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Cardiomyopathy.

Cardiomyopathies are diseases of the myocardium accompanied by cardiac dysfunction. In accordance with the classification proposed by the WHO expert committee (1995), the following are distinguished: dilated cardiomyopathy; hypertrophic cardiomyopathy; restrictive cardiomyopathy; arrhythmogenic right ventricular cardiomyopathy; unclassified cardiomyopathy; specific cardiomyopathy.

Dilated cardiomyopathy (DKM) is the most common form of cardiomyopathy, its prevalence reaches 40 cases per 100,000 population. The incidence rate is 5-8 cases per 100,000 population per year. DKM appears at the age of 18-50 years, is more common in men than in women (2.5: 1 ratio).

Approximately 30-40% of patients with DCM revealed a familial form of DCM. At the same time, the DCM with an autosomal dominant form of inheritance prevails, less often there are DCM with X-linked, autosomal recessive and mitochondrial types of transmission. Two main autosomal dominant forms of DCM were distinguished: "pure" DCM and DCM, combined with a lesion of the cardiac conduction system (DCMP). Pure DKM and DKMPS are characterized by genetic heterogeneity. At present, 10 loci are identified that are responsible for the development of pure DCM and mapped into 1q32, 2q33, 2q35, 4q12, 5q33, 9q13-22, 10q21-23, 14q11.15q2, and 15q14. Products 7 of 10 genes are already known: actin (15q14), desmin (2q35), 5-sarkoglikan (5q33), P-sarkoglikan (4q12), cardiac troponin T (1q32), P-heavy chain of myosin (14q11) and a- tropomyosin (15q2). Genes mapped in chromosomes 1p1-1q1, 2q14-21, 3p22-25, 6q23 are responsible for the development of DCMPS. Of these, only one gene has been identified so far. This is lamin A / C on chromosome 1q21.

DKM with the X-linked inheritance is due to mutations in the Xp21 gene, which is responsible for the synthesis of dystrophin, or in the Hp28 gene, which encodes the tafazzin protein. Skeletal myopathies develop in almost all forms of DCM (Table 16.1).

In most cases, DCM genetic causes of the disease can not be identified. It is believed that the long-term effects of damage to the heart muscle may play a role in the development of DCM

Table 16. Genetic characteristics of dilated cardiomyopathy (according to JATowbin, NEBowles, 2002) DKM - dilated cardiomyopathy; ** DKMPS - Dila
Phenotype Chromosomal Gene Skeletal
locus myopathy
Net DKM * 15q14 Actin Myopathy Niemann
2q35 Desmin Desmine
myopathy
5q33 8-sarkoglikan Muscular Dystrophy
limbs
1q32 Troponin I ?
14q11 R-heavy chain ?
myosin
15q2 a-tropomyosin Myopathy Niemann
Mhdnc Cycle enzymes Mitochondrial
Krebs myopathy
DCMPS ** 1q21 Lamin A / C Muscular Dystrophy
Emery — Dreyfuss
X-linked Xp21 Distrofin Muscular Dystrophy
DKM Duchenne — Becker
Xp28 G4.5 (tafazzin) Bart's syndrome
Tational cardiomyopathy combined with affection of the cardiac conduction system

toxic products, such as alcohol, viruses, immune processes, etc.

Clinically, DCM is manifested by impaired systolic function, increasing heart failure, atrial and (or) ventricular arrhythmias. Sudden cardiac death can occur at any stage of the disease. Macroscopically, the heart is enlarged due to dilatation of all four chambers of the heart and, to a lesser extent, myocardial hypertrophy, although observations are described in which the myocardial mass reached 900 g. sclerosis. The valves of the heart and coronary arteries do not have any specific features. However, due to the expansion of the heart cavities, relative mitral insufficiency occurs. Microscopically, they reveal, firstly, the uneven hypertrophy of most cardiomyocytes, but about a quarter of the muscle cells look unchanged, and, secondly, different variants of myocardial stroma sclerosis.

The prognosis of the disease is serious - five-year survival is 50%. Causes of death: progressive heart failure, severe arrhythmia, thromboembolic complications.

