Mitral stenosis

Description:

Mitral stenosis - the narrowing of a mitral orifice interfering a blood flow from the left auricle in a left ventricle. The most frequent reason - rheumatic fever.

Reasons of a mitral stenosis:

The mitral stenosis almost always happens a consequence of rheumatism. In North America and Western Europe the mitral stenosis occurs generally at the elderly people who had rheumatism in the childhood. In the rest of the world, including in Russia, rheumatism is eurysynusic, and the mitral stenosis is found in adults and teenagers, and sometimes even in children. If rheumatism is the reason of a mitral stenosis, shutters of the mitral valve partially grow together.

The mitral stenosis can be inborn. The babies born with this defect seldom live up to 2 years without operative measure. The myxoma (a benign tumor) located in the left auricle, or blood clot can complicate a blood flow through a mitral orifice, having the same effect, as narrowing of an opening of the mitral valve.

Mitral stenosis of a rheumatic origin it is possible to warn only by prevention of rheumatism - a disease of children's age which sometimes arises as a complication of not treated streptococcal quinsy.

Symptoms of a mitral stenosis:

About 2/3 patients point to the rheumatic attacks in the past. If defect is small and there are no excessive loadings, then the health can remain many years satisfactory. In typical cases the early complaint is an asthma at rise uphill. In more hard cases an asthma is provoked by any loading, excitement, fever and other factors which are speeding up a rhythm. Attacks of cardiac asthma can arise also in a prone position, at night. Heartbeat, cough, a pneumorrhagia, pains and weight in a breast are possible. Reduction of cordial emission can lead to dizziness and a faint. Outward of the patient usually does not change, and only at a heavy mitral stenosis peripheral cyanosis, a tsianotichesky flush, a pulsation of precordial and epigastric area owing to increase in a right ventricle are noticeable. Pulse and ABP remain normal or tendency to tachycardia and hypotension is noted. Later atrial fibrillation develops (paroxysmal or resistant). For early diagnosis the auskultativny picture, echocardiographic data, change of a configuration of heart have crucial importance.


The changes revealed at auscultation usually precede all other symptomatology. In typical cases over a top (clapping) loud I tone and abrupt tone (click) of opening of the mitral valve at the beginning of a diastole is listened. The low-frequency diastolic noise beginning after a mitral click with protodiastolic and presystolic strengthening is most characteristic. Only protodiastolic and presystolic noise, sometimes - only presystolic are in certain cases heard. Presystolic strengthening is not expressed at atrial fibrillation and sometimes during the period preceding blinking. Noise can be followed by the local palpated trembling of a chest wall. A combination of presystolic noise and a mitral click of a patognomonichna for a rheumatic mitral stenosis. At a part of patients also systolic noise which can be caused or mitral insufficiency, or, especially at significant increase in a right ventricle, by relative tricuspid insufficiency is listened.

All sound symptomatology, as well as trembling, come to light in position of the patient on the left side, at a little speeded up rhythm, for example after small loading, at breath holding on a full exhalation better. Expressiveness of sound symptomatology depends on many factors and not always reflects weight of defect. Over a pulmonary artery reveal accent and sometimes splitting of the II tone that is connected with a hypertension of a small circle. In late stages the independent soft protodiastolic noise caused by relative insufficiency of the valve of a pulmonary artery can be listened in the same place. The phonocardiography confirms auskultativny data. On the phonocardiogram removed from a top intervals between the beginning of the II tone and the beginning of a mitral click, and also between the beginning of a tooth Q ECGs and the beginning of the I tone can be measured. In process of increase in pressure in the left auricle the first interval decreases, the second increases.
ЭхоКГ easily confirms existence of a mitral stenosis and gives the chance to judge its expressiveness. She allows to specify structure of the valve (fibrosis, calcification) and features of the movement of shutters: during a diastole they are displaced concordantly, but is not discordant as is normal. On эхоКГ it is possible to determine the sizes of cardial cavities and sometimes to reveal pristenochny blood clots.

Change of a configuration of heart is found at X-ray inspection in a straight line and slanting projections with contrasting of a gullet. At a small mitral stenosis the silhouette of heart can be not changed. In process of progressing of defect increase in the left auricle comes to light that leads to straightening of the left contour of heart (smoothing of a waist) and then to its protrusion. In the right slanting projection the gullet pushing off back on an arch of small radius is visible. The shadow of a pulmonary artery extends. At far come disease increase and the right departments of heart, large pulmonary vessels and an upper vena cava comes to light. At raying kaltsinata in moving shutters of the mitral valve are sometimes noticeable.

