Differential diagnosis of hypertrophic cardiomyopathy and myocardial hypertrophy of secondary origin. Obstructive cardiomyopathy Slight hypertrophy of the intravaginal

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Other hypertrophic cardiomyopathy (I42.2)

general information

Short description

Non-obstructive hypertrophic cardiomyopathy

Isolated myocardial hypertrophy of unknown nature was first described in the second half of the 19th century by French pathologists N. Lionville (1869) and L. Hallopeau (1869). They noted the narrowing of the outflow tract of the left ventricle due to thickening of the interventricular septum and gave this disease the name "left-sided muscular conus stenosus".

Hypertrophic cardiomyopathy- myocardial disease of unknown etiology, inherited in an autosomal dominant way, characterized by myocardial hypertrophy of the left and (or) occasionally right ventricle, more often, but not necessarily, asymmetric, as well as severe disorders of diastolic filling of the left ventricle in the absence of dilatation of its cavity and causes of hypertrophy hearts.

Classification

Classification of cardiomyopathies

By localization

1. LV hypertrophy

a) Asymmetric:

Hypertrophy of the basal segments of the IVS

Total IVS hypertrophy

Total hypertrophy of the IVS and LV free wall

Hypertrophy of the apex of the heart with possible extension to the free LV wall and septum

b) Symmetrical (concentric)

2. Hypertrophy of the pancreas

I I. According to the hemodynamic form

1. Non-obstructive

2. Obstructive

III. By pressure gradient(with obstructive form)

Stage 1 - pressure gradient less than 25 mm Hg

Stage 2 - less than 36 mm Hg

Stage 3 - less than 44 mm Hg

Stage 4 - from 45 mm Hg

IV . According to clinical manifestations

Asymptomatic course

Syncope

Rhythm disturbances

v. According to the stages of the clinical course

1. Compensation

2. Subcompensation

Etiology and pathogenesis

GKMP - hereditary disease which is passed on as an autosomal dominant trait. A genetic defect occurs when there is a mutation in one of 10 genes, each of which encodes components of the cardiac sarcomere protein and determines the development of myocardial hypertrophy. Currently, about 200 mutations responsible for the development of the disease have been identified.

There are several pathogenetic mechanisms for the development of the disease:

- Hypertrophy of the interventricular septum. As a result of the resulting genetic defect in the myocardial sarcomere, disproportionate hypertrophy of the interventricular septum can develop, which in some cases occurs even during the period of embryonic morphogenesis. At the histological level, changes in the myocardium are characterized by the development of metabolic disorders in the cardiomyocyte and a significant increase in the number of nucleoli in the cell, which leads to the disintegration of muscle fibers and the development of connective tissue in the myocardium (the phenomenon of "disarray" - the phenomenon of "disorder"). Disorganization of cardiac muscle cells and myocardial replacement connective tissue lead to a decrease in the pumping function of the heart and serve as the primary arrhythmogenic substrate, predisposing to the occurrence of life-threatening tachyarrhythmias.
- Obstruction of the output department of the left ventricle. Of great importance in HCM is obstruction of the LV, which occurs as a result of disproportionate hypertrophy of the interventricular septum, which contributes to the contact of the anterior leaflet mitral valve with an interventricular septum and a sharp increase in the pressure gradient in the VOLZH during systole.
- Violation of relaxation of the myocardium of the left ventricle. The prolonged existence of obstruction and hypertrophy of the interventricular septum leads to a deterioration in active muscle relaxation, as well as to an increase in the rigidity of the LV walls, which leads to the development of LV diastolic dysfunction, and in the terminal phase of the disease - systolic dysfunction.
- Myocardial ischemia. An important link in the pathogenesis of HCM is myocardial ischemia associated with the development of LV hypertrophy and diastolic dysfunction, which leads to hypoperfusion and increased myocardial fibrillation. As a result, thinning of the walls of the left ventricle, its remodeling and development of systolic dysfunction occur.

Epidemiology

Hypertrophic cardiomyopathy occurs with a frequency of 1:1000-1:500. It is generally accepted that it is most common among residents of Asia and the Pacific coast, especially in Japan. Men get sick more often than women. It is more common in young people, being a common cause of sudden cardiac death in them. About half of all cases of the disease are familial forms. The annual mortality from HCM is 1-6%.

Factors and risk groups

Risk factors for sudden death in hypertrophic cardiomyopathy:

Manifestation of the disease at a young age (up to 16 years),
- a family history of episodes of sudden death,
- Frequent syncope
- short episodes of ventricular tachycardia detected during 24-hour ECG monitoring,
- pathological change level blood pressure during loads.

Clinical picture

Symptoms, course

HCM can manifest at any age. The clinical picture is usually variable and patients may remain stable for a long period of time.

The classic triad of symptoms in hypertrophic cardiomyopathy includes exertional angina, dyspnea on exertion, and syncope. Pain in chest are noted in 75% of patients with hypertrophic cardiomyopathy, classical angina pectoris - in 25%.

Dyspnea and often accompanying chest pain, dizziness, syncope and pre-syncope usually occur with preserved LV systolic function. These symptoms are associated with the occurrence of diastolic myocardial dysfunction and other pathophysiological mechanisms (myocardial ischemia, LV obstruction and concomitant mitral regurgitation, AF).

Chest pain in the absence of atherosclerotic lesions of the coronary vessels, it can be both typical for angina pectoris and atypical.

Syncope and dizziness are characteristic, first of all, for patients with an obstructive form of HCM due to hemodynamic obstruction (decrease in the lumen of the LV). In most cases, they occur suddenly against the background of full health during a period of physical or emotional stress, however, they can also occur at rest. Most often, syncope is observed in young patients; in many of them, episodes of ventricular tachycardia and conduction disturbances are recorded during daily ECG monitoring.

A significant number of patients (5-28%) develop atrial fibrillation, which increases the risk of thromboembolic complications.

In an objective study of patients with a non-obstructive form of hypertrophic cardiomyopathy, there may be no deviations from the norm, but sometimes an increase in the duration of the apex beat, IV heart sound are determined.

Diagnostics

ECG in 12 leads.

Various ECG changes are recorded in 92-97% of patients, they serve as the earliest manifestation of HCM and may precede the development of myocardial hypertrophy, detected by echocardiography. Strictly specific ECG signs of HCM, as well as clinical ones, do not exist.
The most common are ST-segment changes, T wave inversion, signs of more or less pronounced left ventricular hypertrophy, deep Q waves, and signs of left atrial hypertrophy and overload. Less often, blockade of the anterior superior branch of the left leg of the His bundle and signs of hypertrophy of the right atrium, in isolated cases, of the right ventricle, are noted. Complete blockade legs of the bundle of His is not typical. Common ECG changes with HCM are negative T waves, in some cases in combination with ST segment depression, which are recorded in 61-81% of patients. Giant, over 10 mm deep, negative T waves in chest leads are very characteristic of the apical form of this disease, in which they are of great diagnostic value. End part changes ventricular complex in HCM are due to myocardial ischemia or small-focal cardiosclerosis. The detection of deep Q waves and negative T waves, especially with complaints of anginal pain, is a common cause of erroneous diagnosis of coronary artery disease and necessitates the differential diagnosis of HCM with this disease.

Holter ECG monitoring. Holter ECG monitoring for the diagnosis of rhythm and conduction disorders is indicated for patients with a high risk of sudden death, primarily with syncope, the presence of cases of sudden death in the family, as well as with clinical and ECG signs myocardial ischemia. It is also advisable to use it to monitor the effectiveness of antiarrhythmic therapy.

Phonocardiography. Very characteristic, but non-specific, is a pathological increase in the III and especially IV heart sounds. An important sign of subaortic obstruction is the so-called late, not associated with the I tone, systolic murmur of a diamond-shaped or ribbon-shaped shape with an epicenter at the apex or in the III-IV intercostal space at the left edge sternum. It is carried out in the axillary region and less often on the base of the heart and vessels of the neck. Distinctive features noise, allowing to suspect obstructive HCM, are specific changes in its amplitude and duration during physiological and pharmacological tests aimed at increasing or decreasing the degree of obstruction and associated mitral insufficiency. This nature of the noise dynamics is not only of diagnostic value, but is also a valuable criterion for the differential diagnosis of HCM with primary lesions of the mitral and aortic valves. Noise may be preceded by an additional tone, which is formed when the mitral valve comes into contact with the interventricular septum. In some patients in diastole, a short, low-amplitude inflow murmur is recorded following the III tone, that is, relative mitral or occasionally tricuspid stenosis. In the latter case, the noise increases on inspiration. With a significant severity of obstruction to blood flow, a paradoxical splitting of the II tone is determined due to the lengthening of the period of left ventricular ejection in proportion to the magnitude of the systolic pressure gradient.

