Aim: To study the state of cardiac tissue homeostasis in the process of ontogenesis in prematurity in the light of modern fundamental knowledge on the biology of cardiac stem cells, the structure of cardiomyocytes, paracrine regulation mechanisms and other pathogenetic mechanisms affecting the growth, development and remodeling of the cardiovascular system in childhood and in follow-up.Literature search strategy. A search for studies and analytical literature reviews was conducted in databases Cochrane library, MEDLINE, Google Academy, PubMed and other databases mainly from the beginning of 2018 to December 2023. Publications/ studies reflecting various aspects of the physiology of the infant heart in premature infants (clinical and experimental aspects) were independently selected for inclusion. Preference was given to randomized controlled trials.Results. Based on modern concepts of pre- and post-implantation (postnatal) development and growth of the infant heart, the analysis of the processes of postnatal growth and development of the heart of children born healthy full-term and premature with spontaneous natural conception is given. The analysis of the main pathogenetic mechanisms influencing the processes of growth and development of the child’s heart in the intrauterine and postnatal period is carried out.Conclusion. Experimental and clinical data reasonably require a conscious revision of the fundamental theoretical postulates about the regenerative capabilities of the myocardium in various periods of childhood, including the clinical group of premature babies, and practical guidelines for pregnancy management with the threat of abortion and infertility (preimplantation measures using assisted reproductive technologies), combined/intensive (including, respiratory) therapy in the neonatal period, longterm outpatient follow-up of children and adults born prematurely with low, very low and extremely low body weight in order to prevent, screen and treat potential effects on the health of the cardiovascular system throughout life. The information provided is very useful for a wide range of readers – biologists, embryologists, reproductive doctors, obstetricians, gynecologists, neonatologists, pediatricians, internists, cardiologists, surgeons.

Highlights. The hypothesis of the evolution of LV twisting types is proposed, which is based on the gradual transformation of LV twisting types as a prerequisite for postnatal growth and development of heart chambers in healthy children and adolescents. In the future, the transition of one type of LV twist to another will enable us to diagnose the predominance of growth and maturation of the fibrous skeleton, apex, vortex cordis, trabecular apparatus, as well as creating projections of the individual development and growth of the heart in childhood and adolescence. Abstract. Modern data on the nature of the mechanics of the left ventricle (LV) in postnatal ontogenesis in healthy children and adolescents born full-term are fundamental, since they allow not only to determine ontogenetically conditioned variants of individual development of contractile-rotational mechanisms of LV in the process of growth and development, but also, if necessary, make it possible to identify subclinical dysfunction in the early stages, monitor the effectiveness of complex therapeutic and rehabilitation measures. The article analyzes newly established fact of the absence of static character of the selected various forms of LV twisting into a systole and the ability of their transformation in the process of growth and development. This fact forms the basis of the author's original hypothesis of “the evolution of LV twisting models”, which provides the optimal ontogenetic growth of the child and adolescent heart in the postnatal period. The hypothesis of “evolution of left ventricular twisting types” is based on modern knowledge about multifaceted processes at the tissue level, the mechanics of LV in the individual rate of development and growth of the heart in childhood and adolescence.

Purpose. The study assessed left ventricle longitudinal strain of the endocardial, middle, and epicardial layers in children from one to five years old, born with low, very low, and extremely low body weight.Material and methods. The study was performed in 204 children aged from one to five years; of these, 53 children were prematurely born late in pregnancy, 103 children were born very preterm, and 48 children were born healthy and full-term. The left ventricle longitudinal strain of the endocardial, middle, and epicardial layers was assessed off-line using the Speckle Tracking Imaging-2D Strain technology.Results. Disturbance of the transmural gradient strain of left ventricle wall were detected in 11.32% of prematurely born late in pregnancy children and in 16.5% of very preterm children. A decrease of left ventricle segments strain was registered in 33.96% of children prematurely born late in pregnancy and in 18.44% very preterm children. In children of the same age, born healthy and full-term, transmural wall gradient disturbances and decrease of strain in left ventricle segments were not observed. In children prematurely born late in pregnancy, the disturbance of the transmural strain gradient of left ventricle and the decrease of strain in left ventricle segments are not associated with left ventricle remodeling.Conclusion. The development of the cardiovascular system in children of early and preschool age, born prematurely with low, very low, and extremely low body weight, is characterized by disturbances in the transmural strain gradient of left ventricle wall, due to the processes of postnatal growth and development of the child’s heart, which requires monitoring on an outpatient basis in polyclinic in childhood — by a pediatric cardiologist and a pediatrician, and in adulthood — by a cardiologist and therapist.

