Myocardiodystrophy

Cardiomyopathy is myocardium affection of noncoronary and noninflammatory nature, associated with its dysfunction.

Dilated cardiomyopathy is characterised by the distension and disbalance in contraction of the left ventricle of heart or of both ventricles. It can be idiopathic, family/genetic, viral, immune, alcoholic, toxic.

Hypertrophic cardiomyopathy is characterised by left or right ventricle enlargement which tends to be asymmetric and includes interventricular septum. As a rule, the volume of the left ventricle of heart appears normal or lowered.

Restrictive cardiomyopathy is characterised by the lowered filling and lowered diastolic volume of one or both ventricles with normal or close to normal contractive ability and normal thickness of a cardiac wall.

Arrythmogenic cardiomyopathy of the right ventricle is characterised by progressive fibrozno-fatty replacement of a myocardium of the right ventricle, originally with typical regional and after global function impairment of the right ventricle and some part of the left ventricle with relative preservation of a septum. It is usually a family illness. Arrhythmia and sudden death are common, especially in a youth.

The most often disease to be found is dilated cardiomyopathy (DC) – the disease of a myocardium characterised by the development of enlargement of heart, with occurrence of systolic dysfunction, but without enlargement of wall thickness.

DC is characterised by the development of progressive cardiac insufficiency, heart [cardiac] rate disturbance and disorder of conduction, (thrombo)embolism, sudden death. The criterion of disease is considered to be the decrease in left ventricular ejection fraction below 45 % and the size of a left ventricular cavity in diastole more than 6 cm.

Aetiology DC is various. As a matter of fact, this disease is a syndrome developing in an outcome of various conditions, striking a myocardium. This is rather widespread disease – its frequency reaches 1:2500 – the third reason on frequency of cardiac insufficiency. DC can be a consequence of infectious diseases (as the outcome of myocarditis, or it can develop with underlying myocarditis), acute intoxication (alcohol-induced heart injury, drug-induced medicamentous poisonings, metaltoxicosis: cobalt, mercury, arsenic, lead).

Alcohol-induced heart injury is considered to be the most frequent reason for DC in usual medical practice, but there are no definite proofs that in this case only alcohol causes heart injury. Probably, thiamine insufficiency typical for alcoholics has more importance.

Idiopathic DC occurs in 20-35 % of cases. It is connected with more than 20 loci and genes, that is it is genetically heterogeneous. It is usually autosomal -prepotent, but there are also H-linked autosomal -recessive and mitochondrial forms. It has been revealed that in certain cases of DC the mutations of the same genes which define the development of hypertrophic cardiomyopathy (α-aktin, α-tropomiozin, troponin) can occur. Cases of conversion of hypertrophic cardiomyopathy into dilated cardiomyopathy have been described.

Eccentric hypertrophy and dilatation of the ventricular cavity of heart are morphological characters of DC. The left regions are usually struck, in case of hereditary forms the right ventricle is also struck in 1,7 % of cases. The disseminated sclerosis and hydropic [vacuolar] degeneration of myocardium dystrophy but without inflammatory changes reveal histologically. The inflammatory centres can be found out in the event that a cause of illness was myocarditis. A myocardium sclerosis is usually disseminated, but focal changes are also possible.

Idiopathic DC usually develops at young age. Clinical presentations of dilated cardiomyopathy, irrespective of its reason, can be reduced to the following syndromes:

• heart failure ( of both left ventricle, and right ventricle, however total " congestive” heart failure occurs more often;
• cardialgin, and also stenocardia attacks (at half of patients);
• heart [cardiac] rate disturbance (atrial [auricular] fibrillation, ventricular premature beats are frequent ) and myocardial conduction (blockade of legs of a bunch of Gisa);
• (thrombo)embolism.

Objective data of DC: increase in the size of heart – percussion borders are expanded extensively, the apical thrust is displaced to the left-downwards, diffuse. At auscultation the heart sounds are muffled, «the gallop rhythm» at the expense of III and IV tones is possible. The systolic murmur is often listened owing to relative mitral and tricuspid insufficiency, and there can also occur jugular venous distention, hypostases, large liver mass.

Patients die either suddenly, owing to heart [cardiac] rate disturbance, or as a result of progressive heart failure.

The therapy of dilated cardiomyopathy is symptomatic. Before the discovery of stem cells the heart transplantation was the only method of curative treatment. With the advent of methods of regenerative medicine patients have received real possibility to find the lost health again. The treatment principle of dilated cardiomyopathy by means of stem cells transplantation consists in introducing genetic factors coding fibers which regulate cardiac muscle reduction (at idiopathic form of DC) into sick heart. It happens at the expense of stem cells’ fusion with cardiac hystiocyte. Besides, the regeneration of contractile muscle function of a myocardium is possible owing to formation of new cardiac hystiocytes from the introduced stem cells.

Clinical example. Patient F, 19 years, was waiting for a heart transplantation with the diagnosis of dilated cardiomyopathy . On account of absence of donor heart, he was assigned by the National institute of surgery and transplantology in the name of Shalimov on treatment in the Institute of cellular therapy. The family anamnesis showed the death of his sister at the age of 11 from acute cardiovascular insufficiency . The main complaints of the patient were breathlessness arising even at small physical activity, hypostases by the end of day. Ejection fraction – 26 %. The back wall of the left ventricle of heart practically does not contract.

The haemopoetic stem cells of a liver were transplanted to the patient. In 3 months the ejection fraction increased to 44 %, the contractions of a back wall of left ventricle appeared. The patient feels well, stands usual physical activity easily. In 6 months his condition was stable, the ejection fraction – 44 %. The patient is under medical supervision of the cardiologist.