X-ray examination of the chest. The data of X-ray examination of the heart are not very informative. Even with significant myocardial hypertrophy, significant changes in the shadow of the heart may be absent, since the volume of the cavity of the left ventricle is not changed or reduced. In some patients, there is a slight increase in the arches of the left ventricle and left atrium and rounding of the apex of the heart, as well as signs of moderate venous pulmonary hypertension. The aorta is usually reduced.

Main ECHOCG signs :
- Asymmetric left ventricular myocardial hypertrophy but. The generally accepted criterion for HCM is an interventricular septal thickness of more than 15 mm with normal or increased LV posterior wall thickness. Given that the disease is genetically determined, the degree of hypertrophy may be different. However, the presence of symmetrical hypertrophy does not exclude the diagnosis of HCM.

- Obstruction of the outflow tract of the left ventricle. The hemodynamic systolic pressure gradient in the VOLZH is determined using Doppler scanning. A gradient of more than 30 mm Hg is considered diagnostically significant. (flow velocity in VOLZH - 2.7 m/s). Perform a test with physical activity to determine the degree of gradient in the VOLZH. The dobutamine test is not used due to the high risk of developing life-threatening arrhythmias.
- Anterior systolic movement of the anterior leaflet of the mitral valve. Dilatation of the left atrium, mitral regurgitation, and, in the terminal stage, LV dilatation are also often detected.

Stress echocardiography used to detect coronary heart disease associated with HCM, which has important prognostic and therapeutic value.

Radionuclide ventriculography as the most reproducible method for assessing the systolic and diastolic function of not only the left, but also the right ventricle, it is mainly used to monitor patients with HCM in dynamics and to evaluate the effectiveness of therapeutic measures.

Magnetic resonance imaging with It is the most accurate method for assessing the morphology of the heart, which plays a key role in the diagnosis of HCM. Thus, magnetic resonance imaging allows obtaining additional information compared to EchoCG on the distribution of hypertrophy in 20-31% of patients with HCM (F. Sardinelli et al., 1993; J. Posma et al., 1996) and provides measurements of the thickness of 97% of the segments of the left ventricle compared with 67% when using echocardiography (G. Pons-Llado et al., 1997). Thus, magnetic resonance imaging can serve as a kind of "gold standard" for assessing the prevalence and severity of myocardial hypertrophy in patients with HCM.

Positron emission tomography presents a unique opportunity for non-invasive assessment of regional perfusion and myocardial metabolism. Preliminary results of its use in HCM showed a decrease in the coronary expansion reserve not only in hypertrophied, but also unchanged in thickness segments of the left ventricle, which is especially pronounced in patients with anginal pain. Impaired perfusion is often accompanied by subendocardial ischemia.

When measuring pressure in the cavities of the heart The most important diagnostic and therapeutic value is the detection of the systolic pressure gradient between the body and the outflow tract of the left ventricle at rest or during provocative tests. This symptom is characteristic of obstructive HCM and is not observed in non-obstructive form of the disease, which does not allow excluding HCM in its absence. When registering the pressure gradient in the cavity of the left ventricle with respect to its outflow tract, it is necessary to make sure that it is due to subaortic obstruction to the expulsion of blood, and is not the result of a tight grip of the end of the catheter by the walls of the ventricle during the so-called "elimination" or "obliteration" of its cavity. Along with the subaortic gradient, an important sign of an obstruction to the expulsion of blood from the left ventricle is a change in the shape of the pressure curve in the aorta. As in the sphygmogram, it takes the form of a "peak and dome". In a significant proportion of patients with HCM, regardless of the presence or absence of a subaortic gradient, an increase in end-diastolic pressure in the left ventricle and pressure in the pathways of its inflow - in the left atrium, pulmonary veins , "pulmonary capillaries" and pulmonary artery. Wherein pulmonary hypertension is passive, venous. An increase in end-diastolic pressure in a hypertrophied left ventricle is due to a violation of its diastolic compliance, which is characteristic of HCM. Sometimes, in the terminal stage of the development of the disease, it is aggravated as a result of the addition of systolic dysfunction of the myocardium.

coronary angiography. It is performed with HCM and persistent retrosternal pain (frequent attacks of angina pectoris):

In persons over 40 years of age;
in persons with risk factors for coronary artery disease;
in persons with established diagnosis CAD before invasive intervention (eg, septal myectomy or alcohol septal ablation).

Endomyocardinal biopsy of the left or right ventricle is recommended in cases where, after a clinical and instrumental examination, there are doubts about the diagnosis. When characteristic pathohistological signs of the disease are identified, a conclusion is made about the correspondence of morphological changes in the myocardium to the clinical diagnosis of HCM. On the other hand, the detection of structural changes specific to any other myocardial lesion (for example, amyloidosis) makes it possible to exclude HCM.

In the presence of Doppler echocardiography and magnetic resonance imaging, EMB is practically not used for diagnosing HCM.

Laboratory diagnostics

In order to exclude other most common cardiac diseases, it is necessary to conduct a biochemical blood test (lipid spectrum, biomarkers of myocardial necrosis, blood electrolyte composition, blood serum glucose), an assessment of the functional state of the kidneys, liver, and general clinical blood and urine tests.

Differential Diagnosis

Differential diagnosis is carried out with a number of diseases accompanied by the development of left ventricular hypertrophy, primarily "athlete's heart", acquired and congenital malformations, DCMP, and with a tendency to increase blood pressure - essential arterial hypertension. Differential diagnosis with heart defects accompanied by systolic murmur is of particular importance in cases of obstructive HCM. In patients with focal and ischemic changes on the ECG and anginal pain, the primary task is the differential diagnosis with coronary artery disease. With a predominance in clinical picture signs of congestive heart failure in combination with a relatively small increase in the size of the heart HCM should be differentiated from atrial myxoma, chronic cor pulmonale and diseases occurring with restriction syndrome - constrictive pericarditis, amyloidosis, hemochromatosis and sarcoidosis of the heart and restrictive cardiomyopathy.

"Athlete's Heart. Differential diagnosis of non-obstructive HCM, especially with relatively mild left ventricular hypertrophy (wall thickness 13-15 mm), from the "athlete's heart" is a difficult task, quite common in sports medicine. The importance of its decision is due to the fact that HCM is the main cause of death of young professional athletes, and therefore the formulation of such a diagnosis serves as the basis for their disqualification. The probable HCM in these controversial cases is indicated by the presence on the ECG, in addition to signs of left ventricular hypertrophy, of other changes. With Doppler echocardiography, an unusual distribution of myocardial hypertrophy, a decrease in the end-diastolic diameter of the left ventricle less than 45 mm, an increase in the size of the left atrium, and other signs of impaired diastolic filling of the left ventricle testify in favor of HCM.

Coronary artery disease. Most often, HCM has to be differentiated from chronic and less often sharp forms ischemic heart disease. In both cases, anginal pain in the region of the heart, shortness of breath, disturbances heart rate, concomitant arterial hypertension, additional tones in diastole, small and large focal changes and signs of ischemia on the ECG. EchoCG is important for making a diagnosis, in which some patients have segmental contractility characteristic of IHD, moderate dilatation of the left ventricle and a decrease in its ejection fraction . Left ventricular hypertrophy is very moderate and often symmetrical. The impression of a disproportionate thickening of the interventricular septum can be created by the presence of zones of akinesia due to postinfarction cardiosclerosis in the region of the posterior wall of the left ventricle with compensatory hypertrophy of the septal myocardium. At the same time, in contrast to asymmetric ventricular septal hypertrophy as a form of HCM, septal hypertrophy is accompanied by hyperkinesia. In cases of marked dilatation of the left atrium due to concomitant mitral regurgitation in coronary artery disease, dilatation of the left ventricle is invariably noted, which is unusual for patients with HCM. The diagnosis of HCM can be confirmed by the detection of signs of a subaortic pressure gradient. In the absence of echocardiographic data in favor of subaortic obstruction, differential diagnosis is much more difficult. The only reliable method for recognizing or excluding CAD in such cases is radiopaque coronary angiography. In middle-aged and older people, especially in men, it is necessary to keep in mind the possibility of combining HCM with coronary artery disease.

Essential arterial hypertension. For differential diagnosis, the most difficult is HCM that occurs with an increase in blood pressure, which should be distinguished from isolated essential arterial hypertension, accompanied by hypertrophy of the left ventricle with a disproportionate thickening of the interventricular septum. In favor of essential arterial hypertension is evidenced by a significant and persistent increase in blood pressure, the presence of retinopathy, as well as an increase in the thickness of the intima and media. carotid arteries, not typical for patients with HCM. Particular attention should be paid to identifying signs of subaortic obstruction. In the absence of a subaortic pressure gradient, probable HCM, in contrast to essential arterial hypertension, is indicated by a significant severity of asymmetric hypertrophy of the interventricular septum with an increase in its thickness by more than 2 times compared to the posterior wall of the left ventricle, as well as the detection of HCM in at least one of 5 adult blood relatives. On the contrary, in the absence of signs of HCM in 5 or more members of the patient's family, the probability of this disease does not exceed 3%.

