What is Aortic Stenosis?

Aortic valve stenosis is mainly caused by sequelae of rheumatic fever, congenital aortic valve structural abnormalities, or senile aortic valve calcification. Patients can be asymptomatic during the compensatory period. Most patients with severe stenosis have burnout, dyspnea (labour or paroxysmal), angina, vertigo or syncope, and even die suddenly.

Basic Information

English name: aortic valve stenosis
Visiting department: cardiology
Common causes: Caused by sequelae of rheumatic fever, congenital aortic valve structural abnormalities, or senile aortic valve calcification

Common symptoms: Angina pectoris, dizziness or syncope, dyspnea, sudden death, sweating, and palpitations

Causes of aortic stenosis

Mainly caused by the sequelae of rheumatic fever, structural abnormalities of congenital aortic valve or calcification of senile aortic valve. Because the outlet of the left ventricular outflow tract is the aortic orifice, the adult aortic valve area is 3.0 cm ² , and the blood flow will be blocked when the aortic valve area is reduced to one-third or more of normal.

Clinical manifestations of aortic stenosis

Angina pectoris

60% of symptomatic patients are often induced by exercise and relieve after rest. Occurs after exertion and can also occur at rest, suggesting that it is not necessarily related to exhaustion and physical activity. The mechanism may be caused by myocardial hypertrophy, increased myocardial oxygen demand and decreased oxygen supply secondary to excessive compression of the coronary arteries, and excessively high wall tension in the left ventricular systole.

2. Vertigo or syncope

About 30% of patients have vertigo or syncope, and the duration can be as short as 1 minute and more than half an hour. Some patients are associated with Alzheimer's syndrome or arrhythmia. Dizziness or syncope often occurs after work or when the body is bent forward, sometimes in a resting state, a sudden change of body position, or when nitroglycerin is administered sublingually to treat angina pectoris. The mechanism of this is not clear, and may be related to the following factors: Labor expands the surrounding blood vessels, and the narrow aortic port restricts the corresponding increase in cardiac output, resulting in insufficient blood supply to the brain. Transient severe arrhythmia occurred, leading to hemodynamic disturbance. carotid sinus allergy.

3. difficulty breathing

Labor dyspnea is often a manifestation of cardiac insufficiency, often accompanied by fatigue and weakness. With the increase of heart failure, paroxysmal dyspnea at night, sitting breath, coughing pink foamy sputum may occur.

4. Sudden death

It accounts for 10% to 20%. In most cases, recurrent angina or syncope occurs before sudden death, but it can also be the first symptom. The cause may be related to severe and fatal arrhythmias, such as ventricular fibrillation.

5. Sweating and palpitations

These patients are particularly sweaty. Due to increased myocardial contraction and arrhythmia, patients often feel palpitations. Hyperhidrosis often occurs after palpitations, which may be related to autonomic nervous dysfunction and increased sympathetic tone.

Aortic stenosis

1. X-ray inspection

The heart shadow is normal or the left ventricle is slightly enlarged, the left atrium may be slightly enlarged, and the ascending aortic root is usually narrowed and dilated. Aortic valve calcification can be seen in lateral perspective. There may be signs of pulmonary congestion in advanced stages.

2. ECG examination

Severe stenosis has left ventricular hypertrophy with secondary ST-T changes and left atrial enlargement. There can be atrioventricular block, indoor block (left bundle branch block or left anterior branch block), atrial fibrillation or ventricular arrhythmia.

3. Echocardiography

It is an important method to clearly diagnose and determine the degree of stenosis. M-type diagnosis is insensitive and lacks specificity. Two-dimensional echocardiography is sensitive, providing cardiac chamber size, left ventricular hypertrophy, and function.

4. Left heart catheterization

Cardiac catheterization should be performed when sonocardiography cannot determine the degree of stenosis and consider prosthetic valve replacement. The most commonly used method is to simultaneously measure the left ventricle and aortic pressure through a left heart double-lumen catheter, or use a single-lumen catheter to slowly withdraw from the left ventricle to the aorta to continuously record the pressure curve; for example, the left heart catheter is difficult to pass through a narrow aortic valve The mouth can take the right heart catheter through the right ventricular puncture ventricular septum into the left ventricle and the aortic catheter synchronous pressure measurement. Calculate the left ventricle-aortic systolic peak pressure difference, and the valve area can be calculated based on the obtained pressure difference. > 1.0cm ² is slightly narrow, 0.75 1.0cm ² is moderate stenosis, and <0.75CM ^{2 is} severe stenosis. For example, if the pressure difference is judged, severe stenosis is the average pressure difference> 50mmHg or the peak pressure difference reaches 70mmHg.

Aortic stenosis diagnosis

According to the clinical symptoms, examination of the ejection systolic murmur of the aortic valve area at the bottom of the heart, and echocardiographic examination confirmed that the aortic valve stenosis can be clearly diagnosed.

Aortic valve stenosis treatment

1. Mild stenosis is asymptomatic and requires no treatment, but requires periodic review

If symptoms such as syncope, angina pectoris, left ventricular dysfunction occur, severe stenosis is considered, and the medical treatment effect is not obvious, which requires intervention or surgery.

Aortic valvuloplasty

The main indications are congenital aortic stenosis in children and young people; patients with severe aortic stenosis cannot tolerate cardiogenic shock; severe stenosis is life-threatening, and transitional treatment measures are risky due to heart failure surgery; Pregnant women with severe aortic stenosis; Those with severe aortic stenosis who refuse surgery.

3. Valve replacement therapy

Aortic valve disease technology is very mature, the success rate of surgery is more than 98%, and the effect is good. The main indications are: history of syncope or angina; left ventricular hypertrophy on electrocardiogram; cardiac function III-; pressure difference between left ventricle and aorta> 6.65kPa (50mmHg).