On an ECG signs of an overload of the left auricle (a wide two-humped tooth P, especially in I and II assignments) and a right ventricle (increase in a tooth of R, decrease in a segment of ST, negative teeth of T in the right chest assignments), sometimes with development of an incomplete or total block of the right leg of a ventriculonector can be noticeable. Considerable deformation and expansion of a tooth P allow to predict fast approach of atrial fibrillation.

Diagnosis:

The preliminary diagnosis is made clinically and confirmed by means of an echocardiography. The two-dimensional echocardiography allows to obtain information on degree of valve calcification, the sizes of the left auricle and a stenosis. The Doppler echocardiography gives information on a chresklapanny gradient and pressure of a pulmonary artery. The transesophageal echocardiography can be used for detection or an exception of small blood clots in left predserdy, especially in its ear which cannot often be revealed at a transthoracic research.
The thorax X-ray analysis usually shows smoothing of the left border of heart because of an expanded ear of the left auricle. The main trunk of a pulmonary artery can be visible; diameter of the descending right pulmonary artery exceeds 16 mm if pulmonary hypertensia is expressed. Pulmonary veins of upper shares can be expanded as veins of the lower shares are squeezed that causes a plethora of upper shares. The double shadow of the increased left auricle can be determined by the right contour of heart. Horizontal lines in the lower back pulmonary fields (Kerli's line) specify on interstitial the hypostasis connected with high pressure in the left auricle.
Catheterization of heart is appointed only for preoperative identification of an ischemic heart disease: it is possible to estimate increase in the left auricle, pressure in pulmonary arteries and the area of the valve.
The ECG of the patient is characterized by emergence R-mitrale (wide, with PQ jag), a deviation of an electrical axis of heart to the right, especially at development of pulmonary hypertensia, and also a hypertrophy right (at the isolated mitral stenosis) and left (at a combination to mitral insufficiency) ventricles.
Weight of a stenosis is estimated by means of a Doppler research. The average transmitralpy pressure gradient and the area of the mitral valve can be rather precisely determined by the continuous and wave equipment. Assessment of degree of pulmonary hypertensia, and also the accompanying mitral and aortal regurgitation is of great importance.
It is possible to obtain additional information by means of a loading test (stress echocardiography) with registration of a transmitral and tricuspid blood-groove. At the area of the mitral valve < 1,5 см2 и градиенте давления >of 50 mm Hg (after loading) it is necessary to consider a question of carrying out balloon mitral valvuloplasty.
Besides, the spontaneous ekhokontrastirovaniye when carrying out a transesophageal echocardiography is an independent predictor of embolic complications at patients with a mitral stenosis.
The transesophageal echocardiography allows to specify existence or absence of blood clot of the left auricle, to specify degree of mitral regurgitation at the planned balloon mitral valvuloplasty. Besides, the chreegshshevodny research allows to estimate precisely a condition of the valve device and expressiveness of changes of subvalvular structures, and also to estimate probability of a restenosis.
Catheterization of heart and the main vessels is carried out when surgical intervention is planned, and data of noninvasive tests do not yield unambiguous result. The transseptal catheterization connected with unjustified risk is necessary for direct measurement of pressure in the left auricle and a left ventricle. As an indirect method of measurement of pressure in the left auricle serves determination of pressure of jamming of a pulmonary artery.

Treatment of a mitral stenosis:

Patients have to be under observation of the cardiorheumatologist, in cases of development of complications they need to be hospitalized. Patients with the isolated or prevailing mitral stenosis which is followed by an asthma without symptoms of the current rheumatism, without significant increase in heart it is necessary to direct to the cardiosurgeon together with whom the issue of expediency of operations (a mitral commissurotomy or valvuloplasty) is resolved. Medicinal treatment is carried out at emergence of complications and for prevention of a recurrence of rheumatism. If atrial fibrillation is observed at the patient to whom operation is not shown, recovery of a sinoatrial rate is not made, as a rule, (except for exceptional cases when blinking is an early complication). At takhisistologichesky blinking apply digoxin, antiagregant are usually necessary. Sinus tachycardia at a mitral stenosis is not the indication to use of cardiac glycosides.