Pacing is currently the main method of treatment in children with life-threatening bradyarrhythmias. The high-grade atrioventricular block remains the main indication for permanent pacing in children. The factors that determine the specificity of device implantation in the pediatric population are as follows: anthropometric data of a child and their compliance with the size of a pacemaker and the electrodes, the need for long-term (lifelong) cardiac stimulation and multiple replacements of a pacemaker, high level of child’s activity, changes in the physical parameters of the body over time (the need for implantation of the leads “with reserve” and their replacement), and, in some cases, the presence of concomitant congenital heart defects, especially, with intracardiac shunts. One of the controversial issues in pediatric cardiac stimulation is choosing a method of implantation (epicardial or endocardial). According to recent reports, the epicardial lead implantation techniques are increasingly being used because the transvenous pacemakers are associated with more serious complications and due to the capability to choose hemodynamically optimal stimulation zone in epicardial technique to prevent pacemaker-induced dyssynchrony. This approach allows to ultimately postpone the implantation of the endocardial stimulation system, administration of which is associated with the problem of endovascular lead extraction in children, the problem, which has not been resolved not only in Russia but also worldwide. This review article discusses recent literature on the use of permanent pacing in children, including the advantages and disadvantages of using the endocardial and epicardial pacemaker systems as well as various methods of implantation and pacemaker modes most often used in pediatric practice.

The significant spread of obesity among adults and children represents a relevant problem for the modern health care system. Diagnosis and correction of the earliest signs of cardiometabolic disorders in children with obesity are necessary since their monitoring and modification allow to influence the development and prognosis of cardiovascular pathology in the future. This article highlights the current knowledge on the markers of cardiovascular risks such as dyslipidemia, the level of trimethylamine N-oxide, the state of epicardial adipose tissue, and the initial signs of myocardial remodeling.

This review summarizes the results from national and international studies regarding the quantitative and qualitative composition of intestinal microbiota in health and the dominance of certain bacteria in the intestinal microbiota of obese children. Moreover, we discuss the relationships between the development of obesity and the changes in the composition and metabolic activity of intestinal microbiota in children. These analyses are of scientific interest from the perspective of finding new targets and approaches to conservative management aimed at preventing and treating obesity through the restoration of intestinal microflora.

On March 11, 2020, the World Health Organization declared COVID-19 apandemic. Despite a large number of scientific publications concerning the clinical picture and trea tment methods, data on structural changes of internal organs in COVID-19 is still insufficient. This review presents and analyzes several clinical cases published by research groups in various countries. COVID-19 infection is caused by a SARS-CoV-2 virus that binds to the angiotensin-converting enzyme 2 ACE2 receptor. Interaction with this receptor is the initial stage of pathogenesis. The morphological picture is similar to pneumonia caused by SARS-CoV and MERS-CoV: at the initial stage, a picture of shock lungs develops, later it ends in fibrosis and organizing pneumonia. One of the most severe complications is acute respiratory distress syndrome, which is observed in some clinical cases reviewed. In this article, we collected cases of clinical and morphological studies of patients with COVID-19, published in international peer-reviewed medical literature to date.

Aim. To study the features of recovery period of hypoxic lesion to the central nervous system (CNS) in children of the first year of life in the presence of congenital heart disease (CHD).

Material and Methods. The study involved 80 children born full-term and premature with gestational status of 35–37 weeks with hypoxic damage to the CNS. The main observation group comprised 50 children with CHD (interventricular and atrial septal defects, open ductus arteriosus). All children underwent a comprehensive health assessment, standard echocardiography, and neurosonography at ages of five to seven days and one, three, and six months. Biochemical analysis included assessment of serum neurospecific enolase (NSE), succinate dehydrogenase (SDG), and α-glycerophosphate dehydrogenase (α-GPDH). The control group included 20 full-term newborns without CHD and CNS lesions.