Complications

The course of the disease can be complicated by the development of such complications as:

Sudden cardiac death (SCD)
- thromboembolism
- progression of chronic heart failure (CHF).

Treatment

TO general activities include limiting significant physical activity and the prohibition of sports activities that can cause exacerbation of myocardial hypertrophy, an increase in the intraventricular pressure gradient and the risk of VS. To prevent infective endocarditis in situations associated with the development of bacteremia, with obstructive forms of HCM, antibiotic prophylaxis is recommended, similar to that in patients with heart defects.

The basis of drug therapy for HCM is drugs with a negative inotropic effect: β-blockers and calcium channel blockers (verapamil).

β-blockers became the first and remain to this day the most effective group medicines used in the treatment of HCM. they should be prescribed to patients regardless of the severity of the intraventricular pressure gradient at rest. It is preferable to refrain from prescribing β-aope-noreceptor blockers with intrinsic sympathomimetic activity (pindolol, oxprenolol). Propranolol is prescribed at a dose of 240-320 mg per day or more (the maximum daily dose is 480 mg), metoprolol is prescribed at a dose of 200 mg per day or more. Cardioselective blockers of beta-adrenergic receptors in hypertrophic cardiomyopathy do not have advantages over non-selective ones, since at high doses, selectivity is practically lost.

In case of contraindications to the appointment of beta-blockers or incomplete resolution of symptoms, an alternative may be calcium channel blockers. Among the calcium channel blockers, the drug of choice is verapamil (Isoptin, Finoptin). It provides a symptomatic effect in 65-80% of patients. When prescribing calcium channel blockers, maximum caution is required in the presence of severe hypertrophy and very high pressure filling of the left ventricle. It should be borne in mind that calcium channel blockers, including verapamil, with long-term use can increase diastolic pressure and reduce cardiac output. Treatment with verapamil should begin with the appointment of low doses - 20-40 mg 3 times a day, gradually increasing to a daily dose of 240-320 mg or more. Clinical improvement when taking verapamil is accompanied by an increase in exercise tolerance.

For the treatment of arrhythmias, antiarrhythmic drugs are used, of which the most effective are disopyramide and amiodarone. Disopyramide (ritmilen), which belongs to class IA antiarrhythmics, has a pronounced negative inotropic effect; in patients with HCM, it can reduce the level of left ventricular outflow tract obstruction and positively affects the structure of diastole. The initial dose is usually 400 mg / day with a gradual increase to 800 mg. In this case, it is necessary to control the duration of the Q-T interval according to the ECG.
Amiodarone is the only drug against which the elimination of ventricular tachyarrhythmias, a decrease in the incidence of sudden death and an improvement in the prognosis of the disease has been noted to date. Amiodarone is prescribed at a daily dose of 1200 mg for 5-7 days, then at a daily dose of 800 mg and 600 mg during the 2nd and 3rd weeks of treatment, followed by a transition to maintenance daily dose 200 mg.

When treating HCM with symptoms of heart failure, the following points should be considered:
diuretics are contraindicated which, although effective in reducing pulmonary congestion, can cause hypovolemia, which can increase outflow tract obstruction in patients! Too long use of diuretics can cause a decrease in stroke volume and cardiac output.
Vasodilators (nitroglycerin, sodium nitroprusside) have limited use due to the possible risk of severe hypotension and a decrease in the size of the left ventricular cavity, which can worsen the patient's condition.
Inotropic agents aimed at stimulating systolic output (cardiac glycosides and pressor amines), may have an unfavorable hemodynamic effect - they increase the obstruction of the outflow tract and do not reduce elevated end-diastolic pressure, they can cause the development of asystole. However, digoxin may be used in patients with diastolic dysfunction and atrial fibrillation to decrease heart rate and/or restore sinus rhythm.
Drugs of choice for the treatment of CHF may be ACE inhibitors due to their ability to block the renin-angiotensin system and cause regression of left ventricular hypertrophy.

In the absence of a clinical effect from active drug therapy in symptomatic patients of III-IV functional class according to the classification of the New York Heart Association with severe asymmetric IVS hypertrophy and a subaortic pressure gradient at rest equal to 50 mm Hg. Art. or more, surgical treatment is indicated (reference to treatment from I42.1)

Forecast

Non-obstructive forms of HCM have, in general, a more favorable course with less severity of functional limitation and longer periods of stabilization. The prognosis is most favorable with a long asymptomatic course of the disease and an uncomplicated family history, especially with the apical form of HCM. In some such cases, the disease may not affect life expectancy.

Most patients with HCM die suddenly, regardless of how long ago the disease was. The poor prognosis in children, most of whom are asymptomatic, is associated with a positive family history of sudden death. In adolescents and persons of young and middle age (from 15 to 56 years), the main factor that aggravates the prognosis is susceptibility to fainting. In older patients, shortness of breath and pain in the heart area during physical exertion are prognostically unfavorable.

There are 5 main variants of the course of the disease and outcomes:
- stable, benign course;
- sudden death;
- progressive course - increased shortness of breath, weakness, fatigue, pain syndrome (atypical pain, angina pectoris), the appearance of syncope, disorders of LV systolic dysfunction;
- "final stage" - further progression of the phenomena of congestive heart failure associated with remodeling and LV systolic dysfunction;
- the development of atrial fibrillation and related complications, in particular thromboembolic.

Hospitalization

Indications for hospitalization

Clinically significant worsening of CHF symptoms.
- Cardiac arrhythmias: new-onset, hemodynamically unstable, life-threatening.
- Circulatory arrest (asystole or ventricular fibrillation).
- Brain symptoms (syncope, presyncope).
- Persistent anginal pain.

Prevention

Prevention of the disease is to identify it at an early stage, which allows you to start early treatment of the disease and prevent the development of severe myocardial hypertrophy. EchoCG must be performed without fail in the "blood" (genetic) relatives of the patient. All other persons are shown a detailed examination in the presence of manifestations similar to the disease: fainting, angina pectoris, etc. Screening (all in a row) ECG and EchoCG during the annual medical examination are also useful.

Information

Information

1. Treatment of heart failure. Recommendations working group for the study of heart failure European Society Cardiologists. Rus. honey. magazine Appendix. 1999.
2. Amosova E.N. Cardiomyopathy. Kyiv: "Book Plus", 1999; 421 p.
3. Kushakovsky M.S. Chronic congestive heart failure. Idiopathic myocardiopathies. St. Petersburg: "Foliant", 1998; 320 p.
4. Moiseev V.S., Sumarokov A.V., Styazhkin V.Yu. Cardiomyopathy. M.: Medicine 1993; 176 p.
5. Guide to outpatient cardiology, edited by Yu. N. Belenkov, R. G. Oganov, GEOTAR-Media publishing house, - 2007.-400 p.
6. Polyakov V.P., Nikolaevsky V.N., Pichko G.A. Non-coronary and infectious diseases of the heart (modern aspects of the clinic, diagnosis, treatment): Monograph.-Samara, 2010,-355p.
7. Internal illnesses by Tinsley R. Harrison / Ed. E. Fauci, J. Braunwald, K. Isselbacher, J. Wilson, J. Martin, D. Kasper, S. Hauser and D. Longo: In 7 vols. - M.: Practice -Mc-Grow_Hill, 2005.
8. Clinical guidelines. Cardiology / Ed. Yu.N. Belenkova, R.G. Oganov. - M.: GEOTAR-Media, 2007.
9. B. Griffin, E. Topol "Cardiology" Moscow, 2008
10. Kovalenko VN, Nesukai EG Non-coronary heart disease: a practical guide / Ed. V. N. Kovalenko. K .: "Morion", 2001. - 480 p.

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Name:

Classification

Clinical picture

Diagnostics

Treatment:

Drug therapy

Content

Thickening of the myocardial wall (the muscular membrane of the heart) is a pathological condition. In medical practice, there are different kinds cardiomyopathy. Morphological changes in the main organ of the circulatory system lead to a decrease in the contractility of the heart, and there is a lack of blood supply.

What is hypertrophic cardiomyopathy

A disease characterized by thickening (hypertrophy) of the wall of the left (rarely right) ventricle of the heart is called hypertrophic cardiomyopathy (HCM). Myocardial muscle fibers are arranged randomly - this is a characteristic feature of the disease. In most cases, asymmetric thickening is observed, hypertrophy of the interventricular septum develops.

Pathology is characterized by a decrease in the volume of the ventricle, a violation of the pumping function. The heart has to contract frequently to deliver enough blood to the organs. The consequence of these changes is a violation of the heart rhythm, the appearance of heart failure. 30–50 years is the average age of patients diagnosed with hypertrophic cardiomyopathy. The disease is more common in men. Pathological condition is fixed in 0.2–1.1% of the population.

