All patients, incl. with asymptomatic, fully compensated aortic stenosis, should be carefully monitored by a cardiologist. They are recommended to have an echocardiogram every 6-12 months. In order to prevent infective endocarditis, this contingent of patients requires preventive antibiotics before dental treatment (caries treatment, tooth extraction, etc.) and other invasive procedures.
Pregnancy management in women with aortic stenosis requires careful monitoring of hemodynamic parameters. An indication for abortion is severe aortic stenosis or an increase in signs of heart failure.
Drug therapy for aortic stenosis is aimed at eliminating arrhythmias, preventing coronary artery disease, normalizing blood pressure, slowing the progression of heart failure.
Radical surgical correction of aortic stenosis is shown at the first clinical manifestations of the defect – the appearance of shortness of breath, anginal pain, syncopal conditions. For this purpose balloon valvuloplasty can be used – endovascular balloon dilatation of aortic stenosis.
However, this procedure is often ineffective and is accompanied by subsequent recurrent stenosis. For non-coarse changes in the aortic valve cusps (more often in children with congenital defects), open surgical aortic valve repair (valvuloplasty) is used. In pediatric cardiac surgery, Ross’s operation is often performed, involving the transplantation of a pulmonary valve to the aortic position.
With appropriate indications resorted to the plastic nadklapannogo or podklapannaaaortic stenosis. The main method of treatment of aortic stenosis today is prosthetic aortic valve, in which the affected valve is completely removed and replaced with a mechanical analogue or xenogenous bioprosthesis. Patients with an artificial valve require lifelong intake of anticoagulants. In recent years, percutaneous aortic valve replacement has been practiced.
Aortic stenosis or aortic stenosis is characterized by a narrowing of the outflow tract in the area of the aortic lunar valve, making it difficult to systolic emptying of the left ventricle and the pressure gradient between its chamber and the aorta sharply increases. The share of aortic stenosis in the structure of other heart defects accounts for 20–25%. Aortic stenosis is 3–4 times more often detected in men than in women. Isolated aortic stenosis in cardiology is rare – in 1.5-2% of cases; in most cases, this defect is combined with other valvular defects – mitral stenosis, aortic insufficiency, etc.
Aortic stenosis is a narrowing of the aortic orifice in the valve area, which hampers the outflow of blood from the left ventricle. Aortic stenosis in the stage of decompensation is manifested by dizziness, fainting, fatigue, shortness of breath, attacks of stenocardia and suffocation. In the process of diagnosis of aortic stenosis, ECG, echocardiography, X-ray, ventriculography, aortography, cardiac catheterization are taken into account. In aortic stenosis, balloon valvuloplasty, aortic valve replacement, are resorted to; the possibilities of conservative treatment for this defect are very limited.
Classification of aortic stenosis
By origin distinguish congenital (3-5,5%) and acquired stenosis of the aortic mouth. Given the localization of pathological narrowing, aortic stenosis can be subvalvular (25–30%), supravalvular (6–10%) and valvular (about 60%).
The severity of aortic stenosis is determined by the gradient of systolic pressure between the aorta and the left ventricle, as well as the area of the valve opening.
With a minor aortic stenosis of I degree, the orifice area is from 1.6 to 1.2 cm² (at a rate of 2.5-3.5 cm²); the systolic pressure gradient is in the range of 10–35 mm Hg. Art. Moderate aortic stenosis of the II degree is indicated when the area of the valve hole is from 1.2 to 0.75 cm² and the pressure gradient is 36–65 mmHg. Art. Severe aortic stenosis of the III degree is observed when the area of the valve opening is less than 0.74 cm² and the pressure gradient increases to over 65 mm Hg. Art.
Depending on the degree of hemodynamic disturbances, aortic stenosis can occur according to a compensated or decompensated (critical) clinical variant, in connection with which 5 stages are distinguished.
- Stage I (full compensation). Aortic stenosis can only be detected by auscultatory, the degree of narrowing of the aortic mouth is negligible. Patients need dynamic monitoring by a cardiologist ; surgical treatment is not indicated.
- Stage II (latent heart failure ). There are complaints of fatigue, shortness of breath with moderate exertion, dizziness. Signs of aortic stenosis are determined according to ECG and X-ray, a pressure gradient in the range of 36–65 mm Hg. Art., which serves as an indication for surgical correction of the defect.
- Stage III (relative coronary insufficiency). Typically increased shortness of breath, the occurrence of angina, fainting. The gradient of systolic pressure exceeds 65 mm Hg. Art. Surgical treatment of aortic stenosis at this stage is possible and necessary.
- Stage IV (severe heart failure). Disturbed by shortness of breath at rest, nightly attacks of cardiac asthma. Surgical correction of the defect in most cases is already excluded; in some patients, cardiac surgery is potentially possible, but with less effect.
- V stage (terminal). Cardiac insufficiency progresses steadily, shortness of breath and edematous syndrome are expressed. Drug treatment can only achieve short-term improvement; surgical correction of aortic stenosis is contraindicated.
Causes of aortic stenosis
Acquired aortic stenosis is most often caused by rheumatic lesions of the valve leaflets. In this case, the valve flaps are deformed, spliced together, become dense and rigid, leading to a narrowing of the valve ring.