Results. The main manifestations in newborns with CHD and hypoxic damage to the CNS were the suppression syndrome, agitation, and hypertension-hydrocephalic syndrome. At the age of six months, a delay in motor development indicators persisted in 35% of children in the main group. The high NSE level in newborns with concomitant septal heart defects was associated with a decrease in the quantitative indicators of neuropsychic development (g = –0.6, p < 0.05). The children with CHD and hypoxic damage to the CNS in the first year of life were significantly more often (p < 0.05) deficient in weight and height. A decrease in the resistance level in the first year of life was observed in 40% of children from the main group, which significantly differed compared with group of children without CHD (p < 0.001). The newborns with hypoxic CNS and CHD lesions had a decrease in the activity of α-GPDH and SDG at the age of five to seven days; the low activity of SDG persisted at the ages of one and six months; the enzyme activity in children of the comparison group was normal (p < 0.05).

Conclusion. Children with CHD had the features of clinical course of perinatal damage to the CNS in the acute and recovery periods, a slowdown in the rate of physical and neuropsychic development, a decrease in the resistance level, and impaired functional state of the body. The decreases in the activities of SDG and α-GPDH in children with hypoxic lesions to the CNS in the presence of CHD implied the disturbances in cellular bioenergetics and resulted in inadequate response to external factors.

Studying the long-term results of surgical correction of CHD in children is an urgent problem in the modern world, since there are currently no uniform criteria for assessing the long-term results of this type of intervention.

Objective. To study the social and psychological characteristics of children with congenital heart disease after surgery to predict possible risks of adaptation disorders in the long term period.

Material and Methods. Social and emotional functioning of 116 children with congenital heart disease after surgical treatment was assessed using the Pediatric Quality of Life Questionnaire PEDsQL4.0. Children were divided into two groups: children from families with (group 1) and without unfavorable social and economic factors (group 2).

Results and Discussion. Lower indicators of health were observed in group of children with familial history of various unfavorable social and economic factors as well as in children with more complicated defects and comorbidities during threeyear follow-up.

Conclusion. Integrated dynamic differentiated observation is essential during the follow-up of patients with congenital heart defects. While creating a rehabilitation program, it is necessary to take into account all components of health, including the psychosocial functioning of the child, and to implement a personalized approach to rehabilitation on this basis.

The aim of the study was to evaluate the types of left ventricular (LV) rotation depending on the nature of feeding during the first year of life in oneto five-year-old children born with very low and extremely low body weight.

Material and Methods. The study included 88 children aged one to five years, born deeply premature with very low and extremely low body weight. The comparison group consisted of 46 healthy children of the same age, born full-term. TheLV mechanics was studied based on the assessment ofLV rotation at the levels of the mitral valve, papillary muscles, and apex andLV twist using two-dimensional echocardiography and two-dimensional speckle-tracking strain imaging.

Results. Differences between the types ofLV twist and the nature of feeding during the first year of life in oneto five-year-old children born with very low and extremely low body weight were identified. In children with natural feeding, the first (“adult”) type ofLV twist was registered in 75% of cases; the fourth type ofLV twist was detected in 12.5% of cases. In children with bottle-feeding during the first year of life, the “adult” type ofLV twist was registered in 34.38% of cases; fourth type ofLV twist was detected in 40.63% of children born deeply premature. In children with mixed feeding during the first year of life, the ratio ofLV twist types was as follows: 40.63% of patients had the first “adult” type; “child” types were present in 18.75% and 18.75% of children, respectively; fourth type of twist was detected in 21.88%.

This work reviews the reasons why the characteristics of left ventricular (LV) contractility, in particular, and 2D speckle echocardiography-based peak rates of global longitudinal strain (GLS), are not widely used in clinical practice. Authors present the analysis of new indicators proposed for the assessment ofLVcontractile function based on longitudinal strain taking into account the involvement of individual segments. The authors show that the assessment of myocardial work indicators characterizing the relationships between contractile and pump functions is a promising approach for the study ofLVcontractile function. The analysis of postsystolic strain index (PSI) is presented to illustrate its clinical implementation in the studies of viable myocardium in ischemic conditions and evaluating the effectiveness of cardiac resynchronization therapy (CRT).