Causes

HCM is a hereditary disease. Occurs as a result of gene mutation. The type of transmission of altered hereditary structures is autosomal dominant. Pathology is not only congenital. In some cases, mutations occur under the influence of unfavorable environmental factors. The consequences of changing the genetic code are as follows:

• the biological synthesis of myocardial contractile proteins is disrupted;
• muscle fibers have an incorrect location, structure;
• muscle tissue is partially replaced by connective tissue, myocardial fibrosis develops;
• altered cardiomyocytes (cells of the muscle membrane) do not work in a coordinated manner, with an increased load;
• muscle fibers thicken, myocardial hypertrophy occurs.

One of two pathological processes leads to thickening of the muscular membrane (compensatory hypertrophy):

1. Violation of the diastolic function of the myocardium. During the period of relaxation of the heart (diastole), the ventricle is not filled with blood enough due to poor myocardial extensibility. This leads to an increase in diastolic pressure.
2. Obstruction (impaired patency) of the output tract of the left ventricle. There is hypertrophy of the myocardium of the interventricular septum. The blood flow is impeded due to the violation of the mobility of the mitral valve leaflet. At the moment of ejection of blood between the cavity of the left ventricle and the initial section of the aorta, there is a difference in systolic pressure. For this reason, part of the blood is retained in the heart. As a result, the end-diastolic pressure of the left ventricle rises. Myocardial hypertrophy, dilatation (expansion) of the left atrium are consequences of compensatory hyperfunction.

Classification

The criteria underlying the classification of the disease are different. There are the following types of illness:

Taking into account the prevailing complaints of patients, nine forms of pathology are distinguished. In the presence of common symptoms each variant of HCM has specific features. Clinical forms are as follows:

• lightning fast;
• pseudovalvular;
• arrhythmic;
• cardialgic;
• oligosymptomatic;
• vegetodistonic;
• infarct-like;
• decompensation;
• mixed.

Clinical and physiological classification distinguishes four stages of the development of the disease. The main criterion is the difference in systolic pressure in the outflow tract of the left ventricle (LVOT) and in the aorta:

• The first stage is an indicator of pressure in the LVOT, not more than 25 mm Hg. Art. The patient has no complaints of worsening condition.
• The second stage is a pressure gradient of about 36 mm Hg. Art. The condition worsens with physical exertion.
• The third stage - the pressure difference is up to 44 mm Hg. Art. Shortness of breath is observed, angina pectoris develops.
• The fourth stage is the systolic pressure gradient in the LVOT more than 88 mm Hg. Art. There is a violation of blood circulation, sudden death is possible.

Symptoms of hypertrophic cardiomyopathy

The disease may not appear for a long time. Hypertrophic cardiomyopathy is the main cause of death in young athletes who were unaware of the presence of a hereditary disease. 30% of patients with GTCS have no complaints and do not experience deterioration general condition. Symptoms of pathology are as follows:

• fainting, dizziness, shortness of breath, cardialgia, angina pectoris and other conditions associated with low blood ejection syndrome;
• heart failure of the left ventricle;
• violations of the rhythm of heart contractions (extrasystoles, paroxysms, arrhythmias);
• sudden death (against the background of the complete absence of symptoms);
• the occurrence of complications - infective endocarditis, thromboembolism.

Diagnostics

The first signs of the disease appear in childhood, but in most cases it is diagnosed in adolescence or in patients 30-40 years old. On the basis of a physical examination (assessment of the external condition), the doctor makes a primary diagnosis. Examination helps to identify the expansion of the boundaries of the heart, listen to the characteristic systolic murmur, if there is an obstructive form of the disease, an accent of the second tone is possible on the pulmonary artery. When examining the jugular veins for hypertrophy, poor contractility of the right ventricle is indicated by a well-defined wave A.

Additional diagnostic methods include:

• Electrocardiography. In the presence of pathology, the ECG is never normal. The study allows you to establish an increase in cardiac chambers, impaired conduction and frequency of contractions.
• Chest x-ray. Helps to detect changes in the size of the atria and ventricles.
• Echocardiography. The main method for detecting the localization of thickening of the heart wall, the degree of obstruction of the blood flow, diastolic dysfunction.
• Monitoring of the electrocardiogram during the day, with the use of physical activity. The method is important for the prevention of sudden death, the prognosis of the disease, and the detection of cardiac arrhythmias.
• radiological methods. Ventriculography (examination of the heart with the introduction of a contrast agent), magnetic resonance imaging (MRI) is performed. They are used in difficult cases to identify and accurately assess pathological changes.
• Genetic diagnostics. The most important method for assessing the prognosis of the disease. Genotype analysis is carried out in the patient and his family members.

Treatment of hypertrophic cardiomyopathy

If the patient has symptoms of hypertrophic cardiomyopathy, a wide range of drugs are used. With the ineffectiveness of drug therapy in the case of an obstructive form of pathology, surgical and alternative interventional methods of correction are used. A special treatment regimen is prescribed for patients with a high risk of sudden death or the last stage of the disease. The goals of therapy are:

• reduction in the severity of symptoms and clinical manifestations of pathology;
• improving the "quality of life" of the patient, improving the functional ability;
• ensuring a positive prognosis of the disease;
• prevention of sudden death and disease progression.

Medical therapy

Patients with symptoms of HCM are advised to limit physical activity. This rule should be strictly followed by patients with an obstructive form of the disease. Loads provoke the development of arrhythmias, fainting, an increase in the pressure gradient of the LVOT. To alleviate the condition with moderately severe symptoms of HCM, drugs of different pharmacological groups are prescribed:

• Beta blockers (Propranolol, Metoprolol, Atenolol) or calcium channel blockers (Verapamil). They reduce the heart rate, lengthen the diastole (relaxation phase), improve the filling of the ventricles with blood, and reduce diastolic pressure.
• Calcium antagonists (Finoptin, Amiodarone, Cardil). Medicines reduce the amount of calcium in the coronary arteries, improve the relaxation of structures (diastole), and stimulate myocardial contractility.
• Anticoagulants (Fenindione, Heparin, Bivalirudin). Medicines reduce the risk of developing thromboembolism.
• Diuretics (Furosemide, Indapamed), ACE inhibitors (Captopril, Ramipril, Fosinopril). The drugs are recommended for patients with heart failure.
• Antiarrhythmic drugs (Disopyramide, Amiodarone).

With HCM, the intake of cardiac glycosides, nifedipine, nitrites is contraindicated. These drugs contribute to the development of obstruction.

Surgery

Cardiosurgical treatment is advisable in the absence of the effectiveness of the reception pharmacological preparations. Surgical intervention is indicated for patients who have a pressure difference between the left ventricle (LV) and the aorta of more than 50 mm Hg. Art. at rest and during exercise. In order to alleviate the patient's condition, the following surgical techniques are used:

• Transaortal septal myectomy (SME). It is recommended for patients who experience fainting, shortness of breath, chest pain during physical exertion. The essence of the operation is to remove part of the interventricular septum. This manipulation provides good LV contractility and free pushing of blood into the aorta.
• Percutaneous alcohol ablation. The operation is prescribed for patients with contraindications to SME, elderly patients who have inadequate blood pressure under load conditions. Sclerosing agents (for example, alcohol solutions) are introduced into the hypertrophied interventricular septum.
• Dual chamber pacing. The technique is used for patients with contraindications for surgical intervention. Manipulation improves the work of the heart, increases cardiac output.
• Implantation of an artificial mitral valve. Prosthetics is recommended for patients whose poor outflow of blood is not due to thickening of the interventricular septum, but as a result of eversion of the valve into the aortic lumen.
• Installing an ICD (implantable cardioverter defibrillator). Indications for such a procedure are a high risk of sudden death, cardiac arrest, persistent ventricular tachycardia. To install an ICD, an incision is made in the subclavian region, electrodes are inserted through a vein (there may be 1–3 of them, depending on the pacemaker model) and placed under X-ray control inside the heart.
• Heart transplant. It is prescribed for patients with the last stage of heart failure, in the absence of the effect of drug treatment.

Surgical operations significantly improve the condition of patients, increase the tolerance of physical activity. Surgery does not protect against further development pathological thickening of the myocardium and complications. In the postoperative period, the patient must regularly undergo examinations using hardware diagnostic techniques and take pharmacological preparations prescribed by the doctor for life.

Forecast

Hypertrophic cardiomyopathy has different variants of development. The non-obstructive form proceeds stably, without pronounced symptoms. The consequence of the prolonged development of the disease is heart failure. In 5-10% of cases, the thickening of the myocardial wall stops on its own, the same percentage of the probability of turning hypertrophic cardiomyopathy into dilated one (stretching of the heart cavities).

Mortality in the absence of treatment is observed in 3-8% of cases. In half of patients, sudden death occurs due to severe ventricular arrhythmias, complete heart block, acute myocardial infarction. In 15–25%, coronary atherosclerosis develops. Infective endocarditis, in which the mitral and aortic valves are affected, occurs as a complication of the pathology in 9% of patients.

