How does narrowing develop?
The aortic valve leaflets gradually thicken, calcium is deposited in them, and mobility decreases. The process resembles not simple wear and tear, but active inflammation and tissue restructuring associated with the same factors as atherosclerosis. The left ventricle compensates for the obstacle by thickening the wall: it copes for a long time, so the person does not feel the disease. But a thickened muscle relaxes less well and is less well supplied with blood, and during exercise there is a lack of oxygen. When compensation is depleted, shortness of breath and heart failure quickly increase.
- Calcium deposition and thickening of the valves
- Decreased valve mobility
- Thickening of the wall of the left ventricle
- Impaired blood supply to the thickened muscle
- Gradual depletion of compensation
Causes and risk factors
In older people, the leading cause is age-related degenerative valve calcification. In patients younger than 60–65 years, a common finding is a congenital bicuspid aortic valve: it wears out faster than the tricuspid and leads to stenosis several decades earlier. A separate group consists of rheumatic defects, which are usually combined with damage to the mitral valve. The rate of progression is higher with hypertension, lipid metabolism disorders, smoking and chronic kidney disease.
- Age-related calcification of the valves
- Congenital bicuspid aortic valve
- Rheumatic heart disease
- Arterial hypertension
- Lipid disorders and smoking
- Chronic kidney disease, calcium metabolism disorders
Symptoms
The classic triad appears late and means that it is time to decide on surgery. Shortness of breath first occurs with significant exertion, then with normal walking. Angina pectoris is manifested by compressive pain behind the sternum when moving, which goes away with rest, and the coronary arteries may be clear. Fainting usually occurs at a height of exertion, when the blood vessels dilate and the heart cannot increase blood output. In older people, the first signs are decreased tolerance for usual activities and fatigue, which are mistakenly attributed to age.
- Shortness of breath on exertion and later at rest
- Tightening chest pain when walking
- Dizziness and fainting on exertion
- A sharp decrease in endurance
- Heart palpitations and interruptions
- Swelling of the legs in later stages
Diagnostics
The doctor hears a characteristic rough noise, carried out on the vessels of the neck, and a weakening of tones. The diagnosis and severity are clarified by echocardiography: the speed of blood flow through the valve, pressure drop and orifice area are measured, and the wall thickness and ventricular function are assessed. ECG shows left ventricular overload. For asymptomatic severe stenosis, supervised stress testing and natriuretic peptide testing are used to determine whether the person is truly asymptomatic. Before the intervention, a CT scan and evaluation of the coronary arteries are performed.
- Auscultation and pressure measurement
- EchoCG with assessment of gradient and orifice area
- ECG
- NT-proBNP
- Stress test for asymptomatic severe stenosis
- CT scan of the heart and blood vessels before surgery
- Assessment of the condition of the coronary arteries
Treatment
There are no drugs that dissolve calcium on the valves, so drugs only control pressure, rhythm and concomitant diseases. For asymptomatic non-severe stenosis, observation with repeated echocardiography is prescribed, the frequency of which depends on the degree of narrowing. If symptoms occur or ventricular function decreases, valve replacement is indicated. There are two main options: open surgery with prosthetics and transcatheter valve implantation through the vessel, which is increasingly being chosen for the elderly and patients at high surgical risk. The decision is made by a team of cardiologist and cardiac surgeon, taking into account age, anatomy and concomitant diseases.
- Regular monitoring and repeat echocardiography
- Control of blood pressure, lipids, sugar, smoking cessation
- Aortic valve replacement
- Transcatheter valve implantation
- Caution with drugs that reduce blood pressure and blood volume
- Moderate activity, avoidance of sudden isometric loads
- Thorough sanitation of the oral cavity
