Partial heterotopic pulmonary vein connection in children
Introduction
Brief introduction of partial pulmonary venous connection in children Partial pulmonary venous connection refers to the abnormal drainage of one or several (but not all) of the pulmonary veins in the four pulmonary veins, directly or indirectly connected to the right atrium. basic knowledge Probability ratio: Susceptible people: young children Mode of infection: non-infectious Complications: pulmonary hypertension
Cause
Partial pulmonary venous connection in children
(1) Causes of the disease
The key period of cardiac embryo development is that in the second to eighth weeks of pregnancy, congenital cardiovascular malformations also occur mainly at this stage. There are many reasons for the occurrence of congenital heart disease, which are roughly divided into internal and external types. Among them, the latter are more common, and the internal factors are mainly related to heredity, especially chromosomal translocations and aberrations, such as 21-trisomy syndrome, 13-trisomy syndrome, 14-trisomy syndrome, 15-trisomy syndrome. And 18-trisomy syndrome, etc., often associated with congenital cardiovascular malformations; in addition, the incidence of cardiovascular malformations in children with congenital heart disease is significantly higher than the expected incidence, the most important external factors are intrauterine infection Especially viral infections such as rubella, mumps, influenza and Coxsackie virus; others such as exposure to large doses of radiation during pregnancy, use of certain drugs, metabolic diseases or chronic diseases, hypoxia, maternal age (close to Menopause), etc., all pose a risk of congenital heart disease.
(two) pathogenesis
Pathological anatomy
Partial pulmonary vein connection abnormalities may exist alone, or combined with other cardiac malformations, the most common is sinus atrial septal defect, rare mitral stenosis, right ventricular double outlet, ventricular septal defect, tetralogy of Fallot, pulmonary artery Narrow, aortic coarctation, patent ductus arteriosus, right heart, etc. There are many types of this disease, such as the right superior pulmonary vein directly into the right superior vena cava, the right pulmonary vein connected to the right atrium, the right pulmonary vein connected to the inferior vena cava, and the left pulmonary vein. Left unnamed vein connection, the right pulmonary vein and the right superior vena cava are the most common, the right pulmonary vein abnormalities are more common than the left pulmonary vein, the ipsilateral pulmonary veins into the ipsilateral atrium can be seen in the heart and spleen syndrome and the common atrium.
(1) The right pulmonary vein is connected with the right superior vena cava or the right atrium: the most common, accounting for 3/4, the pulmonary veins of the upper and middle lobe of the right lung are connected to the superior vena cava respectively at the entrance of the azygous vein and the right atrium, the junction of the superior vena cava. Between the right lower lobe and the pulmonary veins normally return to the left atrium, often with a sinus atrial septal defect, and occasionally the superior vena cava ride across the defect.
(2) The right pulmonary vein is connected to the inferior vena cava: all right pulmonary veins (even in the right lung, lower pulmonary veins) form a common trunk into the inferior vena cava. This type is rare, and the connection between the common and inferior vena cava is common. On the chest radiograph, the right lower lung field has a characteristic crescent-shaped shadow, so it can also be called "scimitar syndrome", which is accompanied by cardiac ectopic, right lung dysplasia, aortic abnormal blood vessels supply right lung Equal deformity.
2. Pathophysiology
The pulmonary vein obstruction has not been found in this disease, so the hemodynamic characteristics are only left-to-right shunt of some connected pulmonary veins. The abnormal blood flow of single pulmonary veins accounts for only 20% of all pulmonary venous blood flow, so there is no obvious clinical manifestation. .
In patients with atrial septal defect, hemodynamic changes include atrial level, left-to-right shunt at the level of pulmonary veins, pulmonary hypertension is less common, but children with machete syndrome, if accompanied by lung consolidation, pulmonary muscle layer Thick, pulmonary vascular resistance increases, pulmonary hypertension can occur.
Prevention
Partial pulmonary venous connection prevention in children
The occurrence of congenital heart disease is a comprehensive result of various factors. In order to prevent the occurrence of congenital heart disease, publicity and education of popular science knowledge should be carried out, and key populations should be monitored to give full play to the role of medical staff and pregnant women and their families.
1. Get rid of bad habits, including pregnant women and their spouses, such as smoking, alcohol and so on.
2. Actively treat diseases affecting fetal development before pregnancy, such as diabetes, lupus erythematosus, anemia, etc.
3. Actively do prenatal checkups to prevent colds. Try to avoid using drugs that have been proven to have teratogenic effects and avoid contact with toxic and harmful substances.
4. For older women, there is a family history of congenital heart disease, and one of the couples with serious diseases or defects should be monitored.
Complication
Partial pulmonary venous connection complications in children Complications pulmonary hypertension
In severe cases, pulmonary infection can occur repeatedly, and obstructive pulmonary hypertension occurs in advanced stages.
