental factors. According to survey data, the address of the mother at birth and at the time of production, about 24.8% of mothers moved between starting pregnancy and production. Therefore, observing the production address may reduce the positive result of the association of congenital malformation with the mother's exposure to the environment. It is necessary to investigate the environment of the address at the time of pregnancy.
2. Effect of chromosomal abnormalities on pediatric septal intact pulmonary atresia
Schwanitz argues that the detection of cardiac malformations during birth can be used as an indication for chromosomal examination. The authors mentioned that 588 fetuses were diagnosed with growth retardation and/or congenital malformations before birth, and 116 of these cases (19.7%) were found to have chromosomal abnormalities. Among these malformed fetuses diagnosed before birth, there were 102 (17.3%) fetuses with cardiac malformations, and therefore, cardiac malformations were the most common malformations. Of the fetuses diagnosed with cardiac malformations before birth, 41 fetuses (40.2%) had chromosomal abnormalities (the most common of 18 and 21 trisomy).
3. Effect of dietary therapy during pregnancy on pediatric septal intact pulmonary atresia
If the mother begins a dietary treatment before pregnancy, it may prevent damage to the fetus. Therefore, if you have a deep understanding of the cause, you can monitor the maternal disease and fetal malformation from the pregnant mother and the fetus before pregnancy and pregnancy. If possible, try to prevent fetal congenital malformation. However, from the perspective of genetics and environmental damage, the cause of congenital heart disease is not fully understood, and most of them are powerless in prevention. Therefore, explaining the cause and fundamentally preventing the occurrence of congenital heart disease is still extremely The arduous task requires the joint efforts of scholars in clinical and basic fields.
Complication
Pulmonary atresia complications Complications heart failure
Often complicated by congestive heart failure and low cardiac output syndrome.
Symptom
Pulmonary atresia symptoms Common symptoms Liver big purpura two lungs diffuse or scattered... Shortness of breath and palpitations
More than 90% of children develop purpura at birth or shortly after birth, and progressively worse. The degree of purpura depends primarily on blood flow to the lungs through the arterial catheter and other body-pulmonary vessels. If the arterial catheter is small, the purpura is heavy, and the survivors have clubbing (toe). Growth and development disorders, often after the activity, palpitations are short, but rare. If the body-lung traffic is large, the purpura is lighter and prone to respiratory infections, and heart failure can often occur early. If the arterial catheter tends to close, the purpura is progressively aggravated. In severe cases, the arterial oxygen partial pressure can be reduced to 20 mmHg, and the oxygen saturation is only about 40%. Right heart failure is more common in patients with tricuspid regurgitation, with hepatomegaly, edema, and apical area. If the child is born, the general child can develop well, with purpura after birth, difficulty breathing and metabolic acidosis.
Examine
Pulmonary atresia check
Chest X-ray, electrocardiogram, cardiac color ultrasound, CT, MRI, right heart catheterization and cardiac angiography.
Diagnosis
Diagnosis and diagnosis of pulmonary atresia
diagnosis
Diagnosis can be made by signs, chest X-ray, electrocardiogram, cardiac color ultrasound, CT, MRI, right heart catheterization and cardiac angiography. CT and MRI can show the development of pulmonary artery and the establishment of collateral circulation. Right heart catheterization and cardiac angiography are the key to show the disease.
Differential diagnosis
1. The clinical manifestations of ventricular septal defect are similar to those of tetralogy of Fallot, except that cyanosis occurs earlier than quadruple disease, which occurs several days after birth. The systolic murmur is often lighter, and the chest and back may be heard from the artery. Continuous murmur of catheter patency or bronchial collateral circulation. After the first heart sound, the early contraction sound is often heard, and the second heart sound at the bottom of the heart is enhanced and single. X-ray examination showed that the heart shadow increased, the heart and waist were obviously depressed, and the lobes of the bronchus may be seen in the lungs. Echocardiography can confirm the diagnosis.
2. The complete clinical manifestations of ventricular septum are similar to severe pulmonary stenosis, and most of the children die within a few days after birth. If the arterial catheter is continuously open and the hypoxia is mild, the sick child may survive for several weeks, but under normal circumstances, the bruising is significant, the hypoxia is severe, and there is a paroxysmal attack, which is easy to merge with heart failure and enlarge the liver. The jugular vein is only high in waves. Continuous murmurs can often be heard, from patent ductus arteriosus or only mild systolic murmurs, from tricuspid regurgitation, the second heart sound at the bottom of the heart is single, due to the disappearance of the pulmonary valve closure sound, X-ray examination of the heart shadow Mild or extremely increased, the heart and waist are obviously depressed, and the lung field blood vessels are reduced. The electrocardiogram showed a high P-point and a right ventricular dysplasia, showing left ventricular hypertrophy, but the motor axis was often in the normal range or mild right deviation, which is different from the left axis of the tricuspid atresia. Echocardiography can confirm the diagnosis. Pulmonary atresia, right ventricular cavity size, wall thickness, tricuspid valve morphology and opening and closing function can be displayed, and the size of the foramen ovale or atrial septal defect can be measured. Cardiac catheterization can increase the right atrium and right ventricle. The cardiovascular angiography can confirm that the right ventricle is a blind cavity. The contrast agent is from the right atrium through the atrial septal defect. It enters the left atrium, the left ventricle and the aorta. Enter the passage of the lung circulation.