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Thickening of the interventricular septum is one of the most characteristic features diseases such as hypertrophic cardiomyopathy. With this violation, hypertrophy, or thickening of the walls of the right or left ventricles of the heart, is observed; especially often the disease affects the interventricular septum. Thickening of the interventricular septum occurs in approximately 70% of people with hypertrophic cardiomyopathy. This makes it harder for the heart to pump blood, which can lead to various health problems over time.

Symptoms of thickening of the interventricular septum

In a large number of people, thickening of the interventricular septum and hypertrophic cardiomyopathy go undiagnosed for a long time, because the disease may not cause any symptoms for many years. A person with such a disorder can lead a completely normal life, but with intense physical exertion, the disease makes itself felt. This violation has repeatedly caused the death of young athletes, among them - Miklós Feher, striker of the Hungarian national football team. At 24, his heart stopped right during the match, and attempts to resuscitate the athlete were unsuccessful - a few hours later he died in the hospital. Only at autopsy was he diagnosed with hypertrophic cardiomyopathy.

Apparently, until some time, a heart with a thickened interventricular septum can cope even with serious stress, and a person will feel fine. In some cases, however, the violation may cause the following symptoms:

• Shortness of breath, especially during exercise;
• Chest pain, which occurs, as a rule, is also the time of training;
• Dizziness and dizziness;
• Increased fatigue;
• Palpitations of the heart - a very strong and frequent heartbeat that occurs from time to time;
• Heart murmurs, which the doctor may detect during the examination.

The symptoms listed above can be caused by many disorders, but in any case they should not be ignored. If any of these signs appear, see your doctor as soon as possible for an examination.

Contact immediately medical care if the following symptoms persist for more than five minutes:

• fast or irregular heartbeat;
• Labored breathing;
• Chest pain.

Causes and possible complications

Thickening of the interventricular septum is most often caused by gene mutations that cause part of the heart muscle to become abnormally thick. Unlike many other heart diseases, this disorder is not associated with bad habits or excess weight. There is a 50% chance that the children of a person with this disease will also suffer from hypertrophic cardiomyopathy. If this disorder was found in a person, his close relatives - parents, brothers and sisters, children - are also recommended to be examined by a cardiologist.

The consequences of thickening of the interventricular septum vary greatly from person to person. In some cases, a person may be unaware of their illness for years. This becomes known when people - especially young and active people - die from this disorder, but for obvious reasons, it is impossible to say how many people died in old age without knowing that they had hypertrophic cardiomyopathy. However, in some people, thickening of the interventricular septum can lead to the following consequences:

• Arrhythmia. A thickened interventricular septum, as well as anomalies in the structure of heart muscle cells, which are often observed in hypertrophic cardiomyopathy, can lead to disturbances in the conduction system of the heart, and this causes an irregular heartbeat, or arrhythmia. Atrial fibrillation, ventricular tachycardia and ventricular fibrillation are types of arrhythmias that can be caused by hypertrophic cardiomyopathy;
• Violation of the outflow of blood from the heart muscle. This may cause symptoms such as shortness of breath on exertion, chest pain , dizziness and, sometimes, fainting;
• dilated cardiomyopathy. Over time, the hardened walls of the heart muscle can become weak and work less efficiently. Dilated cardiomyopathy is a disorder in which the cavities of the heart are stretched, problems with the conduction system of the heart appear, the heartbeat becomes irregular, and cardiac output decreases;
• Mitral valve problems. Due to the thickening of the interventricular septum and other structures of the heart muscle, there is less and less room for blood to flow in the heart, which is why it has to move through the heart valves faster and with more force. As a result, the mitral valve (located between the left atrium and left ventricle) cannot close properly and blood can flow back through it. This disorder is called mitral regurgitation, and its complications can be arrhythmia and heart failure;
• Heart failure. A thickened ventricular septum and/or other parts of the heart muscle may become too stiff for the heart to fill normally with blood. If this causes cardiac output to decrease so much that circulatory system less blood is supplied than the body needs, heart failure is diagnosed. The main symptoms of heart failure are shortness of breath, which can occur even with little exertion, extreme fatigue and

Version: Directory of Diseases MedElement

Obstructive hypertrophic cardiomyopathy (I42.1)

general information

Short description

Isolated myocardial hypertrophy of unknown nature was first described in the second half of the 19th century by French pathologists N. Lionville (1869) and L. Hallopeau (1869). They noted the narrowing of the outflow tract of the left ventricle due to thickening of the interventricular septum and gave this disease the name "left-sided muscular conus stenosus".

Hypertrophic cardiomyopathy- myocardial disease of unknown etiology, inherited in an autosomal dominant way, characterized by myocardial hypertrophy of the left and (or) occasionally right ventricle, more often, but not necessarily, asymmetric, as well as severe disorders of diastolic filling of the left ventricle in the absence of dilatation of its cavity and causes of hypertrophy hearts.

Classification

Currently accepted hemodynamic classification of HCM.

By the presence of a gradient systolic pressure in the cavity of the left stomach

Daughter
Obstructive HCM- the presence of a systolic pressure gradient in the cavity of the left ventricle.

Hemodynamic variant of obstructive HCM
- With basal obstruction - subaortic obstruction at rest.
- With labile obstruction - significant spontaneous fluctuations in the intraventricular pressure gradient.
- With latent obstruction - obstruction occurs only during exercise and provocative pharmacological tests.

By pressure gradient(with obstructive form)

Stage 1 - pressure gradient less than 25 mm Hg

Stage 2 - less than 36 mm Hg

Stage 3 - less than 44 mm Hg

Stage 4 - from 45 mm Hg

The VOLV gradient is usually measured using Doppler echocardiography, which eliminates the need for cardiac catheterization in HCM (except in cases of suspected atherosclerotic lesions of the coronary arteries or heart valves).

Etiology and pathogenesis

HCM is an inherited disease that is transmitted as an autosomal dominant trait. A genetic defect occurs when there is a mutation in one of 10 genes, each of which encodes components of the cardiac sarcomere protein and determines the development of myocardial hypertrophy. Currently, about 200 mutations responsible for the development of the disease have been identified.

There are several pathogenetic mechanisms for the development of the disease:

- Hypertrophy of the interventricular septum. As a result of the resulting genetic defect in the myocardial sarcomere, disproportionate hypertrophy of the interventricular septum can develop, which in some cases occurs even during the period of embryonic morphogenesis. At the histological level, changes in the myocardium are characterized by the development of metabolic disorders in the cardiomyocyte and a significant increase in the number of nucleoli in the cell, which leads to the disintegration of muscle fibers and the development of connective tissue in the myocardium (the phenomenon of "disarray" - the phenomenon of "disorder"). Disorganization of cardiac muscle cells and replacement of the myocardium with connective tissue lead to a decrease in the pumping function of the heart and serve as the primary arrhythmogenic substrate, predisposing to the occurrence of life-threatening tachyarrhythmias.
- Obstruction of the output department of the left ventricle. Of great importance in HCM is the obstruction of the LV, which occurs as a result of disproportionate hypertrophy of the interventricular septum, which contributes to the contact of the anterior leaflet of the mitral valve with the interventricular septum and a sharp increase in the pressure gradient in the LV during systole.
- Violation of relaxation of the myocardium of the left ventricle. The prolonged existence of obstruction and hypertrophy of the interventricular septum leads to a deterioration in active muscle relaxation, as well as to an increase in the rigidity of the LV walls, which leads to the development of LV diastolic dysfunction, and in the terminal phase of the disease - systolic dysfunction.
- Myocardial ischemia. An important link in the pathogenesis of HCM is myocardial ischemia associated with the development of LV hypertrophy and diastolic dysfunction, which leads to hypoperfusion and increased myocardial fibrillation. As a result, thinning of the walls of the left ventricle, its remodeling and development of systolic dysfunction occur.

Epidemiology

Hypertrophic cardiomyopathy occurs with a frequency of 1:1000-1:500. It is generally accepted that it is most common among residents of Asia and the Pacific coast, especially in Japan. Men get sick more often than women. It is more common in young people, being a common cause of sudden cardiac death in them. About half of all cases of the disease are familial forms. The annual mortality from HCM is 1-6%.

Factors and risk groups

Risk factors for sudden death in hypertrophic cardiomyopathy:

Manifestation of the disease at a young age (up to 16 years),
- a family history of episodes of sudden death,
- Frequent syncope
- short episodes of ventricular tachycardia detected during 24-hour ECG monitoring,
- pathological change in the level of blood pressure during exercise.

Clinical picture

Symptoms, course

HCM can manifest at any age. The clinical picture is usually variable and patients may remain stable for a long period of time.

The classic triad of symptoms in hypertrophic cardiomyopathy includes exertional angina, dyspnea on exertion, and syncope. Pain in the chest is observed in 75% of patients with hypertrophic cardiomyopathy, classical exertional angina - in 25%.