Высокие риски неблагоприятных событий со стороны сердечно-сосудистой системы в группе взрослых, рожденных недоношенными, требуют усиленного изучения вопросов физиологии и патофизиологии детского сердца при наличии информации о преждевременных родах в анамнезе, являющихся по современным представлениям хроническим состоянием. Истоки заболеваний сердца и сосудов во взрослом возрасте берут начало в патологии антенатального и раннего неонатального периодов развития и определяют в известной степени качество жизни взрослых пациентов в отдаленные временные промежутки. Использование современных неинвазивных ультразвуковых технологий исследования сердечно-сосудистой системы у детей, рожденных недоношенными с низкой, очень низкой и экстремально низкой массой тела, позволило получить новые данные фундаментального характера, а также существенно расширить традиционные представления о природе торсионных механизмов и вкладе потокогенной составляющей в процессы постнатального онтогенеза. Развитие различных моделей контрактильно-ротационных процессов и формирование нескольких вариантов вихревых диастолических потоков левого желудочка у детей в возрасте от одного года до пяти лет, рожденных недоношенными, является неотъемлемой частью процесса постнатального онтогенеза детского сердца при условии наличия фактора преждевременных родов в анамнезе. High risks of adverse cardiovascular events in the group of adults born prematurely require an intensified study of the physiology and pathophysiology of the child heart given the history of preterm birth, which is considered as chronic condition under modern concepts. The origins of heart and vascular disease in adulthood originate in the pathology of antenatal and early neonatal periods, determining to a certain extent the quality of life of adult patients in remote time intervals. The use of modern non-invasive ultrasound technologies for studying the cardiovascular system in children born prematurely with low, very low and extremely low body weight allowed to obtain new fundamental data as well as to expand significantly conventional conceptions of the nature of torsion mechanisms and the contribution of the flow-generating component in postnatal ontogenesis. The development of various models of contractile-rotational processes and the formation of several variants of left ventricular vortex diastolic flows in preterm-born children aged one to five years is an integral part of the process of postnatal ontogenesis of the child heart given a history of preterm birth.

Aim: To study contractility of the left ventricle (LV) in prematurely born children of early and preschool age who received treatment in intensive care units, neonatal intensive care units and pathology of newborns in the neonatal period.Material and Methods. The study included 155 children, of which 108 children aged from one to five years old, born with very low body weight and extremely low body weight; and 47 children of the same age, born full-term and healthy. Study design: pilot, cross-sectional, retrospective, case-control study. EchoCG was performed using the Vivid E9 ultrasound system (GE, Healthcare) with M5S matrix probe (1.5–4.6 MHz). The LV global circumferential (GCSMV, GCSPM, GCSApex), and longitudinal strain, as well as the global strain of the endocardial, middle and epicardial layers of the LV were assessed. in the systole “clockwise”) was found in 33.33% of children with a history of bronchopulmonary dysplasia, and in 28.13% of children who received mechanical ventilation during the neonatal period. In 25 (69.44%) of 36 children with signs of anemia in the neonatal period, there was a decrease in deformation along the circumference of the LV epicardial layer. In 13 (86.67%) of 15 clinical observations with signs of transient hypothyroidism in the anamnesis, a decrease in deformation along the circumference of the epicardial layer was revealed.Conclusion. Factors “body weight at birth”, “fetal growth retardation”, “anemia, use of mechanical ventilation in the neonatal period”, “transient hypothyroidism”, “development of bronchopulmonary dysplasia” in children of early and preschool age born prematurely with very low and extremely low body weight, adversely affect the formation of LV contractility and rotational mechanics in the postnatal period, exacerbating the disorders caused by the immaturity of the child’s heart tissue and the implementation of other pathogenetic mechanisms in prematurity, which requires medical supervision of this clinical group in polyclinic conditions.

