Mitral valve insufficiency
mitral valve insufficiency - the development of regurgitation of arterial blood in the cavities of the left heart during systolic contraction of ventricular myocardium, occurring against the backdrop of the broken wing clamping structures of the mitral valve.
The proportion of isolated defects in the form of mitral valve insufficiency among all possible cardiac defects account for at least 2%.Significantly more often in the patient there is a combined defeat of the mitral valve in the form of a combination of stenosis and insufficiency.
Mitral valve insufficiency causes
failure of the mitral valve of the heart, as opposed to a stenosis of the same location, is polietiologichesky pathology, that is, the development of its traits are influenced by a number of factors, although each of them individually can initiate the development of this defect.
Organic mitral insufficiency which occurs as a result of the primary lesion valve apparatus can be observed in the following diseases of cardiac and extracardiac nature: rheumatic fever, infection of the endocardium, myxomatous degeneration flaps and pronounced calcification in the projection valve, ischemic damage to the myocardium in atherosclerotic disease, connectivePathology of hereditary nature( Marfan's disease), systemic autoimmune lesion joints(Tissue scleroderma, dermatomyositis), traumatic heart damage.
The fundamental difference between the organic insufficiency of the mitral valve and the functional changes in the mitral valve is its development against the background of severe myocardial damage accompanied by the development of marked dilatation of the left ventricular cavity. Dilatational changes of the left ventricle over time provoke the dilatation of the valve ring and the displacement of the papillary muscles laterally, against which the dysfunction of the mitral valve leaves occurs, with complete absence of their organic damage. Hypertrophic cardiomyopathy
constrictive type is also accompanied by the development of symptoms of mitral valve insufficiency, and development of its pathogenic mechanism is hyperdynamic left ventricular contraction, which occurs during retraction in front of the flaps outflow tract enlarged left ventricle.
Mitral valve insufficiency
signs Mitral valve insufficiency is characterized by a slow flow with a gradual increase in clinical symptoms. In cardiological practice, a separate category of patients is distinguished, in whom there may be no clinical manifestations, and changes in the valvular apparatus are revealed during instrumental research techniques.
original complaint, which often impose patients with mitral valve insufficiency, are increasing shortness of breath, which is the result of venous stasis in the pulmonary parenchyma, decreased performance and fatigue caused by a decrease in cardiac output. Depending on the degree of damage to the valves of the valvular apparatus, respiratory disorders of cardiac origin may be minor or severe, up to the development of signs of pulmonary edema.
Mitral valve insufficiency has a range of specific changes diagnosed by an experienced cardiologist already in the period of primary objective research. Skin covers of patients with mitral valve insufficiency acquire a bluish tint in the projection of the distal parts of the limbs and face. With palpation of the pulse, as a rule, it is not possible to detect any changes, but in some cases, there are signs of a positive venous pulse. The marked widening of the borders of cardiac dullness, as well as the displacement and strengthening of the apical impulse, are observed only with a severe form of dilatation of the cavity of the left ventricle. When examining a patient with signs of pulmonary hypertension, a pathological pulsation in the projection of the fourth intercostal space along the left contour of the sternum is determined.
The most characteristic sign of mitral valve insufficiency is the presence of a pansystolic noise in the projection of the apex of the heart with an axillary region to the left. A specific symptom, characteristic exclusively for mitral valve insufficiency, is the amplification of noise in the translation of the trunk into a horizontal position on the left side. The degree of manifestation of noise depends more on the contractility of the left ventricular myocardium, rather than on the severity of regurgitation. If the noise is not strong, we can distinguish between the weakening of the first tone due to a violation of the complete closing of the mitral valve flaps. With severe regurgitation, there is a prognostically unfavorable sign - appearance of the third tone. Listening to the second tone accent in the projection of the pulmonary artery testifies to the development of signs of pulmonary hypertension.
Mitral valve insufficiency grade
The separation of mitral valve insufficiency is used to determine the degree of disturbance of central cardiohemodynamics, as well as determine the appropriateness of using surgical intervention.