Dyspnea and often accompanying chest pain, dizziness, syncope and pre-syncope usually occur with preserved LV systolic function. These symptoms are associated with the occurrence of diastolic myocardial dysfunction and other pathophysiological mechanisms (myocardial ischemia, LV obstruction and concomitant mitral regurgitation, AF).

Chest pain in the absence of atherosclerotic lesions of the coronary vessels, it can be both typical for angina pectoris and atypical.

Syncope and dizziness are characteristic, first of all, for patients with an obstructive form of HCM due to hemodynamic obstruction (decrease in the lumen of the LV). In most cases, they occur suddenly against the background of full health during a period of physical or emotional stress, however, they can also occur at rest. Most often, syncope is observed in young patients; in many of them, episodes of ventricular tachycardia and conduction disturbances are recorded during daily ECG monitoring.

A significant number of patients (5-28%) develop atrial fibrillation, which increases the risk of thromboembolic complications.

In the obstructive form of hypertrophic cardiomyopathy, the following symptoms are revealed:

Systolic murmur (crescendo-diminuendo), which is not conducted or weakly conducted to the carotid arteries and to the back. The noise is caused by obstruction during the expulsion of blood from the left ventricle (occurs in systole when the hypertrophied interventricular septum and the anterior leaflet of the mitral valve move towards each other);

The noise increases with a decrease in heart filling and a decrease in total peripheral vascular resistance (standing up from a squatting position, straining, taking nitroglycerin) and weakens with an increase in heart filling, an increase in total peripheral vascular resistance (in the supine position, sitting on squatting, when clenching fists);

Pulsation of the carotid arteries, a fast "jerky" pulse on palpation of the carotid arteries, which is a reflection of a very fast expulsion of blood in the first half of systole;

An intensified prolonged apex beat, which occupies the entire systole up to tone II, which is a sign of left ventricular hypertrophy;

On palpation of the apex beat in the position on the left side with a breath-hold on exhalation, a double rise is sometimes felt - IV tone is palpated, which is a reflection of increased atrial contraction with a decrease in left ventricular compliance;

On auscultation, the heart sounds are muffled, IV tone is detected.

Diagnostics

ECG in 12 leads.

Various ECG changes are recorded in 92-97% of patients, they serve as the earliest manifestation of HCM and may precede the development of myocardial hypertrophy, detected by echocardiography. Strictly specific ECG signs of HCM, as well as clinical ones, do not exist.
The most common are ST-segment changes, T wave inversion, signs of more or less pronounced left ventricular hypertrophy, deep Q waves, and signs of left atrial hypertrophy and overload. Less often, blockade of the anterior superior branch of the left leg of the His bundle and signs of hypertrophy of the right atrium, in isolated cases, of the right ventricle, are noted. Complete blockade of the legs of the bundle of His is not typical. Common ECG changes in HCM are negative T waves, in some cases in combination with ST segment depression, which are recorded in 61-81% of patients. Giant, over 10 mm deep, negative T waves in the chest leads are very characteristic of the apical form of this disease, in which they are of great diagnostic value. Changes in the terminal part of the ventricular complex in HCM are due to myocardial ischemia or small-focal cardiosclerosis. The detection of deep Q waves and negative T waves, especially with complaints of anginal pain, is a common cause of erroneous diagnosis of coronary artery disease and necessitates the differential diagnosis of HCM with this disease.

Holter ECG monitoring. Holter ECG monitoring for diagnosing rhythm and conduction disorders is indicated for patients with a high risk of sudden death, primarily with syncopal conditions, the presence of cases of sudden death in the family, as well as with clinical and ECG signs of myocardial ischemia. It is also advisable to use it to monitor the effectiveness of antiarrhythmic therapy.

Phonocardiography. Very characteristic, but non-specific, is a pathological increase in the III and especially IV heart sounds. An important sign of subaortic obstruction is the so-called late, not associated with the I tone, systolic murmur of a diamond-shaped or ribbon-shaped shape with an epicenter at the apex or in the III-IV intercostal space at the left edge sternum. It is carried out in the axillary region and less often on the base of the heart and vessels of the neck. Distinctive features of the noise, allowing to suspect obstructive HCM, are specific changes in its amplitude and duration during physiological and pharmacological tests aimed at increasing or decreasing the degree of obstruction and associated mitral insufficiency. This nature of the noise dynamics is not only of diagnostic value, but is also a valuable criterion for the differential diagnosis of HCM with primary lesions of the mitral and aortic valves. Noise may be preceded by an additional tone, which is formed when the mitral valve comes into contact with the interventricular septum. In some patients in diastole, a short, low-amplitude inflow murmur is recorded following the III tone, that is, relative mitral or occasionally tricuspid stenosis. In the latter case, the noise increases on inspiration. With a significant severity of obstruction to blood flow, a paradoxical splitting of the II tone is determined due to the lengthening of the period of left ventricular ejection in proportion to the magnitude of the systolic pressure gradient.

X-ray examination of the chest. The data of X-ray examination of the heart are not very informative. Even with significant myocardial hypertrophy, significant changes in the shadow of the heart may be absent, since the volume of the cavity of the left ventricle is not changed or reduced. In some patients, there is a slight increase in the arches of the left ventricle and left atrium and rounding of the apex of the heart, as well as signs of moderate venous pulmonary hypertension. The aorta is usually reduced.

Main ECHOCG signs :
- Asymmetric left ventricular myocardial hypertrophy but. The generally accepted criterion for HCM is an interventricular septal thickness of more than 15 mm with normal or increased LV posterior wall thickness. Given that the disease is genetically determined, the degree of hypertrophy may be different. However, the presence of symmetrical hypertrophy does not exclude the diagnosis of HCM.

- Obstruction of the outflow tract of the left ventricle. The hemodynamic systolic pressure gradient in the VOLZH is determined using Doppler scanning. A gradient of more than 30 mm Hg is considered diagnostically significant. (flow velocity in VOLZH - 2.7 m/s). Perform a test with physical activity to determine the degree of gradient in the VOLZH. The dobutamine test is not used due to the high risk of developing life-threatening arrhythmias.
- Anterior systolic movement of the anterior leaflet of the mitral valve. Dilatation of the left atrium, mitral regurgitation, and, in the terminal stage, LV dilatation are also often detected.

Stress echocardiography used to detect coronary heart disease associated with HCM, which has important prognostic and therapeutic value.

Radionuclide ventriculography as the most reproducible method for assessing the systolic and diastolic function of not only the left, but also the right ventricle, it is mainly used to monitor patients with HCM in dynamics and to evaluate the effectiveness of therapeutic measures.

Magnetic resonance imaging with It is the most accurate method for assessing the morphology of the heart, which plays a key role in the diagnosis of HCM. Thus, magnetic resonance imaging allows obtaining additional information compared to EchoCG on the distribution of hypertrophy in 20-31% of patients with HCM (F. Sardinelli et al., 1993; J. Posma et al., 1996) and provides measurements of the thickness of 97% of the segments of the left ventricle compared with 67% when using echocardiography (G. Pons-Llado et al., 1997). Thus, magnetic resonance imaging can serve as a kind of "gold standard" for assessing the prevalence and severity of myocardial hypertrophy in patients with HCM.

Positron emission tomography presents a unique opportunity for non-invasive assessment of regional perfusion and myocardial metabolism. Preliminary results of its use in HCM showed a decrease in the coronary expansion reserve not only in hypertrophied, but also unchanged in thickness segments of the left ventricle, which is especially pronounced in patients with anginal pain. Impaired perfusion is often accompanied by subendocardial ischemia.

When measuring pressure in the cavities of the heart The most important diagnostic and therapeutic value is the detection of the systolic pressure gradient between the body and the outflow tract of the left ventricle at rest or during provocative tests. This symptom is characteristic of obstructive HCM and is not observed in non-obstructive form of the disease, which does not allow excluding HCM in its absence. When registering the pressure gradient in the cavity of the left ventricle with respect to its outflow tract, it is necessary to make sure that it is due to subaortic obstruction to the expulsion of blood, and is not the result of a tight grip of the end of the catheter by the walls of the ventricle during the so-called "elimination" or "obliteration" of its cavity. Along with the subaortic gradient, an important sign of an obstruction to the expulsion of blood from the left ventricle is a change in the shape of the pressure curve in the aorta. As in the sphygmogram, it takes the form of a "peak and dome". In a significant proportion of patients with HCM, regardless of the presence or absence of a subaortic gradient, an increase in end-diastolic pressure in the left ventricle and pressure in the pathways of its inflow - in the left atrium, pulmonary veins , "pulmonary capillaries" and pulmonary artery. In this case, pulmonary hypertension is passive, venous. An increase in end-diastolic pressure in a hypertrophied left ventricle is due to a violation of its diastolic compliance, which is characteristic of HCM. Sometimes, in the terminal stage of the development of the disease, it is aggravated as a result of the addition of systolic dysfunction of the myocardium.

coronary angiography. It is performed with HCM and persistent retrosternal pain (frequent attacks of angina pectoris):

In persons over 40 years of age;
in persons with risk factors for coronary artery disease;
in individuals with an established diagnosis of coronary heart disease before invasive intervention (for example, septal myectomy or alcohol septal ablation).