Causes of acquired stenosis of the aortic orifice can also include aortic atherosclerosis, calcification of the aortic valve, infective endocarditis, Paget’s disease, systemic lupus erythematosus, rheumatoid arthritis, and end-stage renal failure.
Congenital aortic stenosis occurs with congenital narrowing of the aortic or developmental abnormalities – the bicuspid aortic valve. Congenital aortic valve disease usually occurs before the age of 30; acquired – at a later age (usually after 60 years). Accelerate the formation of aortic stenosis, smoking, hypercholesterolemia, arterial hypertension.
Hemodynamic disorders in aortic stenosis
In aortic stenosis, gross intracardiac and then general hemodynamic disorders develop. This is due to the difficulty of emptying the left ventricular cavity, due to which there is a significant increase in the systolic pressure gradient between the left ventricle and the aorta, which can reach from 20 to 100 mm mm or more. Art.
The functioning of the left ventricle under conditions of increased load is accompanied by its hypertrophy, the degree of which, in turn, depends on the severity of the narrowing of the aortic orifice and the lifetime of the defect. Compensatory hypertrophy ensures long-term preservation of normal cardiac output, which hinders the development of cardiac decompensation.
However, in aortic stenosis, a disturbance of coronary perfusion occurs early enough due to an increase in the end-diastolic pressure in the left ventricle and compression of the subendocardial vessels by the hypertrophied myocardium. That is why patients with aortic stenosis show signs of coronary insufficiency long before the onset of cardiac decompensation.
As the contractile ability of a hypertrophied left ventricle decreases, the magnitude of the stroke volume and ejection fraction decreases, which is accompanied by myogenic left ventricular dilatation, increased end-diastolic pressure and development of left ventricular systolic dysfunction. Against this background, the pressure in the left atrium and the pulmonary circulation increases, i.e. arterial pulmonary hypertension develops.
At the same time, the clinical picture of aortic stenosis can be aggravated by relative insufficiency of the mitral valve (“mitralization” of aortic defect). High pressure in the pulmonary artery system naturally leads to compensatory hypertrophy of the right ventricle, and then to total heart failure.
Symptoms of aortic stenosis
At the stage of complete compensation of aortic stenosis, patients do not feel noticeable discomfort for a long time. The first manifestations are associated with a narrowing of the mouth of the aorta to approximately 50% of its lumen and are characterized by shortness of breath during physical exertion, fatigue, muscle weakness, feeling of palpitations.
At the stage of coronary insufficiency, dizziness, fainting with a rapid change in body position, attacks of angina pectoris, paroxysmal (night) shortness of breath, in severe cases – attacks of cardiac asthma and pulmonary edema join. Prognostically unfavorable combination of angina with syncopal states, and especially – the accession of cardiac asthma.
With the development of right ventricular insufficiency, edema, a feeling of heaviness in the right hypochondrium are noted. Sudden cardiac death in aortic stenosis occurs in 5-10% of cases, mainly in the elderly with severe narrowing of the valve orifice.
Complications of aortic stenosis can be infective endocarditis, cerebral ischemic disorders, arrhythmias, AV blockade, myocardial infarction, gastrointestinal bleeding from the lower digestive tract.
Diagnostics of aortic stenosis
The appearance of a patient with aortic stenosis is characterized by pallor of the skin (aortic pallor), due to a tendency to peripheral vasoconstrictor reactions; in the later stages acrocyanosis may occur. Peripheral edema is detected in severe aortic stenosis. When percussion is determined by the expansion of the borders of the heart to the left and down; palpation there is a displacement of the apical impulse, systolic tremor in the jugular fossa.
Auscultational signs of aortic stenosis are gross systolic murmur above the aorta and over the mitral valve, muffling of I and II tones on the aorta. These changes are also recorded during phonocardiography. According to ECG, signs of left ventricular hypertrophy, arrhythmias, and sometimes blockades are determined.
In the period of decompensation on radiographs, the expansion of the left ventricular shadow is revealed in the form of lengthening the arc of the left contour of the heart, the characteristic aortic configuration of the heart, poststenotic dilatation of the aorta, signs of pulmonary hypertension. On echocardiography is determined by the thickening of the aortic valve valves, limiting the amplitude of movement of the valve leaflets in systole, hypertrophy of the walls of the left ventricle.
In order to measure the pressure gradient between the left ventricle and the aorta, heart cavities are probed, which allows you to indirectly judge the degree of aortic stenosis. Ventriculography is necessary to detect concomitant mitral insufficiency. Aortography and coronary angiography are used for the differential diagnosis of aortic stenosis with aneurysm of the ascending aorta and coronary artery disease.
Prognosis and prevention of aortic stenosis
Aortic stenosis may be asymptomatic for many years. The appearance of clinical symptoms significantly increases the risk of complications and mortality.
The main, prognostically significant symptoms are angina, fainting, left ventricular failure – in this case, the average life expectancy does not exceed 2-5 years. With timely surgical treatment of aortic stenosis, 5-year survival is about 85%, 10-year – about 70%.
Measures to prevent aortic stenosis are reduced to the prevention of rheumatism, atherosclerosis, infectious endocarditis, and other contributing factors. Patients with aortic stenosis are subject to clinical examination and observation of a cardiologist and a rheumatologist.