The development of methods of treatment of chronic cardiac insufficiency under dilation cardiomyopathy in children is an actual issue of children cardiology. The article presents complex clinical biochemical results of examination of children with chronic cardiac insufficiency under dilation cardiomyopathy. the complex therapy included inhibitors of angiotensin converting enzyme and P-adrenoceptor antagonists. On the basis of analysis in blood serum concentrations of matrix metalloproteinase, matrix metalloproteinase tissue inhibitor-1, content of single components of apoptosis, superoxide dismutase and total nitrogen oxide the alterations of these biologically active agents in blood serum of children with different stage of circulatory disturbance prior and after application of cardio-protection therapy. It is demonstrated that amelioration of clinical conditions of patients with circulatory disturbance stage I-IIA is followed by tendency to normalization of content of matrix metalloproteinase, matrix metalloproteinase tissue inhibitor-1 and decreasing of degree of apoptosis cell destruction. This trend can be caused by capacity of inhibitors of angiotensin converting enzyme and P-adrenoceptor antagonist to suppress increased synthesis of matrix metalloproteinase and processes of apoptosis due to decreasing of degree of hypoxic damage of cardiac hystiocytes. In children with circulatory disturbance stage IIB-III resistance to the applied therapy can be a consequence of increased endogenous production of nitrogen oxide.

The data of examination of 32 children with a diagnosis of hypertrophic cardiomyopathy (HCM), and 2 patients with hypertension are presented. The results of long-term observation of the dynamics of blood pressure have been followed up and blood plasma renin activity has been detected. M235T angiotensinogen gene polymorphism (AGT) and I/D polymorphism of the ACE gene were studied. In observed patients TT polymorphism and T allele of the AGT gene occurred more frequently than in the control group. In the obstructive form of HCM D-allele detected significantly more frequently than in non-obstructive one. The data indicate the possibility of development of hypertension in patients with HCM. A supposed genetic risk factor is the presence of the TT genotype of AGT.

In 55 children with dilated cardiomyopathy polymorphism in the gene structure of the renin-angiotensin system (RAS): G83A polymorphism of the renin gene (REN), M235T angiotensinogen gene polymorphism (AGT), angiotensin converting enzyme (ACE) I/D polymorphism, angiotensin II type 1 receptor A1166C gene polymorphism (AGTR1), A3123S = angiotensin II type 1 receptor gene polymorphisms (AGTR2), has been studied. The association of the severity of left ventricular dilatation with the A allele and AA = renin gene polymorphism (with G83A) and T allele and the TT polymorphism of angiotensinogen gene (M235T) has been revealed. The severity of DCM was shown to be also dependent on I/D polymorphism of the ACE gene.

Іn the article the state of the processes of cell death іn the formation of restrictive syridrome іn childreri is preserited. The role of biomarkers of a mitochondrial and membrane component of apoptosis in disturbing diastolic heart function is proved convincingly. Diastolic dysfunction of the heart with restrictive cardiomyopathy was shown to be accompanied by a high content of cytochrome-C in patients' blood, indicating the importance of hypoxia in the induction of apoptosis. A quantitative description of the induction of cell death depending on the violation of the diastolic process has been done. The changes to the content of the molecular agents of apoptosis in patients were revealed to be accompanied by a high concentration of nitric oxide, which leads to the activation of matrix metalloproteinases, increased collagenolytic processes and fibrosis of myocardial tissue. The issues of biochemical interaction in the development of pathology of diastole are discussed.

The data of studies of gene polymorphisms of angiotensin converting enzyme (ACE) and methylenetetrahydrofolate reductase (C677T) in 55 children with dilated cardiomyopathy (DCMP) are reported. For patients with DD genotype of ACE the debut of the disease at school age and more frequently observed slow progressive and relapsing course of the disease were established to be typically occur. In patients with II genotype benign course of DCMP was observed more frequently. Patients with DCMP, homozygous and heterozygous for the T-allele of the methylenetetrahydrofolate reductase gene have more pronounced changes in the structural and functional parameters of the heart and a greater risk of adverse outcome than compared with those homozygous for the C allele

Hypertrophic cardiomyopathy (HCMP) is a genetically determined myocardial disease, characterized by massive hypertrophy of the myocardium of the left and/or (rarely) the right ventricle, often associated with obstruction of the left ventricular outflow tract and diastolic dysfunction. The course of disease can be complicated by development of various cardiac arrhythmias.  It was reported that severity of HCMP course depends at certain degree on polymorphism of candidate genes, including genes of the renin angiotensin system (RAS). Influence of RAS genes polymorphism on the frequency and character of cardiac arrhythmias in childhood is almost not studied. Aim : to determine the influence of RAS genes polymorphism on the prevalence and structure of cardiac arrhythmias in children with HCMP. Patients and methods : analysis of influence of RAS genes polymorphism on the prevalence and structure of cardiac arrhythmias was performed in 32 children with HCMP. All the patients were carried out ECG, cardiac ultrasound and ECG Holter monitoring. Polymorphism of the RAS genes (renin gene (REN) G83A, angiotensinogen gene (AGT) M235T, angiotensin-converting enzyme gene (ACE) I/D, angiotensin II receptor type 1 gene (AGTR1) A1166C). Results : in patients with HCMP was established a higher frequency of TT-genotype and T-alleles of angiotensinogen gene than in comparison group. In homozygous patients with T-allele of angiotensinogen gene ventricular arrhythmia was found reliably more often than in patients with MT- and MM-genotypes, which suggested that M235T polymorphism of angiotensinogen gene influenced on intensity of ventricular arrhythmias in children with HCMP. Conclusions : in children with HCMP and cardiac arrhythmias analysis of M235T polymorphism of angiotensinogen gene can be used as an additional criterion for revealing of patients with high risk of arrhythmic complications and for development of preventative measures.