Endomyocardinal biopsy of the left or right ventricle is recommended in cases where, after a clinical and instrumental examination, there are doubts about the diagnosis. When characteristic pathohistological signs of the disease are identified, a conclusion is made about the correspondence of morphological changes in the myocardium to the clinical diagnosis of HCM. On the other hand, the detection of structural changes specific to any other myocardial lesion (for example, amyloidosis) makes it possible to exclude HCM.

In the presence of Doppler echocardiography and magnetic resonance imaging, EMB is practically not used for diagnosing HCM.

Laboratory diagnostics

In order to exclude other most common cardiac diseases, it is necessary to conduct a biochemical blood test (lipid spectrum, biomarkers of myocardial necrosis, blood electrolyte composition, blood serum glucose), an assessment of the functional state of the kidneys, liver, and general clinical blood and urine tests.

Differential Diagnosis

Differential diagnosis is carried out with a number of diseases accompanied by the development of left ventricular hypertrophy, primarily "athlete's heart", acquired and congenital malformations, DCMP, and with a tendency to increase blood pressure - essential arterial hypertension. Differential diagnosis with heart defects accompanied by systolic murmur is of particular importance in cases of obstructive HCM. In patients with focal and ischemic changes on the ECG and anginal pain, the primary task is the differential diagnosis with coronary artery disease. With the predominance of signs of congestive heart failure in the clinical picture in combination with a relatively small increase in the size of the heart, HCM should be differentiated from atrial myxoma, chronic cor pulmonale and diseases that occur with a restriction syndrome - constrictive pericarditis, amyloidosis, hemochromatosis and sarcoidosis of the heart and restrictive cardiomyopathy.

Coronary artery disease. Most often, HCM has to be differentiated from chronic and less often acute forms of coronary artery disease. In both cases, anginal pain in the region of the heart, shortness of breath, cardiac arrhythmias, concomitant arterial hypertension, additional tones in diastole, small and large focal changes and signs of ischemia on the ECG can be observed. EchoCG is important for making a diagnosis, in which some patients IHD-specific violations of segmental contractility, moderate dilatation of the left ventricle and a decrease in its ejection fraction are determined. Left ventricular hypertrophy is very moderate and often symmetrical. The impression of a disproportionate thickening of the interventricular septum can be created by the presence of zones of akinesia due to postinfarction cardiosclerosis in the region of the posterior wall of the left ventricle with compensatory hypertrophy of the septal myocardium. At the same time, in contrast to asymmetric ventricular septal hypertrophy as a form of HCM, septal hypertrophy is accompanied by hyperkinesia. In cases of marked dilatation of the left atrium due to concomitant mitral regurgitation in coronary artery disease, dilatation of the left ventricle is invariably noted, which is unusual for patients with HCM. The diagnosis of HCM can be confirmed by the detection of signs of a subaortic pressure gradient. In the absence of echocardiographic data in favor of subaortic obstruction, differential diagnosis is much more difficult. The only reliable method for recognizing or excluding CAD in such cases is radiopaque coronary angiography. In middle-aged and older people, especially in men, it is necessary to keep in mind the possibility of combining HCM with coronary artery disease.

Essential arterial hypertension. For differential diagnosis, the most difficult is HCM, which occurs with an increase in blood pressure, which should be distinguished from isolated essential arterial hypertension, accompanied by left ventricular hypertrophy with disproportionate thickening of the interventricular septum. A significant and persistent increase in blood pressure, the presence of retinopathy, as well as an increase in the thickness of the intima and media of the carotid arteries, which is not typical for patients with HCM, testifies in favor of essential arterial hypertension. Particular attention should be paid to identifying signs of subaortic obstruction. In the absence of a subaortic pressure gradient, probable HCM, in contrast to essential arterial hypertension, is indicated by a significant severity of asymmetric hypertrophy of the interventricular septum with an increase in its thickness by more than 2 times compared to the posterior wall of the left ventricle, as well as the detection of HCM in at least one of 5 adult blood relatives. On the contrary, in the absence of signs of HCM in 5 or more members of the patient's family, the probability of this disease does not exceed 3%.

When left ventricular hypertrophy is combined with systolic murmur, it is necessary to conduct a differential diagnosis of obstructive HCM with heart defects, primarily mitral valve insufficiency, valvular and subvalvular membranous stenosis of the aortic orifice, aortic coarctation, and ventricular septal defect. An important differential diagnostic value in this case is the nature of the dynamics of the amount of backflow of blood according to auscultation, FCG and Doppler echocardiography under the influence of changes in preload and afterload of the left ventricle with the help of a change in body position, Valsalva maneuver and the introduction of vasopressor and vasodilator drugs.

Unlike HCMP, when rheumatic mitral insufficiency the volume of regurgitation to the left atrium increases with an increase in blood pressure, that is, obstruction of expulsion, and decreases with a decrease in venous inflow in a standing position or after inhalation of amyl nitrite. A family history, the presence of anginal pain, focal and ischemic changes on the ECG testify in favor of the diagnosis of HCM. Confirm the diagnosis allows the detection of signs of subaortic obstruction with Doppler echocardiography.

Certain difficulties may arise in the differential diagnosis of HCM and mitral valve prolapse. In both diseases, there is a tendency to palpitations, interruptions, dizziness and fainting, "late" systolic murmur over the apex of the heart and the same nature of its dynamics under the influence of physiological and pharmacological tests. At the same time, mitral valve prolapse, in contrast to HCM, is characterized by a lesser severity of left ventricular hypertrophy and the absence of focal ECG changes. The final diagnosis can be made on the basis of Doppler echocardiography, including transesophageal.

Valvular stenosis of the aortic orifice. In some cases, the epicenter of the systolic murmur of valvular stenosis of the aortic orifice is determined at the Botkin point and above the apex of the heart, which may resemble the auscultatory picture of obstructive HCM. Both diseases are equally characterized by anginal pain, shortness of breath, syncope, signs of left ventricular hypertrophy, changes in the ST segment and T wave on the ECG, as well as an increase in the thickness of the left ventricular myocardium with unchanged or reduced sizes of its cavity during EchoCG and ACG. To distinguish stenosis of the aortic orifice helps to determine the characteristics of the pulse, conducting systolic murmur to the vessels of the neck, the presence of post-stenotic expansion of the ascending aorta and signs of fibrosis or calcification aortic valve with radiography and echocardiography, as well as changes in the sphygmogram in the form of a "cockscomb". The diagnosis of aortic stenosis can be confirmed by the detection of a systolic pressure gradient at the valve level during Doppler echocardiography and cardiac catheterization.

A more difficult task is the differential diagnosis of obstructive HCM and membranous subaortic stenosis. Family history, the characteristic shape of the sphygmogram curve, and later onset of systolic aortic valve occlusion on echocardiography may support HCM, while concomitant aortic regurgitation, a common complication of this congenital malformation, indicates probable membranous aortic stenosis. Doppler echocardiography and invasive examination help to clarify the diagnosis, allowing to determine the localization and nature (fixed or dynamic) of the obstruction to ejection in the left ventricle.

Sick aortic coarctation, as well as HCM, there are complaints of shortness of breath, dizziness and cardialgia that occur at a young age and are combined with systolic murmur in the precordial region and signs of left ventricular hypertrophy on ECG and echocardiography. Recognition of these diseases usually does not cause difficulties and is possible already at the stage of clinical examination if an increase in blood pressure is pathognomonic for aortic coarctation. upper limbs and its decline to the lower ones. In doubtful cases, the data of magnetic resonance imaging and radiopaque aortography allow confirming the diagnosis of congenital heart disease.

Ventricular septal defect. In asymptomatic young patients with a rough systolic murmur in the III-IV intercostal space at the left edge of the sternum and signs of left ventricular hypertrophy, it is necessary to conduct a differential diagnosis of obstructive HCM with a ventricular septal defect. Distinctive features of this congenital malformation during non-invasive examination are "heart hump" and systolic trembling at the place of listening to the noise, its connection with the I tone, as well as a noticeable increase in the pulmonary artery arch on radiographs of the heart. The final diagnosis can be made using Doppler echocardiography, and in especially difficult cases, an invasive examination of the heart.

Complications

The course of the disease can be complicated by the development of such complications as:

- sudden cardiac death (SCD)
- thromboembolism
- progression of chronic heart failure (CHF).

