aortic stenosis
Introduction
Introduction to aortic stenosis Aortic stenosis (congenitalaorticstenosis) can be located on the valve, under the valve, or on the valve. Such as aortic stenosis, thickening of the semilunar valve, fusion into a diaphragm, a small mouth in the center, the ascending aorta often expands. If the left ventricular outflow tract has an annulus fibrosus or fiber band 5 to 10 mm below the aortic orifice, a subvalvular stenosis may be formed. Intravalvular stenosis causes wrinkles due to the loss of elasticity of the aortic wall distal to the aortic valve, which hinders the left ventricle from obstructing blood. Aortic valve stenosis is the least common in the stenosis of the above three different sites. The relative incidence of this disease is lower in our country. Aortic stenosis includes several types of cardiac vascular malformations that cause left ventricular obstruction. The incidence is about 3 to 5% in congenital heart vascular malformations. It is more common in male patients. The ratio of male to female is about 3 to 4:1. . basic knowledge The proportion of illness: 0.003 ~ 0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: heart failure
Cause
Cause of aortic stenosis
Cause:
At the 4th week of embryonic arterial co-drying, the aorta-pulmonary artery is divided into the aorta that passes into the left ventricle and the common pulmonary artery that passes into the right ventricle. Three and a half moon lobes are then grown on the inner wall of the aorta and common carotid artery roots. If the arterial coherence is unevenly divided, the semilunar valve and/or the aortic roots are abnormally developed, and the aortic valve, annulus, or stenosis may be present after birth. Congenital aortic valve stenosis may also be accompanied by an aorta. The subvalvular fibrous septum is narrow, or the aortic valve is narrow, and often has aortic coarctation or mitral and left ventricular dysplasia. Therefore, in recent years, it is believed that the cause of at least a part of aortic stenosis is related to the serious imbalance of left and right ventricular discharge in the fetal period. Under normal circumstances, the blood flowing from the inferior vena cava into the right atrium enters the left atrium through the foramen ovale and is then discharged through the left ventricle. After the blood flowing from the superior vena cava into the right atrium is sent to the pulmonary artery through the right ventricle, most of the transarterial catheter enters the descending aorta, and only a small part enters the pulmonary circulation. If the follicular hole in the fetal period is small and the blood flow resistance is high, the blood flowing from the inferior vena cava into the right atrium will enter the right ventricle, resulting in a significant decrease in left ventricular discharge, affecting the mitral valve, left ventricle, aorta and Normal growth and development of the ascending aorta.
Prevention
Prevention of aortic stenosis
Congenital diseases, there is no preventive method. Prepare the expectant mother who wants the child to avoid all harmful factors and cultivate healthy living habits.
Complication
Aortic stenosis complications Complications heart failure
It varies depending on the degree of aortic stenosis. Mild stenosis, good prognosis, can live to the elderly, but can be complicated by subacute bacterial endocarditis. Severe stenosis increases with age, stenosis, and death in childhood due to myocardial hypoxia and ventricular fibrillation. As for death due to left ventricular failure, it is rare. In severe cases of aortic stenosis in infants, they die of heart failure.
Symptom
Symptoms of aortic stenosis Common symptoms Fatigue in the precordial area, dyspnea, fainting, heart failure
The disease is more common in men. The severity of the symptoms depends on the degree of stenosis. If the stenosis exceeds 25% of the normal area of the aortic orifice, that is, the aortic orifice may decrease in the child to 0.6cm2, such as developmental disorders, fatigue, difficulty breathing, fainting, precordial pain, heart failure and even sudden death. Wait. Generally, it is asymptomatic and has no prognosis: the mortality rate of this disease is low, generally about 2%, the surgical effect is satisfactory, and the postoperative symptoms are improved or completely disappeared, which can return to normal life. At the same time, we must pay attention to prevent some postoperative complications.
Examine
Aortic stenosis examination
Cardiac examination
The size of the heart is normal or enlarged, and the systolic tremor is twitched between the 2rd and 4th ribs of the right sternal border of the sternum or the 3rd and 4th ribs of the left edge, and the jet murmur of grade III to IV can be heard, and the rhythm is formed on the heart sound map. Conducted on the right neck, back, apex, and even the elbow. Sometimes the early contraction sound is heard in the aortic valve area, and the second heart sound in the aortic valve area is normal or weak. If the aortic stenosis is accompanied by aortic regurgitation, there is a high-pitched diastolic murmur in the aortic valve area.
The peripheral arterial pressure is normal or decreased, such as severe stenosis, and the pulse pressure is lower than normal.
2. X-ray inspection
The shape of the heart is normal or enlarged, with the left ventricle increasing, and the contraction is strong under fluoroscopy. The ascending aortic shadow is also widened by the expansion after stenosis. The left atrium enlarges in the right anterior oblique position during meal.
3. ECG examination
Normal or showing left ventricular hypertrophy with myocardial strain. Standard lead I, II and pre-cardiac lead V5, V6, T-wave inversion can be seen.
4. Echocardiography
The active lobes between the aortic root curves cannot see normal opening and closing, showing a thicker curve, moving synchronously with the root curve. Sometimes open, but the extent of separation is small. The diameter of the ascending aorta is relatively small compared to the diameter of the aortic root at the valve level. The left ventricular wall and interventricular septum thickened significantly. The Doppler technique can also be used to estimate the transvalvular pressure difference.
5. Cardiac catheterization
Right heart catheterization is not helpful, only showing increased pulmonary microvascular, pulmonary artery and right ventricular pressure. Left heart catheterization revealed a decrease in systolic blood pressure and an increase in left ventricular systolic pressure in the ascending aorta or peripheral arteries. The pressure difference between the two was significant, indicating a narrowing of the aortic orifice. The peripheral arterial pressure curve rises slowly, rising on the branch and having a notch. Left ventricular angiography revealed the extent and extent of left ventricular wall thickening and aortic stenosis.
Diagnosis
Diagnosis and differentiation of aortic stenosis Because of the obvious murmur and left ventricular hypertrophy, this disease needs to be differentiated from ventricular septal defect and patent ductus arteriosus. Identification relies primarily on right heart catheterization.