Symptom
Partial pulmonary venous connection symptoms in children Common symptoms Systolic murmur ventricular septal defect Fatigue shortness of heart enlargement of anterior region of heart failure
Single pulmonary ectopic venous connection has no clinical symptoms; one side of the pulmonary vein ectopic drainage, the symptoms are similar to the non-obstructed type of complete pulmonary ectopic connection, cyanosis is not common, heart failure is also rare, with atrial septal defect, The physical examination is mainly based on the sign of atrial septum. If the septum is intact, the second heart sound can be heard. The splitting sound is wide but not fixed. It changes with the breathing, and the pulmonary valve can have systolic murmur.
Examine
Examination of partial pulmonary venous connection in children
Chest X-ray
Moderate left-to-right shunt, X-ray findings are similar to medium-sized atrial septal defect, ie, more pulmonary blood, enlarged right ventricle, sometimes ectopically connected veins, and ectopic angulation of the pulmonary vein to the left innominate vein. ".
2. ECG
Similar to the atrial septal defect, the V1 lead rsr' or rsR', but the atrial septum is intact and there is only a small left-to-right shunt in the pulmonary vein opening, and the electrocardiogram is often normal.
3. Echocardiography
Cardiac ultrasound is difficult to diagnose the four pulmonary vein openings of the disease. Sometimes, even if the pulmonary veins are completely normal, it is unclear. When there is no atrial septal defect and the right ventricular volume load increases, some partial pulmonary venous connection must be considered. When there is a sinus atrial septal defect, the right pulmonary vein ectopic opening in the right atrium can be seen in the lower plane of the xiphoid; in the later part, the venous venous opening in the coronary sinus can be displayed; suspected scimitar syndrome In children, the xiphoid process is long and the short axis is cut. The inferior vena cava and the junction of the inferior vena cava and the right atrium can be seen, so that the ectopically connected pulmonary veins can be displayed. The vertical vein can be displayed from the short axis of the sternum, sometimes the heart ultrasound can be very Correct diagnosis of the disease, but even if the pulmonary vein is not captured by the ectopic opening, the disease cannot be ruled out.
4. Cardiac catheter
Most of the disease does not require cardiac catheterization. It is only used to diagnose cases with unknown etiology and to understand the pulmonary artery direction of patients with machete syndrome, lung consolidation, selective pulmonary angiography, and observation of pulmonary venous return to show the ectopic connection of pulmonary veins. If the catheter can be inserted into the pulmonary vein, selective pulmonary venography can clearly show the anatomical location of the pulmonary vein; in the scimitar syndrome, selective angiography of the aorta is also necessary.
5. Other non-invasive imaging
Both CT and MRI can be used for the diagnosis of this disease. In the non-invasive examination, this may be the most accurate, except for the presence of lung deformity and other malformations.
Diagnosis
Diagnosis and diagnosis of partial pulmonary venous connection in children
diagnosis
Diagnosis can be confirmed based on clinical manifestations and auxiliary examinations.
Differential diagnosis
1. Chest X-ray: moderate left-to-right shunt. X-ray findings are similar to those of moderate atrial septal defect, ie, more pulmonary blood, enlarged right ventricle, and sometimes ectopically connected veins. When the pulmonary vein is ectopically connected to the left innominate vein, a "snowman sign" may occur.
2, ECG: similar to atrial septal defect. Expressed as V1 lead rsr' or rsR'. However, the septum was intact and there was only a small left-to-right shunt in the pulmonary vein opening, and the electrocardiogram was normal.
3. Echocardiography: Cardiac ultrasound is difficult to diagnose the four pulmonary vein openings of the disease, and sometimes it is unclear even if the pulmonary veins are completely normal. Partial pulmonary venous connection must be considered when there is an increase in right ventricular volume load without atrial septal defect. When there is a sinus atrial septal defect, the right pulmonary vein ectopic opening in the right atrium can be seen in the lower plane of the xiphoid; in the later part, the venous venous opening in the coronary sinus can be displayed; suspected scimitar syndrome In the case of the lower and short axis of the xiphoid process, the inferior vena cava and the junction of the inferior vena cava and the right atrium can be seen, and the ectopically connected pulmonary veins can be displayed; the vertical vein can be displayed from the short axis of the sternum. Sometimes cardiac ultrasound can diagnose the disease very accurately. But even if the pulmonary veins with ectopic openings are not captured, the disease cannot be ruled out.
4, cardiac catheter: Most of the disease does not require cardiac catheterization, it is only used to diagnose cases of unknown etiology and to understand the direction of pulmonary artery and lung consolidation in patients with saber syndrome. Selective pulmonary angiography, observe the pulmonary venous return to show the ectopic connection of the pulmonary vein; if the catheter can be inserted into the pulmonary vein, selective pulmonary venography, can clearly show the anatomical location of the pulmonary vein; in the saber syndrome, the selective angiography of the aorta is also very necessary.
