Mitral valve disease: what it is, the main types and methods of treatment

Mitral valve structure

The left atrioventricular valve is a complex anatomical complex, which includes cusps, papillary muscles, tendon chords, as well as a connective tissue ring connecting the left atrium and the left ventricle. The leaflets of the mitral valve (anterior and posterior) consist of fibrous tissue, their surface is represented by an extension of the endocardium. Normally, these are two thin structures, therefore the mitral valve is also called bicuspid.

In the diastole phase, the valves sag down and blood from the left atrium enters the left ventricle. In the phase of systole, during contraction, they rise and close the left atrioventricular opening, thereby preventing the return of blood.

Types of violations and reasons for their occurrence

Mitral heart disease is a group of congenital or acquired anomalies and defects of the valve apparatus located between the left atrium and the left ventricle, which disrupt intracardiac and general hemodynamics, which actually prevents an adequate blood supply to internal organs with the possible development of heart failure.

Causes of congenital heart defects:

• pathologies of pregnancy (infections, chronic diseases of the mother, taking medications, radiation);
• genetic disorders (chromosomal mutations);
• impaired differentiation of connective tissue.

The etiology of acquired mitral defects is:

• acute rheumatic fever - rheumatism (in 85% of cases);
• infective endocarditis;
• atherosclerosis;
• sepsis;
• systemic defects of connective tissue (scleroderma, rheumatoid arthritis with damage to internal organs).

Mitral valve disease (MVP) is:

• stenosis - narrowing of the left atrioventricular opening due to fusion of the bicuspid valve, which prevents normal blood flow from the left atrium to the ventricle;
• failure - incomplete closure of the mitral opening due to a defect in the valve and subvalvular structures, which is accompanied by regurgitation of blood from the left ventricle into the atrium.

Unfortunately, often in modern practice there is a combined mitral heart disease. With it, there is a combination of stenosis with insufficiency in various variants of the predominance of one defect over the other.

According to the severity, a defect of the first, second and third degree is distinguished. Their difference lies in the severity of reverse casting in case of insufficiency (or narrowing with stenosis), which determines the complexity of clinical manifestations (respectively, 1 degree is the mildest, 2 and 3 are more aggravated)

Combined mitral valve disease

Long-term damage to the structure of the mitral valve with restructuring of the muscular frame of the heart leads to the development of complex disorders.

Features of combined mitral disease:

stenosis: during atrial contraction, not all blood enters the ventricle due to the narrowed lumen;

failure (regurgitation): the valve flaps do not fully close during ventricular systole, and some of the blood enters the atrium;

the combination of the phenomena leads to the accumulation of fluid in the upper chamber, stretching of the wall and the development of heart failure with pulmonary edema.

The clinical characteristics of the disease are two pathological murmurs in the projection area of ​​the bicuspid valve, characteristic of both defects.

Rheumatic mitral disease

Acute rheumatic fever transferred in childhood is one of the main reasons for the development of valvular defects (most often mitral and aortic) in adults.

The mechanism of development of pathology is associated with streptococcal infection. After the pathogen enters the body, an immune response is developed with the production of specific antibodies (neutralizing proteins).

However, the antigenic structure of the bacterium in terms of protein structure is "similar" to the endocardial tissue, therefore the action of antibodies is aimed at destroying not only the infectious pathogen, but also the own tissues of the heart valve apparatus.

Symptoms, signs and main complaints of patients

The clinical picture of the disease depends on the type of defect itself, the degree of intracardiac and systemic hemodynamic disturbances, the duration of the pathological process and the level of problems from other organs and systems.

In the stage of compensation, which proceeds without signs of heart failure, patients do not complain about their well-being and for a long time may not be in the field of vision of the doctor. And only with the development of decompensation, the following complaints and signs appear:

• shortness of breath - associated with an increase in pressure in the pulmonary circulation (ICC);
• hemoptysis - due to sweating of the blood elements with pronounced stagnation in the veins of the ICC;
• blunt cardialgia;
• interruptions in the work of the cardiac system - palpitations, arrhythmias, atrial fibrillation, extrasystoles.

Combined (not combined) mitral valve defect decompensates very quickly, as a result of which stagnation of blood in the systemic circulation is added to it, which clinically manifests itself as swelling of the cervical veins, heaviness in the right hypochondrium and enlargement of the liver (hepatomegaly), edema of the lower extremities.

Diagnostics

In order to diagnose any pathology of the mitral valve, it is necessary to assess the patient's complaints, survey data (possibly previously transferred rheumatic heart disease), objective examination (auscultation) and additional studies.

The appearance of a patient who has rheumatic mitral valve disease has the following symptoms:

• the typical patient has an asthenic constitution with undeveloped muscle mass and cold upper limbs;
• cyanosis of the lips, chin, nose, ears in combination with a bright bluish-pink blush on the cheeks and pallor around the eyes (due to vasodilation of the skin and prolonged hypoxemia).

The auscultatory picture of mitral defects is quite bright and a competent specialist who owns this method can easily suspect this pathology.

Results of instrumental examinations

Electrocardiography (ECG) helps to identify thickening or damage to the myocardium, to detect changes in the size of cavities, to verify arrhythmias.

Chest x-ray - important for the diagnosis of dilatation of the heart cavities and the severity of the lesion of the broncho-pulmonary tree.

However, echocardiography is the gold standard for detecting heart defects. The value of ultrasound examination is determined by the fact that it allows not only to reveal the degree of narrowing or expansion of the atrioventricular opening, to evaluate the anatomy of the valves themselves, but also gives data on the intracardiac circulation.

Patient treatment and follow-up

The main goals of therapy for patients with mitral valve defects are to alleviate the general condition, increase the quality and duration of life.Today, the treatment is carried out in a comprehensive manner, including both medication and surgical procedures.

The following groups of drugs are recommended: β-blockers, ACE inhibitors, diuretics, nitrates, anticoagulants.

If there are indications for surgery, apply:

1. Percutaneous balloon valvuloplasty.
2. Open commissurotomy.
3. Valve replacement.

The specific individual treatment regimen and the type of surgical correction is determined only by a specialist, taking into account the type of defect, the degree of development, and the data of instrumental studies.

Of course, in the future, the patient should be constantly under the supervision of specialists, regularly undergo periodic examinations and carefully follow medical recommendations.

It is very important to carry out timely prevention of recurrence of rheumatism, which is carried out by lifelong use of benzylpenicillin.

Conclusions

Mitral valve pathology can occur in people of any age and often leads to the development of formidable complications, up to and including death. Timely detection of this pathology followed by adequate modern treatment can significantly increase the life expectancy of patients and improve the prognosis for recovery.