Currently, arrhythmogenic right ventricular cardiomyopathy (APKM) is considered as a separate form of cardiomyopathy, before it was attributed to DKM variants. The peak of the development of APKM falls on the age of 16-35 years. Analysis of patients with APKM revealed genetic causes of the disease. In the autosomal dominant type of transmission, defects were found in 7 genes of different chromosomes: 14q23 — q24, 1q42 — q43, 14q12 — q22, 2q32.1 — q32.2, 3p23, 10p12 — p14, 10q22.3. It is assumed that mutations affect the genes involved in the processes of apoptosis, the reception of viruses, the regulation of ion exchange. In an autosomal recessive type of transmission, a defect was detected in the chromosomal locus 17q21 encoding placoglobin. It is accompanied by the development of a syndrome characterized by a combination of APKM with palmoplantar keratoderma and gun hair.

Macroscopically, the most pronounced changes in the right ventricle. The wall of the right ventricle is dramatically thinned, becomes translucent ("parchment heart"), saccular aneurysms are often found in the apex, the back wall, funnel (APCM triad).
Microscopically revealed severe atrophy of the myocardium of the right ventricle and replacement of cardiomyocytes with adipose or fibro-adipose tissues, which starts from the side of the epicardium. The progressive decline of cardiomyocytes is due to the activation of apoptosis. In 75% of cases, inflammatory cellular infiltration with CD43 + T-lymphocytes is found, which suggests the importance of chronic myocarditis in the morphogenesis of APM, which often results in sudden cardiac death.

Hypertrophic cardiomyopathy (HCM) is characterized by disproportionate hypertrophy of the left ventricle of the heart and rarely of the right ventricle. The disease is characterized by severe "muscular" hypercontracting of the heart and poor diastolic relaxation of the ventricles. The prevalence of HCM is estimated at 0.2%. Sporadic cases of HCM are less common than the familial form with an autosomal dominant type of transmission and reduced gene penetrance. The peak of the development of clinical manifestations is observed at the age of 10-25 years. At present, 10 loci responsible for the development of HCM, mapped in 14q11.2 — q12, 1q3, 15q2, 11p11.2, 7q3, 3p21.2, 3p21.3, 12q23 — q24.3,15q14, 2q31, have been studied. The products of these genes are already known (see Table 16.2).

Macroscopically with HCM revealed severe myocardial hypertrophy with a predominant increase in the interventricular septum (asymmetric septal hypertrophy). Rarely, symmetric myocardial hypertrophy occurs. Due to

Table 16. Genetic characteristics of hypertrophic cardiomyopathy (according to JATowbin, NEBowles, 2002)

Phenotype Chromosomal Gene
locus
Hypertrophic 14q11 R-heavy chain of myosin
cardiomyopathy 1q32 troponin T
12q23 troponin I
15q2 a-tropomyosin
11p11 myosin associated with protein C
3p21 main light chain of myosin
3p21 myosin regulatory light chain
2q31 titin
HCM in combination 7q3 AMP-activated protein kinase
with a syndrome Mhdnc Krebs cycle enzymes
Wolf—
Parkinson—
White (WPW)
hypertrophy of the walls of the left ventricle, its cavity takes the form of a banana. At the base of the heart, the interventricular septum hypertrophy is usually more pronounced than in other parts. With a pronounced thickening of the septum at the level of the mitral valve, systolic discharge of blood from the left ventricle of the heart into the aorta is disturbed. Developed obstructive HCM. Microscopically detected chaotic arrangement of beams sharply hypertrophied cardiomyocytes. In the interstitium sclerotic changes with varying degrees of severity in different parts of the myocardium.

Complications of HCM: atrial fibrillation with the formation of blood clots and subsequent thromboembolism, increasing heart failure. Sudden cardiac death may develop.

