Aortic valve: structure, mechanism of operation. Stenosis and aortic valve insufficiency

Aortic heart disease is usually characterized by acquired character and manifested clinically only in the elderly. Their presence can cause severe hemodynamic disorders. The severity of the pathology is that changes affecting the valves are irreversible.

Heart structure: valves

The heart is a hollow organ, which consists of 4 chambers. The left and right halves are separated by septa, in which there are no formations, however, between the atrium and ventricle of each side there is an orifice provided with a valve. These formations allow you to regulate blood circulation, not allowing regurgitation, that is, reverse casting.

To the left is a mitral valve, consisting of two valves, and to the right is a tricuspid valve, it has three valves. The valves are equipped with tendon threads, which ensures their opening only in one direction. This prevents the return of blood to the atria. At the site of the left ventricle in the aorta there is aortal valve. Its function is to ensure unilateral advance of blood into the aorta. On the right side there is also a valve of the pulmonary artery. Both formations are called "semilunar", they have three leaves. Any pathology, for example, calcification of the valves of the aortic valve, leads to disruption of blood movement. Acquired defects are usually associated with a disease. Therefore, people who have so-called risk factors should undergo a regular examination: mainly an echocardiogram.

The mechanism of operation of the aortic valve

An important role in the circulation of the blood is played by the aortic valve. Valves are compacted or shortened - this is one of the main pathologies. It becomes the cause of hemodynamic disorders. The function of this part of the body is to ensure the progress of blood from the left atrium to the ventricle, preventing regurgitation. The valves are open during the atrial systole, at which time the blood is directed through the aortic valve into the ventricle. Further, the flaps are closed to prevent reverse casting.

Heart defects: classification

By the time of occurrence it is possible to distinguish congenital heart defects (aortic valve and other formations) and acquired ones. Changes affect not only the valves, but also the septa of the heart. Congenital pathologies are often combined, which makes diagnosis and treatment more difficult.

Stenosis of the aortic valve

Pathology involves narrowing the transition of the left ventricle into the aorta - the valves of the valve and surrounding tissues are affected. This disease, according to statistical indicators, is more common in men. Sealing of the walls of the aorta and aortic valve flaps is usually associated with rheumatic and degenerative lesions. Endocarditis, rheumatoid arthritis can also act as an etiological factor. These diseases lead to the fusion of the valves, as a result of which their mobility decreases, and the valve can not fully open during the systole of the left ventricle. In old age, the cause of the lesion is often atherosclerosis and calcification of the valves of the aortic valve.

As a result of narrowing of the aortic opening, significant changes in hemodynamics occur. They are observed when the stenosis has a pronounced degree - a decrease in the tract by more than 50%. This leads to the fact that the pressure gradient of the aortic valve varies - in the aorta, the pressure remains normal, and in the left ventricle it increases. Increased exposure to the wall of the left ventricle leads to the development of compensatory hypertrophy, that is, to its thickening. In the following, the diastolic function is violated, which is the reason for the increase in pressure in the left atrium. Hypertrophy leads to an increase in the need for oxygen, however, the increased blood mass of the myocardium is the former blood supply, and with accompanying pathologies even reduced. This leads to the development of heart failure.

Clinic

In the early stages, the affected aortic valve may not manifest itself. Clinical changes occur when the aperture is narrowed by 2/3 of the norm. With severe physical exertion, patients begin to worry about pain localized behind the sternum. Pain syndrome in rare cases can be combined with loss of consciousness due to systemic vasodilation. The formation of pulmonary hypertension leads to dyspnea, which first disturbs only when loaded, but then appears and at rest. The prolonged course of the disease causes chronic heart failure. Pathology requires surgical treatment, as there is a risk of deterioration and sudden cardiac death.

Diagnostics

When examined in patients, characteristic pallor associated with a decreased cardiac output is observed. The pulse on the radial arteries is palpable with difficulty - it is rare and weak. At auscultation there is a weakening of the tone or its splitting. ECG is not sufficiently informative - the signs of hypertrophy are determined only with a severe degree of stenosis. The most indicative is echocardiography, which makes it possible to evaluate the aortic valve. The valves are sealed and thickened, the hole is narrowed - these are the main diagnostic criteria that help to detect this study. Degree of stenosis and gradient of pressure effectively allows to determine the catheterization of cavities.

Treatment

With a mild and moderate degree of stenosis, only a correction of the lifestyle is required - avoidance of excessive physical exertion, treatment of concomitant pathologies. With increased frequency of contractions, adrenoblockers are prescribed, and in case of heart failure diuretics, cardiac glycosides are effective . The pronounced compaction of the walls of the aorta and the valves of the aortic valve requires surgical treatment. As a rule, prosthetics or balloon dilatation is performed.

Aortic valve insufficiency

Such a name was received by a pathology characterized by unobstructed wings. This phenomenon leads to a reverse transfer of blood into the left ventricle, which occurs during diastole. The vice is usually a complication of infective endocarditis and rheumatic damage. Less common are syphilis, aortic aneurysm, aortitis, arterial hypertension, Marfan syndrome, systemic lupus erythematosus.

The aortic valve plays an important role in the circulation. Incomplete closure of its valves becomes the cause of regurgitation, that is, the reverse transfer of blood into the left ventricle. As a result, there is an excessive volume of blood in its cavity, which leads to overload and stretching. The systolic function is broken, and the raised pressure conducts to development of a hypertrophy. Retrograde pressure in the small circle rises - pulmonary hypertension is formed.

Clinic

As with stenosis, pathology makes itself felt only with a pronounced degree of insufficiency. With physical exertion, shortness of breath occurs, it is associated with pulmonary hypertension. Pain concerns only in 20% of cases. At the same time expressed auscultative and external manifestations of pathology:

1. Ripple of carotid arteries.
2. Symptom Durozier or the occurrence of systolic murmur on the femoral artery. It occurs when it is pinched closer to the listening position.
3. Symptom Quincke is a change in the color of the lips and nails according to the pulsation of the arterioles.
4. Traube's double tones, loud, "cannon", which arise over the femoral artery.
5. Symptom de Musset, showing a wiggle of his head.
6. Diastolic murmur after 2 tones that occurs with auscultation of the heart, as well as a weakening of 1 tone.

Diagnostics

Informative methods are echocardiography and catheterization of cavities. They allow you to evaluate the aortic valve, and also to track the volume of regurgitated blood. Based on these studies, the degree of severity of the defect is determined and the question of the necessity of surgical intervention is solved.

Treatment

The expressed insufficiency with a large volume of regurgitation, intensive clinical manifestations requires surgical treatment. Optimal output - artificial aortic valves, which allow the restoration of the heart. If necessary, symptomatic medicinal therapy is prescribed.

Stenosis and insufficiency of the aortic valve are the most common heart defects, which, as a rule, are the outcome of any local or systemic disease. Pathology progresses slowly enough that it allows to diagnose it in time. Modern methods of treatment help restore the valve and improve the condition of the patient.