Purpose of research. To study the effect of hydrogen sulfide and carbon monoxide donors on collagen-induced platelet aggregation in healthy donors and patients with coronary artery disease.Introduction. There is evidence that the hydrogen sulfide (H₂S) and carbon monoxide (CO) gas transmitters play an essential role in regulating the functional activity of various organs and systems of the human body. According to previous reports, CO and H S are considered inhibitors of platelet aggregation.

Material and Methods. A total of 37 participants were examined during the study. The control group included 13 healthy donors; group of patients with coronary artery disease comprised 24 people. All examined patients received regular combination baseline therapy in accordance with modern recommendations for the treatment of coronary artery disease. Platelet aggregation activity was studied by a turbidimetric method using a two-channel laser analyzer (220 LA Biola, Russia). The degree and rate of platelet aggregation were determined in platelet-rich plasma based on the curves of light transmission and the average size of aggregates as markers of the functional activity of platelets. Collagen at a final concentration of 2 mg/mL was used to induce platelet aggregation. Sodium hydrosulfide (NaHS) was used as a hydrogen sulfide donor. Carbon monoxide-releasing molecule-II (CORM-II) was used as a carbon monoxide donor. Experimental data are presented as Me (Q₁ –Q₃). Wilcoxon T-test was used to test the homogeneity of paired or dependent samples. Values were considered tatistically significant when p was < 0.05.

Results. A hydrogen sulfide donor causes a decrease in collagen-induced platelet aggregation along the light transmission curve in both healthy donors and patients with CHD. Collagen-induced platelet aggregation along the light transmission curve is reduced by the action of the carbon monoxide donor in healthy donors, the effect is more pronounced than in patients with CHD.

The aim of the present study was to assess the relationships between subpopulations of FoxP3+ T-lymphocytes (Treg) and metabolic parameters of peripheral blood in patients with coronary heart disease (CHD), depending on the presence of diabetes mellitus (DM) type 2.

Material and Methods. The study material was mononuclear peripheral blood leukocytes. FoxP3+ Treg numbers and nuclear translocation of FoxP3 were evaluated by imaging flow cytometry.

Results and Discussion. An inverse relationships was revealed (r = –0.900; p = 0.037) between the level of LDL cholesterol (low density lipoprotein cholesterol) and the level of FoxP3 translocation in CD4+CD25hiFoxP3+ and CD4+CD25loFoxP3+ lymphocytes in patients with diabetes. In patients without diabetes, a direct relationship was found between the level of FoxP3 nuclear translocation in CD4+CD25loFoxP3+ lymphocytes with high non-HDL cholesterol (total cholesterol without HDL cholesterol) (r = 0.900; p = 0.037). A direct correlation was also observed between the glucose concentration and the number of CD4+CD25loFoxP3 + lymphocytes (r = 0.900; p = 0.037).

Conclusion. The level of transcription factor FoxP3 nuclear translocation correlated with the content of LDL cholesterol in patients with coronary artery disease in the presence of type 2 diabetes mellitus. The orientation of bonds was different for the conventional and regulatory subpopulations of T-lymphocytes. The metabolic parameters correlated with the level of transcription factor FoxP3 translocation exclusively in conventional T cells in patients with coronary artery disease in the absence of type 2 diabetes mellitus.

Introduction. Patients with obstructive sleep apnea syndrome (OSA) may have features of acute ST-segment elevation myocardial infarction (STEMI). We assumed that the previous OSA due to acute and chronic hypoxia has a “protective” effect on myocardial damage in STEMI. To assess the damage to the myocardium, we selected the index of local contractility disorders (ILCD), and used the oxygen desaturation index (ODI) to assess OSA’s severity.

