Acquired heart disease: mitral stenosis

Narrowing of the opening between the left chambers of the heart , known as mitral stenosis, is always organic. The main reason for the development of this acquired heart disease is rheumatic endocarditis. Mitral stenosis is much less common with endocarditis of other origin.

Narrowing of the atrioventricular aperture develops as a result of the fusion of the mitral valve flaps between themselves, their thickening and compaction. The valve takes the form of a diaphragm with a slit-shaped hole in the middle or a funnel shape.

The area of the mitral orifice is normally 4-6 sq. Km. See Mitral stenosis leads to a change in blood flow to the heart. Hemodynamic disturbances appear when the aperture is narrowed to 1.5 square meters. See During diastole, the blood from the left atrium does not have time to completely pass into the left ventricle. Therefore, in the left atrium is a small amount of blood, to which blood is added, coming from the pulmonary veins. As a result, the atrium is filled with blood, and the pressure increases in it, which is first compensated by increased contractions and atrial tension. But since the muscular wall of the atrium is weak, its contractility decreases soon, blood stagnation increases, and the pressure in it is further increased. With time, blood stagnation occurs in a small circle of blood circulation, an increase in the load on the right ventricle, stagnation occurs in the system of vessels of a large circle.

Clinical picture

If the stenosis is not stark, the patient may not have any complaints, physical activity is not necessarily limited. The first complaints, indicating the appearance of stagnation in the vessels of the small circle of blood circulation, are shortness of breath and cough - dry or with a small amount of sputum, as well as increased fatigue and palpitations. Later hemoptysis and periodic attacks of cardiac asthma appear . Pain in the heart appears in about 10% of patients.

Pulse may not be the same on both hands. This is because the enlarged left atrium squeezes the left subclavian artery, and the filling of the pulse on the left decreases. Atrial fibrillation often occurs.

Palpation above the tip of the heart is determined by the symptom of cat purring. There is a cat purring while passing blood through a modified mitral orifice.

Percussion is determined by the displacement of the boundaries of the heart up and to the right, which occurs as a result of changes in individual chambers of the heart, which receives a mitral configuration.

Auscultation of the heart is of great importance in the diagnosis of malformation, since mitral stenosis has a characteristic auscultative melody. Above the top of the heart is a ringing clapping first tone, diastolic noise and an additional tone formed when the mitral valve is opened. All this forms a typical auscultative melody, called the rhythm of the quail. On the basis of the heart, accent and bifurcation are heard, or the splitting of the second tone, the appearance of which is associated with the stagnation of blood in the lungs.

Arterial pressure, as a rule, does not change, sometimes systolic decreases slightly and diastolic increases.

Instrumental diagnostics

On the roentgenogram the changed configuration of the heart, called mitral, and stagnant phenomena is determined.

On ECG - signs of an increase in the chambers of the heart.

FKG data repeat the results of auscultation of the heart.

Of great importance in the diagnosis of defects is echocardiography, which allows to determine the deformation of the valve, the thickening and calcification of its valves, the change in the volume of the chambers of the heart, and the thickness of the heart wall.

Treatment

Treatment of stenosis of any site requires an operative intervention. With stenosis of valves, the operation consists in performing commissurotomy - dissection of the modified valve flaps. Mitral and aortic stenosis, the treatment of which is performed surgically, before the operation must be translated into a compensated stage.