Treatment

TO general activities include the limitation of significant physical activity and the prohibition of sports that can cause exacerbation of myocardial hypertrophy, an increase in the intraventricular pressure gradient and the risk of VS. To prevent infective endocarditis in situations associated with the development of bacteremia, with obstructive forms of HCM, antibiotic prophylaxis is recommended, similar to that in patients with heart defects.

The basis of drug therapy for HCM is drugs with a negative inotropic effect: β-blockers and calcium channel blockers (verapamil).

β-blockers became the first and remain to this day the most effective group of drugs used in the treatment of HCM. they should be prescribed to patients regardless of the severity of the intraventricular pressure gradient at rest. It is preferable to refrain from prescribing β-aope-noreceptor blockers with intrinsic sympathomimetic activity (pindolol, oxprenolol). Propranolol is prescribed at a dose of 240-320 mg per day or more (the maximum daily dose is 480 mg), metoprolol is prescribed at a dose of 200 mg per day or more. Cardioselective blockers of beta-adrenergic receptors in hypertrophic cardiomyopathy do not have advantages over non-selective ones, since at high doses, selectivity is practically lost.

In case of contraindications to the appointment of beta-blockers or incomplete resolution of symptoms, an alternative may be calcium channel blockers. Among the calcium channel blockers, the drug of choice is verapamil (Isoptin, Finoptin). It provides a symptomatic effect in 65-80% of patients. When prescribing calcium channel blockers, maximum caution is required in the presence of severe hypertrophy and a very high filling pressure of the left ventricle. It should be borne in mind that calcium channel blockers, including verapamil, with long-term use can increase diastolic pressure and reduce cardiac output. Treatment with verapamil should begin with the appointment of low doses - 20-40 mg 3 times a day, gradually increasing to a daily dose of 240-320 mg or more. Clinical improvement when taking verapamil is accompanied by an increase in exercise tolerance.

For the treatment of arrhythmias, antiarrhythmic drugs are used, of which the most effective are disopyramide and amiodarone. Disopyramide (ritmilen), which belongs to class IA antiarrhythmics, has a pronounced negative inotropic effect; in patients with HCM, it can reduce the level of left ventricular outflow tract obstruction and positively affects the structure of diastole. The initial dose is usually 400 mg / day with a gradual increase to 800 mg. In this case, it is necessary to control the duration of the Q-T interval according to the ECG.
Amiodarone is the only drug against which the elimination of ventricular tachyarrhythmias, a decrease in the incidence of sudden death and an improvement in the prognosis of the disease has been noted to date. Amiodarone is prescribed at a daily dose of 1200 mg for 5-7 days, then at a daily dose of 800 mg and 600 mg during the 2nd and 3rd weeks of treatment, followed by a transition to a maintenance daily dose of 200 mg.

When treating HCM with symptoms of heart failure, the following points should be considered:
diuretics are contraindicated which, although effective in reducing pulmonary congestion, can cause hypovolemia, which can increase outflow tract obstruction in patients! Too long use of diuretics can cause a decrease in stroke volume and cardiac output.
Vasodilators (nitroglycerin, sodium nitroprusside) have limited use due to the possible risk of severe hypotension and a decrease in the size of the left ventricular cavity, which can worsen the patient's condition.
Inotropic agents aimed at stimulating systolic output (cardiac glycosides and pressor amines), may have an unfavorable hemodynamic effect - they increase the obstruction of the outflow tract and do not reduce elevated end-diastolic pressure, they can cause the development of asystole. However, digoxin may be used in patients with diastolic dysfunction and atrial fibrillation to decrease heart rate and/or restore sinus rhythm.
Drugs of choice for the treatment of CHF may be ACE inhibitors due to their ability to block the renin-angiotensin system and cause regression of left ventricular hypertrophy.

In the absence of a clinical effect from active drug therapy in symptomatic patients of III-IV functional class according to the classification of the New York Heart Association with severe asymmetric IVS hypertrophy and a subaortic pressure gradient at rest equal to 50 mm Hg. Art. and more, surgical treatment is indicated.
The classic technique is transaortal septal myectomy proposed by Agmorrow. The operation provides a good symptomatic effect with a complete elimination or a significant decrease in the intraventricular pressure gradient in 95% of patients and a significant decrease in LV end-diastolic pressure in 66% of patients.
In some cases, if there are additional indications to reduce the severity of obstruction and mitral regurgitation, valvuloplasty or mitral valve replacement with a low-profile prosthesis is performed simultaneously.

In recent years, there has been growing interest in studying the possibility of using as an alternative to surgical treatment of patients with obstructive HCM sequential two-chamber pacing with a shortened atrioventricular delay. The change in the sequence of propagation of the wave of excitation and contraction of the ventricles, which first covers the apex and then the IVS, caused in this way, leads to a decrease in the subaortic gradient due to a decrease in the regional contractility of the IVS and, as a result, the expansion of the LV outflow tract.

Other alternative method treatment of refractory obstructive HCM is transcatheter alcohol septal ablation The technique involves infusion through a balloon catheter into the perforant septal branch of 1-3 ml of 95% alcohol, resulting in an infarction of the hypertrophied IVS, which captures from 3 to 10% of the LV myocardial mass (up to 20% of the IVS mass). This leads to a significant decrease in the severity of outflow tract obstruction and mitral insufficiency, objective and subjective symptoms of the disease. At the same time, in 5-10% of cases, it becomes necessary to implant a permanent pacemaker due to the development of atrioventricular block high degree. In addition, to date, a positive effect of transcatheter ablation on prognosis has not been proven, and operative mortality (1-2%) does not differ from that during septal myectomy, which is currently considered the “gold standard” for the treatment of patients with HCM with severe symptoms and obstruction. outflow tract of the left ventricle, resistant to pharmacotherapy.

Forecast

The prognosis is most favorable with a long asymptomatic course of the disease and an uncomplicated family history, especially in the apical form of HCM. In some such cases, the disease may not affect life expectancy.

Most patients with HCM die suddenly, regardless of how long ago the disease was. The poor prognosis in children, most of whom are asymptomatic, is associated with a positive family history of sudden death. In adolescents and persons of young and middle age (from 15 to 56 years), the main factor that aggravates the prognosis is susceptibility to fainting. In older patients, shortness of breath and pain in the heart area during physical exertion are prognostically unfavorable.

There are 5 main variants of the course of the disease and outcomes:
- stable, benign course;
- sudden death;
- progressive course - increased shortness of breath, weakness, fatigue, pain syndrome (atypical pain, angina pectoris), the appearance of syncope, disorders of LV systolic dysfunction;
- "final stage" - further progression of the phenomena of congestive heart failure associated with remodeling and LV systolic dysfunction;
- the development of atrial fibrillation and related complications, in particular thromboembolic.

Prevention

Prevention of the disease is to identify it at an early stage, which allows you to start early treatment of the disease and prevent the development of severe myocardial hypertrophy. EchoCG must be performed without fail in the "blood" (genetic) relatives of the patient. All other persons are shown a detailed examination in the presence of manifestations similar to the disease: fainting, angina pectoris, etc. Screening (all in a row) ECG and EchoCG during the annual medical examination are also useful. In patients with obstructive HCM, it is also necessary to prevent infective endocarditis (antibiotic prophylaxis, etc.), since the presence of obstruction creates conditions for the development of this life-threatening disease.

Information

Information

1. Treatment of heart failure. Recommendations of the working group on the study of heart failure of the European Society of Cardiology. Rus. honey. magazine Appendix. 1999.
2. Amosova E.N. Cardiomyopathy. Kyiv: "Book Plus", 1999; 421 p.
3. Kushakovsky M.S. Chronic congestive heart failure. Idiopathic myocardiopathies. St. Petersburg: "Foliant", 1998; 320 p.
4. Moiseev V.S., Sumarokov A.V., Styazhkin V.Yu. Cardiomyopathy. M.: Medicine 1993; 176 p.
5. Guide to outpatient cardiology, edited by Yu. N. Belenkov, R. G. Oganov, GEOTAR-Media publishing house, - 2007.-400 p.
6. Polyakov V.P., Nikolaevsky V.N., Pichko G.A. Non-coronary and infectious diseases of the heart (modern aspects of the clinic, diagnosis, treatment): Monograph.-Samara, 2010,-355p.
7. Internal diseases according to Tinsley R. Harrison / Ed. E. Fauci, J. Braunwald, K. Isselbacher, J. Wilson, J. Martin, D. Kasper, S. Hauser and D. Longo: In 7 vols. - M.: Practice -Mc-Grow_Hill, 2005.
8. Clinical guidelines. Cardiology / Ed. Yu.N. Belenkova, R.G. Oganov. - M.: GEOTAR-Media, 2007.
9. B. Griffin, E. Topol "Cardiology" Moscow, 2008
10. Kovalenko VN, Nesukai EG Non-coronary heart disease: a practical guide / Ed. V. N. Kovalenko. K .: "Morion", 2001. - 480 p.

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