Aim. To study the relationship between myocardial damage and the severity of OSA in STEMI after percutaneous coronary intervention (PCI).

Material and Methods. We examined 130 patients with first-time STEMI after PCI on the infarct-associated coronary artery. Examination and treatment of patients were performed based on current procedures and standards of medical care and clinical recommendations. All patients were monitored for pulse oximetry during nighttime sleep within one week after hospitalization. The patients were divided into two groups: group A (n=59, ODI 0-5/hour, STEMI without OSA) and group B (n=71, ODI >5/ hour, STEMI with OSA).

Results. Regression analysis showed that the elements of myocardium’s structural remodeling, the severity of OSA, and some biochemical indicators are included in the same indicator system and are associated with ILCD. The “left ventricular ejection fraction” (“LVEF”) indicator, estimated using the J.S. Simpson method, had the largest contribution to the ILCD in both groups of patients, while the “ID” indicator backfired on ILCD only in the group of STEMI with OAS. Thus, OSA contributed to less damage to the left ventricular myocardium in STEMI.

Objective: To investigate the incidence of left atrial appendage (LAA) thrombosis and to assess the oral anticoagulation (OAC) in patients with non-valvular atrial fibrillation (AF) before catheter ablation.

Material and Methods. We studied 638 patients with AF who underwent transesophageal echocardiography before AF ablation from 2014 to 2017. The analysis included the baseline characteristics of patients.

Results. There was no statistical difference in the risk of thromboembolic complications (TEC) in patients with and without OAC. All patients were divided into four groups: 167 patients (26.2%) received warfarin (group 1); 128 patients (20.1%) received dabigatran (group 2); 145 patients (22.7%) received rivaroxaban or apixaban (group 3); and 198 patients (31%) were not administered with OAC (group 4). Among patients without OAC, only 26 individuals (13.1%) had a low TEC risk, whereas 172 patients had a moderate or high TEC risk. Half of group 4 received antiplatelet drugs, but a third of them had a high TEC risk and were recommended to take OAC. Patients in the pre-ablation period received different types of OAC with the same frequency. LAA thrombosis was detected in 44 patients (6.9%). Significant differences in the incidence of LAA thrombosis in patients receiving different OAC were not detected. LAA thrombosis was detected in one patient receiving dabigatran with a low risk of TEC. There was also a trend for more frequent therapeutic levels of INR in patients taking warfarin with LAA thrombosis and there were no patients with INR > 3.0. About half of patients without thrombosis were treated with subtherapeutic warfarin therapy, and only a third of them had the therapeutic range of INR.

Conclusion. Not all patients with non-valvular AF take OAC at the pre-ablation period. All types of OAC are prescribed with the same frequency. Differences in the incidence of LAA thrombosis, depending on the received OAC, were not detected. There was no association between the detection of thrombosis and the therapeutic range of INR in group 1. There were no significant differences in the incidence rates of LAA thrombosis between warfarin, dabigatran, rivaroxaban, or apixaban.

Aim: To evaluate the electrical activity of the myocardium and the radiofrequency (RF) application zone resulting from radiofrequency ablation (RFA) performed at an early age.

Material and Methods. A prospective follow-up study included three patients who underwent intracardiac electrophysiological study (EPS) and effective RFA of the tachycardia for the first time at an early age. A reintervention was required in one case 12 years after the procedure and in two cases six years after it due to recurrent and new-onset arrhythmias. During the reintervention, electroanatomical mapping was performed to assess the potential damaging effect of radiofrequency exposure in the area of the first ablation.

Results. The intracardiac EPS and amplitude bipolar CARTO-reconstruction of primary ablation area were performed during repeated RFA procedure. The study showed that neither zones with a decrease in the amplitude of electrical signal from the myocardium nor silent electrical zones were present ruling out the cicatricial-sclerotic changes in the myocardium in children in the long-term period after RF exposure.

