Aortal stenosis – the narrowing of an opening of an aorta in the field of the valve complicating outflow of blood from the left ventricle. The aortal stenosis in a stage of a decompensation is shown by dizziness, faints, bystry fatigue, short wind, attacks of stenocardia and suffocation. In the course of diagnostics of an aortal stenosis the given ECGs, an echocardiography, a X-ray analysis, a ventrikulografiya, an aortografiya, a heart kateterization are considered. At an aortal stenosis resort to a balloon valvuloplastika, prosthetics of the aortal valve; possibilities of conservative treatment at this defect are very limited.
The aortal stenosis or stenosis of the mouth of an aorta is characterized by narrowing of the taking-out path in the field of the semi-lunar valve of an aorta in this connection systolic depletion of the left ventricle is at a loss and sharply pressure gradient between its camera and an aorta increases. 20–25% fall to the share of an aortal stenosis in structure of other heart diseases. The stenosis of the mouth of an aorta 3-4 times more often comes to light at men, than at women. The isolated aortal stenosis in cardiology meets seldom – in 1,5-2% of observations; in most cases this defect is combined with other valvate defects - a mitralny stenosis, aortal insufficiency, etc.
Classification of an aortal stenosis
By origin distinguish congenital (3-5,5%) and the acquired stenosis of the mouth of an aorta. Taking into account localization of pathological narrowing the aortal stenosis can be subvalvate (25-30%), nadklapanny (6-10%) and valvate (about 60%).
Degree of expressiveness of an aortal stenosis is determined by a gradient of systolic pressure between an aorta and the left ventricle, and also the areas of a valvate opening. At an insignificant aortal stenosis of the I degree the area of an opening makes from 1,6 to 1,2 cm ² (at norm of 2,5 — 3,5 cm ²); the gradient of systolic pressure is in limits of 10-35 mm of mercury. Tell about a moderate aortal stenosis of the II degree at the area of a valvate opening from 1,2 to 0,75 cm ² and a gradient of pressure of 36-65 mm of mercury. The heavy aortal stenosis of the III degree is noted when narrowing the area of a valvate opening less than 0,74 cm ² and increase in a gradient of pressure over 65 mm of mercury.
Depending on extent of haemo dynamic violations the aortal stenosis can proceed by the compensated or dekompensirovanny (critical) clinical option in this connection 5 stages are allocated.
I stage (full compensation). The aortal stenosis can be revealed only auskultativno, extent of narrowing of the mouth of an aorta is insignificant. Patients need dynamic observation of the cardiologist; surgical treatment is not shown.
II stage (latent heart failure). Complaints to bystry fatigue, short wind at moderate physical activity are shown, dizziness. Signs of an aortal stenosis are determined by data of the ECG and a X-ray analysis, pressure gradient in the range of 36-65 mm of mercury., what serves as the indication to surgical correction of defect.
III stage (relative coronary insufficiency). Strengthening of short wind, developing of stenocardia, faints is typical. The gradient of systolic pressure exceeds 65 mm of mercury. Surgical treatment of an aortal stenosis at this stage is possible and it is necessary.
The IV stage (the expressed heart failure). Short wind at rest, night attacks of cardiac asthma disturbs. Surgical correction of defect is in most cases already excluded; at some patients cardiac treatment is potentially possible, but with smaller effect.
V stage (terminal). Steadily heart failure progresses, short wind and an edematous syndrome are expressed. Drug treatment allows to achieve only short-term improvement; surgical correction of an aortal stenosis is contraindicated.
Reasons of an aortal stenosis
The acquired aortal stenosis most often is caused by rheumatic defeat of shutters of valves. At the same time gates of the valve are deformed, spliced among themselves, become dense and rigidny, leading to narrowing of a valvate ring. As the reasons of the acquired stenosis of the mouth of an aorta aorta atherosclerosis, (calcification) of the aortal valve, an infectious endocarditis, Pedzhet's disease, system red a wolf cub, rheumatoid arthritis, a terminal renal failure can also serve.
The congenital aortal stenosis is observed at congenital narrowing of the mouth of an aorta or anomaly of development - the two-fold aortal valve. Congenital defect of the aortal valve is usually shown aged up to 30 years; acquired – at more advanced age (usually after 60 years). Smoking, a hypercholesterolemia, arterial hypertension accelerate process of formation of an aortal stenosis.
Violations of haemo dynamics at an aortal stenosis
At an aortal stenosis gross violations of intracardial, and then and general haemo dynamics develop. It is connected with the complicated depletion of a cavity of the left ventricle in view of what there is a significant increase in a gradient of systolic pressure between the left ventricle and an aorta which can reach from 20 to 100 and more than a mm of mercury.
Functioning of the left ventricle in the conditions of the raised loading is followed by its hypertrophy which degree, in turn, depends on expressiveness of narrowing of an aortal opening and time of existence of defect. The compensatory hypertrophy provides long preservation of the normal warm emission constraining development of a warm decompensation.
However at an aortal stenosis early enough there comes the violation of coronary perfusion connected with increase in final diastolic pressure in the left ventricle and a sdavleniye a hypertrophied myocardium of subendokardialny vessels. For this reason at patients with an aortal stenosis signs of coronary insufficiency appear long before approach of a warm decompensation.
