Mitralny stenosis – the narrowing of the area of the left atrioventricular mouth leading to difficulty of physiological current of blood from the left auricle in the left ventricle. Clinically mitralny stenosis is shown by increased fatigue, interruptions in work of heart, short wind, cough with a blood spitting, discomfort in a breast. For identification of a mitralny stenosis auskultativny diagnostics, a X-ray analysis, an echocardiography, an electrocardiography, a phonocardiography, a kateterization of cameras of heart, atrio-and a ventrikulografiya is carried out. At the expressed stenosis the balloon valvuloplastika or a mitralny komissurotomiya is shown.
Mitralny stenosis – the acquired heart disease which is characterized by narrowing of the left predserdno-ventricular opening. In cardiology the mitralny stenosis is diagnosed for 0,05–0,08% of the population. The Mitralny stenosis can be isolated (40% of cases), to be combined with a nedostayotochnost of the mitralny valve (the combined mitralny defect) or with damage of other heart valves (mitralno-aortal defect, mitralno-trikuspidalny defect). The Mitralny stenosis 2-3 times more often is found in women, mainly at the age of 40-60 years.
Reasons of a mitralny stenosis
In 80% of cases the mitralny stenosis has a rheumatic etiology. The rheumatism debut, as a rule, occurs aged up to 20 years, and clinically expressed mitralny stenosis develops in 10–30 years. Among less common causes leading to a mitralny stenosis the infectious endocarditis, atherosclerosis, syphilis, heart injuries are noted.
Exceptional cases of a mitralny stenosis of not rheumatic nature can be connected with a heavy kaltsinoz of a ring and shutters of the mitralny valve, miksomy the left auricle, congenital heart diseases (Lyutembashe's syndrome), intracardial blood clots. Development of a mitralny restenoz after a komissurotomiya or prosthetics of the mitralny valve is possible. Aortal insufficiency can be followed by development of a relative mitralny stenosis.
Features of haemo dynamics at a mitralny stenosis
Normal the area of a mitralny opening makes 4-6 sq. cm, and its narrowing to 2 sq. cm and less is followed by emergence of violations of intracardial haemo dynamics. Stenozirovany an atrioventricular opening interferes a blood izgnayoniya from the left auricle in a ventricle. In these conditions compensatory mechanisms turn on: pressure in a cavity of an auricle increases from 5 to 20-25 mm of mercury., there is a lengthening of a systole of the left auricle, the hypertrophy of a myocardium of the left auricle develops that in total facilitates passing of blood through a stenozirovanny mitralny opening. These mechanisms at first allow to compensate influence of a mitralny stenosis on intracardial haemo dynamics.
However further progressing of a mitralny stenosis and growth of a transmitralny gardiyent of pressure is followed by retrograde increase in pressure in system of pulmonary vessels, leading to development of pulmonary hypertensia. In the conditions of considerable rise in pressure in a pulmonary artery load of the right ventricle increases and depletion of the right auricle is at a loss that causes a hypertrophy of the right departments of heart.
Owing to need of overcoming considerable resistance for a pulmonary artery and development of sklerotichesyoky and dystrophic changes of a myocardium sokratitelny function of the right ventricle decreases and there is its dilatation. At the same time load of the right auricle increases that finally brings into blood circulation decompensations on a big circle.
Classification of a mitralny stenosis
On the area of narrowing of the left atrioventricular opening allocate 4 degrees of a mitralny stenosis:
- The I degree – an insignificant mitralny stenosis (the area of an opening> of 3 sq. cm)
- The II degree - a moderate mitralny stenosis (the area of an opening of 2,3-2,9 sq. cm)
- The III degree - the expressed mitralny stenosis (the area of an opening of 1,7-2,2 sq. cm)
- The IV degree - a critical mitralny stenosis (the area of an opening of 1,0-1,6 sq. cm)
According to progressing of haemo dynamic frustration the current of a mitralny stenosis passes 5 stages:
- I – stage of full compensation of a mitralny stenosis left auricle. Subjective complaints are absent, however direct signs of a stenosis auskultativno come to light.
- II - a stage of violations of blood circulation in a small circle. Subjective symptoms arise only at physical activity.
- III – a stage of the expressed stagnation signs in a small circle and initial signs of violation of blood circulation in a big circle.
- IV - a stage of the expressed stagnation signs in a small and big circle of blood circulation. At patients vibrating arrhythmia develops.
- V – the dystrophic stage, corresponds to the III stage of heart failure
Symptoms of a mitralny stenosis
Clinical signs of a mitralny stenosis, as a rule, arise at the area of an atrioventricular opening less than 2 quarter see. Increased fatigue, short wind at physical effort is noted, and then and at rest, cough with allocation a blood streak in a phlegm, tachycardia, violation of a rhythm of heart as premature ventricular contraction and vibrating arrhythmia. At the expressed mitralny stenosis arises , night attacks of cardiac asthma, in more hard cases - hypostasis of lungs.