Conclusion. The study showed that no increase in the coagulation necrosis zone in the area of primary ablation occurred during the growth of child when the sparing energy and temperature parameters of RFA and the limited number of RF applications were used. Further research in this area is required.

Duplex ultrasound scanning (DUS) and magnetic resonance imaging are sometimes insufficient to meet our clinical needs due to specifics of given pathology and intrinsic technical limitations of these methods. This study aims to assess the need for multispiral computed tomography–venography (CT-venography) and to evaluate its diagnostic capabilities for various disorders in primary ambulatory patients in phlebology practice.

Material and Methods. From January, 2017 to December,2019, a total of 10,112 patients sought initial consultation of a phlebologist. Upon examination, the physician assigned patients to one of the proposed categories using dedicated software. Analysis of these categories demonstrated the following pattern of morbidity: 2,167 patients (21.4%) had chronic venous disorders of class С0S-1 (CEAP classification); 4,460 patients (44.1%) had varicose veins of class C2-3 (CEAP classification); 351 patients (3.5%) had varicose veins of class C4-6; 570 patients (5.6%) had other diseases including post-thrombotic syndrome, acute thrombosis, thrombophlebitis, and venous malformations; and 2,564 patients (25.4%) were suffering from non-venous disorders. DUS was performed in all cases.

Results. The study demonstrated that 260 patients required CT-venography constituting 2.6% of the total number of patients who came to the clinic in the indicated period. The direct venography with contrast medium injection through the peripheral veins was used in 156 cases (60%). Patients did not have any significant complications, such as acute kidney injury or worsening of chronic renal failure, severe allergic reactions to the contrast agent, or problems with the puncture site of peripheral veins.

Conclusions: 1) CT-venography allowed to achieve the accurate three-dimensional imaging of the venous system, providing, in some cases, the necessary information for finding solutions on optimal management. 2) The need for CT-venography may occur in 2.6% of patients in ambulatory phlebology practice. 3) CT-venography is useful for diagnosing angiodysplasias, postthrombotic and non-thrombotic lesions, complicated varicose veins, especially in recurrence, and in some cases of acute deep vein thrombosis. 4) DUS is mandatory for hemodynamic assessment in all patients before CT-venography.

Aim: To perform a territorial comparison of the incidence rates of certain cardiovascular diseases (CVD) in the pediatric population of the city ofVoronezh.

Material and Methods. The morbidity rates in the pediatric population over certain inner-city zones were assessed using a differentiated approach. This tactic was chosen taking into account historical background as a high percentage of the population (75.8% of the total population in the city district of Voronezh) was registered at particular clinics based on a territorial logic. Of these, 11 pediatric clinics in Voronezh provided care for over 160,000 children under the age of 14 years (about 79% of children residing in the city district of Voronezh) on a territorial basis. The ranking of indicators was performed using a specially designed software developed at the Voronezh State Medical University named after N.N. Burdenko. The territories at risk were identified based on the results of this analysis by the level and dynamics of morbidity in the pediatric population. Results. Cardiovascular diseases were below the top five leading disease classes and were ranked 8–9 in children in the context of overall morbidity structure in the city ofVoronezh. The study showed that the incidence of cardiovascular diseases increased in the adult population of Voronezh relative to the value for the same period analyzed last year: the growth rate in the number of medical care encounters was 14.65% with 14.05% of diagnoses established for the first time in life. The average long-term level of cardiovascular mortality in theVoronezh city district was 24.79 ± 1.40 cases per 1,000 children under 14 years of age.

Conclusion. The differences, found in the morbidity rates from the individual intra-city territories provided with pediatric polyclinics, can be explained by the various factors such as the age structure of the population residing in a particular region and human resources of a medical organization including the availability of a pediatric cardiologist. Knowledge of information regarding pediatric disease incidence in certain inner-city territories allowed us to rationally optimize the resources of the urban health system to improve the availability and quality of medical care to the population, particularly the young segments, suffering from cardiovascular diseases at the pre-hospital stage.