In process of decrease in sokratitelny ability of a hypertrophied left ventricle, the size of shock volume and fraction of emission decreases that is followed by miogenny left ventricular dilatation, increase in final diastolic pressure and development of systolic dysfunction of the left ventricle. On this background pressure in the left auricle and a small circle of blood circulation increases, i.e. arterial pulmonary hypertension develops. At the same time the clinical picture of an aortal stenosis can be aggravated with relative insufficiency of the mitralny valve ("mitralization" of aortal defect). High pressure in system of a pulmonary artery naturally leads to a compensatory hypertrophy of the right ventricle, and then and to total heart failure.
Symptoms of an aortal stenosis
At a stage of full compensation of an aortal stenosis patients a long time do not feel noticeable discomfort. The first manifestations are connected with narrowing of the mouth of an aorta approximately to 50% of its gleam and are characterized by short wind at physical activity, bystry fatigue, muscular weakness, feeling of serdtsebiyeniye.
At a stage of coronary insufficiency dizziness, faints at bystry change of position of a body join, stenocardia attacks, paroksizmalny (night) short wind, in hard cases - attacks of cardiac asthma and hypostasis of lungs. Predictively the stenocardia combination to sinkopalny states and especially – accession of cardiac asthma is adverse.
At development of right ventricular insufficiency hypostases, heavy feeling in the right podreberye are noted. Sudden warm death at an aortal stenosis comes in 5–10% of cases, mainly, at elderly people with the expressed narrowing of a valvate opening. The infectious endocarditis, ischemic violations of brain blood circulation, arrhythmia, AV-blockade, a myocardial infarction, gastrointestinal bleedings from the lower departments of a digestive tract can be complications of an aortal stenosis.
Diagnostics of an aortal stenosis
Appearance of the patient with an aortal stenosis is characterized by pallor of integuments ("aortal pallor") caused by tendency to peripheral vazokonstriktorny reactions; in late stages it can be noted . Peripheral hypostases come to light at an aortal stenosis of heavy degree. At percussion expansion of borders of heart is defined to the left and down; palpatorno the shift of a top push, systolic trembling in a jugular pole is felt.
Rough systolic noise over an aorta and over the mitralny valve, muting of I and II tones on an aorta is Auskultativny signs of an aortal stenosis. The specified changes are also registered at a phonocardiography. According to the ECG signs of a hypertrophy of the left ventricle, arrhythmia, sometimes – blockade are defined.
In the period of a decompensation on roentgenograms expansion of a shadow of the left ventricle in the form of lengthening of an arch of the left contour of heart, a characteristic aortal configuration of heart, poststenotichesky dilatation of an aorta, symptoms of pulmonary hypertensia comes to light. The thickening of gates of the aortal valve, restriction of amplitude of the movement of shutters of the valve in a systole, a hypertrophy of walls of the left ventricle is defined on an echocardiography.
For the purpose of measurement of a gradient of pressure between the left ventricle and an aorta sounding of cavities of heart which allows to judge degree of an aortal stenosis indirectly is carried out. Ventrikulografiya is necessary for detection of the accompanying mitralny insufficiency. Aortografiya and coronary angiography are applied to differential diagnostics of an aortal stenosis with aneurism of the ascending department of an aorta and IBS.
Treatment of an aortal stenosis
All patients, including with the asymptomatic, completely compensated aortal stenosis, have to be under careful observation of the cardiologist. Carrying out EhoKG each 6-12 months are recommended to them. Preventive reception of antibiotics before dental (treatment of caries, removal of teeth etc.) and other invasive procedures is necessary for this contingent of patients for the purpose of prevention of an infectious endocarditis. Conducting pregnancy with an aortal stenosis demands careful control of indicators of haemo dynamics from women. As the indication to termination of pregnancy serves heavy degree of an aortal stenosis or increase of symptoms of heart failure.
Medicamentous therapy at an aortal stenosis is directed to elimination of arrhythmias, prevention of IBS, normalization HELL, delay of progressing of heart failure.
Radical surgical correction of an aortal stenosis is shown at the first clinical manifestations of defect – emergence of short wind, anginozny pains, sinkopalny states. For this purpose the balloon valvuloplastika - endovascular balloon dilatation of an aortal stenosis can be applied. However often this procedure is ineffective and is followed by the subsequent recurrence of a stenosis. At not rough changes of shutters of the aortal valve (is more often at children with congenital defect) open surgical plasticity of the aortal valve (valvuloplastik) is used. In a children's heart surgery Ross's operation assuming change of the valve of a pulmonary artery in an aortal position is quite often carried out.
At the corresponding indications resort to carrying out plasticity of a nadklapanny or subvalvate aortal stenosis. Prosthetics of the aortal valve at which the struck valve completely is removed and replaced with a mechanical analog or a ksenogenny bioartificial limb remains by the main method of treatment of an aortal stenosis today. Patients with the artificial valve need lifelong reception of anticoagulants. In recent years perkutanny replacement of the aortal valve practices.
Forecast and prevention of an aortal stenosis
The aortal stenosis can proceed asymptomatically for many years. Emergence of clinical symptoms significantly increases risk of complications and a lethality.
The main, predictively as significant symptoms serve stenocardia, faints, left ventricular insufficiency – in this case average life expectancy does not exceed 2-5 years. At timely expeditious treatment of an aortal stenosis 5-year survival makes about 85%, 10-year-old — about 70%.
Measures of prevention of an aortal stenosis come down to the prevention of rheumatism, atherosclerosis, infectious endocarditis, etc. the promoting factors. Patients with an aortal stenosis are subject to medical examination and observation of the cardiologist and rheumatologist.