Restrictive cardiomyopathy is characterized by endomyocardial fibrosis, which develops in one or both ventricles of the heart, and a violation of the filling of the ventricular cavities. Defeat of atrioventricular valves is often observed without changes in the outflow paths from the ventricles. As the disease progresses, obliteration of the ventricular cavities may occur. Restrictive cardiomyopathy can be idiopathic, it also includes endomyocardial fibrosis, Leffler fibroplastic parietal endocarditis with / without eosinophilia, endocardial fibroelastosis. Endomyocardial fibrosis is believed to be common only in tropical areas, and Leffler's endocarditis is moderate. The etiology of these two diseases is unknown. Typical cardiac changes are identical.

The heart is enlarged, the endocardium is thickened to a few millimeters, especially along the flow path, in the apex and part of the outflow path from the left ventricle. In cases of involvement of the right ventricle, the apex in the area under the tricuspid valve is characteristic. The mitral valve, especially the back, sclerotic. In both ventricles, and also in auricles thrombi sometimes appear. The coronary arteries of the heart are not changed. Microscopically reveal layers of thickened endocardium. The surface layer is represented by connective tissue, under it is a zone of granulation tissue with eosinophilic infiltration. Often, calcification and, sometimes, ossification of the endocardium are detected. Cardiomyocytes in a state of hypertrophy; sometimes inflammatory infiltration is revealed, interstitial myocardial fibrosis is characteristic. Endocardial fibroelastosis is rare, usually in children under 2 years of age, and combined with congenital heart disease. The etiology of the disease is unknown.

Unclassified cardiomyopathies include several diseases that did not fall into other categories of cardiomyopathies. This group includes forms with minimal cardiac changes that progress very slowly, as well as idiopathic hypertrophy and left ventricular aneurysms of unknown etiology, which are found in Africa.

Specific cardiomyopathies include myocardial diseases of known etiology or associated with lesions of other systems. Myocardial diseases caused by systemic or pulmonary hypertension, coronary heart disease, valvular heart disease or congenital heart disease are excluded from this group if the degree of impairment of contractile function does not exceed the severity of these diseases. The following forms of specific cardiomyopathies are distinguished: infectious, metabolic, with systemic diseases, family-genetic, toxic, immunological.

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Cardiomyopathy.

  1. Cardiomyopathy. Hypertrophic cardiomyopathy (code 142.0)
    The term "cardiomyopathy" refers to a state of unknown etiology, the most important signs of which are cardiomegaly and heart failure; this name excludes heart disease resulting from valve damage, impaired coronary blood flow, and hypertension in the large and small circulation. Etiology. Clinical and anatomical forms. Prospective
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  3. E.N. Amosov. Cardiomyopathy 1999
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  4. Cardiomyopathy
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  6. Cardiomyopathy
    The term "cardiomyopathy" was first used in 1957 to refer to a group of myocardial diseases of unknown etiology. In 1972, the following definition of cardiomyopathy was given: "Cardiomyopathy is an acute, subacute or chronic lesion of the heart muscle of unknown or unclear etiology, often combined with a lesion of the endocardium, and sometimes the pericardium." This definition is accepted.
  7. CARDIOMYOPATHY.
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  8. Cardiomyopathy
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  9. Tacysubo cardiomyopathy
    Definition Tacocubi cardiomyopathy is a transient balloon-like expansion of the middle part of the apex of the heart (apical ballooning), accompanied by transient regional systolic dysfunction with simultaneous hyperkinesia of the basal segments of the left ventricle in the absence of coronary artery stenotic lesions. For the first time, cardiomyopathy was also described in 1990 by Japanese researchers H. Satoh.
  10. CARDIOMYOPATHY
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  11. CARDIOMYOPATHY
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  12. Dilated cardiomyopathy
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  13. RESTRICTIVE CARDIOMYOPATHY
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  16. Non-compact LV cardiomyopathy
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    The concept of ischemic cardiomyopathy was proposed in 1969, when Raftery and colleagues identified a causal relationship between coronary artery disease and congestive cardiomyopathy. In other words, in the cases described, a marked cardiomegaly with manifestations of congestive HF was observed, as is the case with typical DCM, and only atherosclerotic lesion of the coronary arteries indicated its ischemic genesis. Term
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