Introduction. The digitalization of medicine is one of the priority areas in country’s development. The transition of healthcare to digital medicine objectively requires special knowledge from medical students and a willingness to use digital medicine capabilities.

Aim. To study the relationships between student awareness in digital medicine and the level of education they receive; to evaluate the level of engagement and readiness to use telemedicine technologies depending on the educational level.

Material and Methods. The study was conducted by an in-person questionnaire survey among the students ofSiberianStateMedicalUniversity and Tomsk Medical andPharmaceuticalCollege. Based on the survey’s results, the primary database was created using the EpiData 3.1 program. Statistical analysis of data was carried out using the SPSS 13 package. To compare the frequencies, the Pearson χ2 criteria and the Fisher exact test, both two-sided, were used.

Results and discussion. The survey showed that only a part of the respondents was aware of digital medicine issues. The respondent students most often used e-health resources for search purposes. The analysis of statistical data revealed a correlation between awareness, attitude to digital medicine, and education level. The university students were more aware and open-minded to the potential use of digital medicine resources than the college students.

Conclusion. Young professionals were insufficiently informed in the field of digital medicine. Despite the positive attitude towards digital medicine, medical students were not active enough in using digital medicine capabilities. Most of the respondents believed that for the time being, the capabilities of digital medicine were limited. Many of the respondents raised concerns about healthcare data security.

Introduction. Recent evidence suggests that the quality of nutrition in the population is related to socioeconomic status. Besides, the mortality rate from alimentary-dependent diseases is high in the socioeconomically vulnerable groups of the population. Identifying the characteristics of diet depending on the socio-economic status of the population will help to establish effective ways for disease prevention and potentially reduce mortality rates.

Material and Methods. A total of 1,600 people aged 35–70 were surveyed to determine the education level, income, and family composition. The nature of nutrition was assessed using the Food Frequency Questionnaire, adapted for the Russianspeaking population. Statistical data analysis was performed using Statistica 6.0 software.

Results. Women preferred more fruits (score 32.0 [16.0-1744], QR = 10.0, p = 0.000), vegetables (74.0 [34.0–190.0] points, QR = 23.0, p = 0.000), and cereals (16.0 [7.0–32.0] points, QR = 6.0, p = 0.000) compared with men. The consumption of above-mentioned food groups increased with age. Urban residents more often preferred fruits (59.0 [24.0–135.0] points, QR = 20, p = 0.028) and soft drinks (24.0 [10.0–41.0] points, QR = 6, p = 0.005) compared with rural residents. People with higher education more often consumed the following food groups: cereals/porridge (16.0 [7.0–30.0] points, QR = 6, p = 0.000), nuts (2.0 [1.0–7.0] points, QR = 2, p = 0.000), and alcoholic and non-alcoholic beverages (29.0 [13.0–50.0] points, QR = 6, p = 0.000). High-income respondents more often preferred fruits (60.0 [24.0–124.0] points, QR = 19, p = 0.001), vegetables (92.0 [42.0–171.0] points, QR = 28, p = 0.047), animal products (47.0 [23.0–112.0] points, QR = 13, p = 0.005), and alcoholic and non-alcoholic beverages (29.0 [13.0–50.0] points, QR = 6.5, p = 0.000). Surveyed persons living with a family more often consumed fruits (58.0 [24.0–1782.0] points, QR = 19, p = 0.038), vegetables (92.0 [40.0–232.0] points, QR = 29, p = 0.001), animal products (47.0 [21.0–112.0] points, QR = 12, p = 0.000), potatoes and cereals (40.0 [16.0–69.0] points, QR = 9, p = 0.000), and non-alcoholic and alcoholic beverages (28.0 [10.0–50.0] points, QR = 6, p = 0.000).

Conclusion. The urban population with high income, high education level, and living with family as well as women and representatives of older age group more often consumed fruits, vegetables, and cereals in their diet compared with the rural population had low income, low education level, or lack of family.