The first( 1) degree of mitral valve insufficiency is characterized as a compensatory stage, that is, regurgitation of the blood flow is so minimal that it is not accompanied by cardiohemodynamic disorders. The only clinical symptom available to the patient in the compensatory stage of the disease may be the appearance of systolic murmur in the projection of the apex of the heart. In this situation, the patient is shown an echocardiographic study to determine the presence of regurgitation. Mitral insufficiency at this stage does not require the use of surgical methods of treatment.
second( 2) the degree of mitral regurgitation or subcompensation stage, accompanied by an increase of the reverse current volume of blood in the ventricle during systolic contraction, there are signs of compensatory hypertrophy of the left ventricular wall to compensate for hemodynamic disturbances. In this stage of the disease, the majority of patients note the increase in dyspnea with excessive physical activity, and auscultatory listening to a moderately pronounced systolic murmur in the projection of the apex of the heart. X-ray can determine the expansion of the boundaries of the left heart, as well as excessive pulsation. This stage has reflections on the ECG registration in the form of a left-handed curve and the appearance of signs of an overload of the left heart. Echocardiographic evidence is the presence of moderate regurgitation in the projection of mitral valve flaps. The stage of subcompensation is not a rationale for the application of surgical correction techniques.
The third( 3) degree of mitral valve insufficiency is characterized by the appearance of severe left ventricular decompensation caused by significant regurgitation of blood into the cavity of the left ventricle. Clinical symptoms indicative of the development of decompensated heart failure are progressive dyspnoea with minimal physical activity, and visualization of the pulsation of the anterior thoracic wall in the projection of the apex of the heart. Listening to severe systolic murmur in the projection of the apex of the heart is not difficult, and instrumental additional methods of examining the patient can determine the presence of left ventricular myocardial hypertrophy and marked reverse flow of blood through the bare valves of the mitral valve. The only effective method of treating mitral insufficiency at this stage is surgical.
The fourth( 4) degree of mitral valve insufficiency is accompanied by the addition of signs of right ventricular failure and is called "dystrophic".Distinctive visual symptoms are pronounced pulsation of the cervical veins and displacement of the apical impulse, as well as its amplification. The insufficiency of the mitral valve in this category of patients is accompanied not only by hemodynamic disorders, but also by the failure of the rhythm of the cardiac activity. Radiography allows you to visualize the pronounced widening of the shadow of the mediastinum by increasing all parts of the heart, as well as the appearance of signs of stagnation in the system of the small circle of the circulation. In this stage of the disease, extracardiac symptoms of functional changes in the kidneys and liver appear. Surgical correction methods are widely used and in most cases have a favorable outcome.
The fifth( 5) degree of mitral valve insufficiency is terminal and characterized by the manifestation in the patient of the entire clinical symptom complex, characteristic of the third stage of cardiovascular failure. The severity of the patient's condition does not allow for surgical intervention, and the prognosis of mitral valve insufficiency is extremely unfavorable at this stage. In the terminal stage of the disease, complications are often observed, each of which can cause a lethal outcome of the disease: paroxysmal form of atrial fibrillation, infective endocarditis, and systemic thromboembolism of vessels of different calibres.
Mitral valve deficiency treatment
The degree of severity of regurgitation in the projection of the mitral valve is influenced by the magnitude of systolic pressure in the aortic lumen, so it is pathogenetically justified to appoint vasodilators for a long time. The drugs of choice in this situation are ACE inhibitors in a dosage that allows to keep the systolic pressure at the level of 120 mm Hg.(Berlipril in the initial daily dosage of 2.5 mg, followed by titration of the drug to the therapeutic dose and continuous intake of the drug).The most recent randomized trials prove the need for vasodilators even in asymptomatic mitral valve failure with minimal regurgitation.
Already with the second-third degree of mitral valve insufficiency, when there are dilatation changes in the cavities of the left heart, it is advisable to use anticoagulants for life as a prevention of thromboembolic complications( Aspecard in a daily dose of 100 mg orally).
In a situation where the patient has electrocardiographic signs of arrhythmia, the use of adrenoblockers( Metoprolol in an average daily dose of 100 mg orally) is recommended.
The use of surgical methods for correcting mitral valve insufficiency is demonstrated in the following situations:
- regurgitation level is about 40% of cardiac output;
- the absence of a positive result from the use of massive antibiotic therapy in the aggressive course of endocarditis of infectious nature, complicating the course of the underlying disease;
- marked sclerotic changes in the valve apparatus, which are irreversible;
- marked dilatation enlargement of the left ventricle with signs of systolic dysfunction;
are the only or multiple episodes of vascular thromboembolism.
Currently, the cardiosurgical branch of medicine allows the use of the newest reconstructive surgical manuals, which allow to preserve the structure of the valve apparatus as much as possible. In a situation where there are pronounced sclerotic changes in valve flaps and it is not possible to perform surgical decalcification, a prosthesis technique using both synthetic and xenopericardial materials is used. In order to eliminate the rigidity of the valve structures, the valvuloplasty technique is used, which in most cases completely eliminates signs of regurgitation.