In case of a considerable hypertrophy of the left auricle there can be a sdavleniye of a returnable nerve to development of a dysphonia. About 10% of patients with a mitralny stenosis show complaints to the heartaches which are not connected with physical activity. At the accompanying coronary atherosclerosis, subendokardialny ischemia stenocardia attacks are possible. Patients often have repeated bronchitis, bronchial pneumonia, krupozny pneumonia. At a combination of a mitralny stenosis to mitralny insufficiency the bacterial endocarditis often joins.
Appearance of patients with a mitralny stenosis is characterized by cyanosis of lips, a tip of a nose and nails, existence of limited crimson and cyanotic coloring of cheeks ("a mitralny flush" or "a doll flush"). The hypertrophy and dilatation of the right ventricle quite often cause development of a warm hump.
In process of development of right ventricular insufficiency weight in a stomach, a geptomegaliya, peripheral hypostases, swelling of cervical veins, dropsy of cavities appears (right-hand , ascites). As the main reason for a lethal outcome at a mitralny stenosis serves the thrombembolia of a pulmonary artery.
Diagnostics of a mitralny stenosis
When collecting data on development of a disease the rheumatic anamnesis manages to be tracked at 50–60% of patients with a mitralny stenosis. The palpation of nadserdechny area reveals so-called "cat's purring" - presistolichesky trembling, perkutorno borders of heart are displaced up and to the right. The Auskultativny picture of a mitralny stenosis is characterized by the clapping I tone and tone of opening of the mitralny valve ("mitralny click"), existence of diastolic noise. The phonocardiography allows to correlate the listened noise to this or that phase of a warm cycle.
The electrocardiographic research (ECG) at a mitralny stenosis reveals a hypertrophy of the left auricle and the right ventricle, violation of a warm rhythm (vibrating arrhythmia, premature ventricular contraction, paroksizmalny tachycardia, trembling of auricles), blockade of the right leg of a bunch of Gis.
By means of an echocardiography it is possible to find reduction of the area of a mitralny opening, uplotneyony walls of the mitralny valve and a fibrous ring, increase in left its auricle. Chrespishchevodny EhoKG at a mitralny stenosis is necessary for an exception of vegetations and a kaltsinoz of the valve, existence of blood clots in the left auricle.
Data of radiological researches (a X-ray analysis of a thorax, a heart X-ray analysis with contrasting of a gullet) are characterized by a vybukhaniye of an arch of a pulmonary artery, the left auricle and the right ventricle, a mitralny configuration of heart, expansion of shadows of hollow veins, strengthening of the pulmonary drawing and other indirect signs of a mitralny stenosis.
When sounding cavities of heart elevated pressure in the left auricle and the right departments of heart, increase in a transmitralny gradient of pressure is found. The left ventrikulografiya and an atriografiya, and also a coronary angiography are shown to all applicants for prosthetics of the mitralny valve.
Treatment of a mitralny stenosis
Medicamentous therapy at a mitralny stenosis is necessary for the purpose of prevention of an infectious endocarditis (antibiotics), reduction of expressiveness of heart failure (warm glycosides, diuretics), knocking over of arrhythmias (beta-blockers). At tromboemboliya in the anamnesis hypodermic introduction of heparin under control of MNO, reception of antiagregant is appointed.
Pregnancy is not contraindicated to women with a mitralny stenosis in case the area of a mitralny opening makes more than 1,6 sq. cm and there are no signs of a warm decompensation; otherwise termination of pregnancy on medical indications is carried out.
Expeditious treatment of a mitralny stenosis is carried out at II, III, IV stages of violation of haemo dynamics. In the absence of deformation of shutters, calcification, damage of papillary muscles and chords performance of a balloon valvuloplastika is possible. In other cases the closed or open komissurotomiya during which solderings are cut is shown, shutters of the mitralny valve are exempted from kaltsifikat, blood clots from the left auricle are removed, the annuloplastika at mitralny insufficiency is made. Rough deformation of the valvate device is the basis for prosthetics of the mitralny valve.
Forecast and prevention of a mitralny stenosis
Five-year survival at the natural course of a mitralny stenosis makes 50%. Even the small asymptomatic mitralny stenosis is inclined to progressing owing to the repeated attacks of a revmokardit. The indicator of postoperative 5-year survival makes 85-95%. Postoperative develops approximately at 30% of patients within 10 years that demands carrying out a mitralny rekomissurotomiya.
Prevention of a mitralny stenosis consists in performing antirecurrent prevention of rheumatism, sanitation of the centers of a chronic streptococcal infection. Patients are subject to observation by the cardiologist and rheumatologist and passing of regular full kliniko-tool inspection for an exception of progressing of a mitralny stenosis.