What is meant by aortic stenosis? Aortic stenosis refers to structural and morphological changes in the aortic valve leaflets due to various causes, junctional adhesions, abnormal aortic valve leaflet motion during cardiac contraction, reduced open area, obstruction of blood flow at the level of the aortic valve leaflets, and the appearance of transvalvular pressure difference. What are the causes of aortic stenosis? Common causes are congenital aortic valve anomalies; rheumatic aortic valve lesions; and age-related calcification. What kind of damage does aortic stenosis do to the body? In general, the normal adult aortic valve opening area is about 3.0~-4.0 cm2. according to the size of the aortic valve opening area, the degree of stenosis is graded as follows: mild stenosis: area >1.5 cm2; moderate stenosis: area 1.0~1.5 cm2; severe stenosis: area ≤1.0 cm2, the transvalvular pressure difference is generally >50mmHg when the heart function is normal. patients with aortic stenosis can have no clinical symptoms for many years, and their quality of life is not affected. Symptoms of chest pain, syncope, and congestive heart failure appear only gradually when the valve orifice area is less than 1 cm2. The left ventricular ejection resistance increases, and both the left ventricular free wall and septum hypertrophy to accommodate the increased ventricular wall tension. Left ventricular hypertrophy causes decreased compliance, resulting in increased left ventricular end-diastolic pressure and subendocardial myocardial ischemia. Myocardial hypertrophy and elevated systolic pressure can increase myocardial oxygen consumption. On the other hand, due to valve stenosis, coronary and body circulation perfusion is reduced, myocardial ischemia is aggravated, and angina pectoris occurs. Syncope may occur with reduced blood flow in the body circulation. In the decompensated phase, left ventricular afterload and wall tension increase, left ventricular systolic function decreases, the left ventricle becomes dilated, cardiac output decreases, and the patient enters the end-stage heart failure. What are the clinical manifestations of aortic stenosis? Some patients with moderate stenosis may show chest tightness and shortness of breath when the activity increases. Patients with severe stenosis often have symptoms of chest pain, vertigo, syncope and heart failure, and a small number of patients with severe stenosis can die suddenly after strenuous activity. 2. Signs: Systolic murmur of grade III/6 or higher in the aortic valve area, often accompanied by systolic tremor, conducted toward the neck. In patients with significant septal thickening, the mitral valve may show the SAM sign, and a systolic blowing murmur may be heard in the apical region. In younger patients, upper and lower extremity blood pressure should be measured to except for combined aortic arch narrowing. How to make the diagnosis and differential diagnosis of aortic stenosis? Diagnostic points: 1. The above clinical manifestations and signs. 2. ECG: left ventricular hypertrophy and strain. Some patients may be normal. 3, Chest X-ray: enlarged left ventricle, calcification is seen in the aortic valve area, and the ascending aorta is often dilated after stenosis. In some elderly patients, calcification can involve the aortic sinus and ascending aortic wall, and the chest X-ray has corresponding performance. In combination with aortic constriction, the intercostal vessels are thickened, and rib cut marks can be found on chest radiograph. 4.Echocardiography can detect aortic valve leaflet thickening, deformation, calcification, and limitation of activity. In severe cases of calcification, the aortic annulus and anterior mitral valve leaflet may be involved. The aortic flow velocity is increased and the transvalvular pressure difference is increased. The ascending aorta shows post-stenotic dilatation and thickening of the septum and left ventricular wall. In some patients, severe hypertrophy of the left ventricle, especially in the upper part of the septum, can lead to narrowing of the left ventricular outflow tract with signs of mitral SAM, and ultrasound suggests increased flow velocity in both the aortic valve and the left ventricular outflow tract. 5, coronary angiography age greater than 50 years; or age between 40-50 years, with chest pain, other symptoms of myocardial ischemia; or with high risk factors for coronary heart disease, coronary angiography should be routinely performed to clarify the presence of combined coronary heart disease before performing surgical procedures. The disease should be differentiated from the following diseases: 1. congenital supra-aortic stenosis and congenital subaortic stenosis These patients have a younger age of onset, while patients with aortic stenosis are less likely to have onset before the age of 20. Careful echocardiographic examination can clarify the diagnosis. Occasionally, patients with aortic stenosis combined with congenital supra-aortic stenosis are seen clinically, and the latter is easily missed. 2, primary hypertrophic obstructive cardiomyopathy can be clearly diagnosed by echocardiography. Patients often have septal hypertrophy, left ventricular outflow tract stenosis, increased blood flow, and the phenomenon of SAM sign in the anterior mitral leaflet. How is aortic stenosis treated? Patients with asymptomatic mild to moderate aortic stenosis should routinely have an electrocardiogram, chest radiograph, and echocardiogram once a year. Surgery should be performed if the following conditions are met: 1. Symptomatic, severe aortic stenosis, or transvalvular pressure difference > 50 mmHg. 2. Ascending aorta or other heart valve lesions requiring surgical treatment, combined with severe aortic stenosis. 3, Coronary artery disease, ascending aorta or heart valve pathology requiring surgical treatment, combined with moderate aortic stenosis. 4.Asymptomatic, severe aortic stenosis with simultaneous manifestation of impaired left ventricular systolic function. Or severe aortic stenosis with abnormal manifestations after activity.