Прогрессивный взгляд на биологию лактации и физиологию грудного вскармливания позволяет рассматривать грудное молоко кормящей женщины в качестве «живой системы и иммунного органа». Обнаружение в составе грудного молока различных пулов клеток, включая стволовые клетки грудного молока, а также экзосом, содержащих микроРНК, делает возможным понимание и объяснение на новом уровне особенностей развития сердечно-сосудистой системы у взрослых и детей, рожденных недоношенными и получавших в течение первого года жизни различные варианты вскармливания. Отсутствие при вскармливании детей первого года жизни грудного молока приводит к более выраженным изменениям морфологии (ремоделированию) и функциональных характеристик сердца, преобладанию особых («реверсивных») форм вращения левого желудочка, что свидетельствует о специфичных закономерностях формирования механики, роста и развития детского сердца у рожденных преждевременно в постнатальный период. Междисциплинарный подход, изучение грудного молока с точки зрения сложной биосистемы, а не только как источника питательных веществ помогут установить влияние характера вскармливания детей до года на процессы постнатального роста и развития детского сердца при условии наличия фактора недоношенности в анамнезе. Дальнейшее исследование влияния на организм недоношенного ребенка компонентов грудного молока призвано революционно изменить традиционные представления о биологии лактации и физиологии грудного вскармливания, а также существенно скорректировать теоретические фундаментальные постулаты по физиологии/патофизиологии постнатального роста, развития и функции сердечно-сосудистой системы. A progressive outlook on the biology of lactation and the physiology of breastfeeding allows the breast milk of a nursing woman to be considered as a "living system and immune organ." Discovering of various cell pools in breast milk, including breast milk stem cells and exosomes containing microRNAs, makes it possible to understand and explain at one new level features of cardiovascular system development in adults and prematurely born children received various feeding options during the first year of life. The absence of breast milk during feeding of children in the first year of life leads to more pronounced changes in morphology (remodeling) and functional characteristics of the heart and the prevalence of special ("reversible") forms of left ventricular rotation, indicating specific patterns in formation of mechanics, growth and development of heart in children born prematurely in postnatal period. An interdisciplinary approach and the study of breast milk in terms of a complex biosystem and not only as a source of nutrients would help to establish the impact of the nature of feeding children under one year of age on processes of postnatal growth and development of child heart, under condition of prematurity factor in the history. Further investigation of breast milk components’ impact on premature infant’s organism is intended to breakthrough conventional conceptions of lactation biology and breastfeeding physiology as well as to adjust in substantial way theoretical fundamental postulates on the physiology/pathophysiology of postnatal growth, development and function of the cardiovascular system.

An increase in the birth rate of premature and low birth weight children at the current level of medical development requires the development of fundamental ideas about the physiology of the cardiovascular system in a history of preterm birth from the point of view of pre- and postnatal ontogenesis. For practicing neonatologists, pediatricians, therapists, cardiologists, reproductologists, etc., it is necessary to improve the traditional ideas about the mechanisms of damage to the cardiovascular system in this category of patients. Because it is established that this clinical subgroup is characterized by increased risks of early onset of pathology of the heart and blood vessels, as well as a high mortality rate in adulthood. Pathological changes of the cardiovascular system in conditions of prematurity can occur at various levels of integration of the body (molecular, subcellular, cellular, organ, functional systems, organismal). The use of modern noninvasive technology of “spot tracing” makes it possible to study the features of segmental deformation and the variety of forms of left ventricle (LV) torsion mechanics during postnatal growth and development in prematurely born children. Optimization of research and diagnostic processes in the field of mechanics of the infant heart in the prenatal and postnatal periods from the point of view of progressive data on anatomy, histology, and clinical biochemistry allows us to study the nature of various contractile–rotational models, as well as reasonably assume the contribution of the fibrous skeleton of the infant heart to the formation of “childhood types” of left ventricular twisting. The search and development of informative criteria for the early diagnosis of latent subclinical heart dysfunction in childhood, taking into account the possibilities of non-invasive ultrasound technology of spot tracing (analysis of types of rotational movement, determination of areas of reduced longitudinal deformation of the LV), based on the current provisions of evidence-based medicine, have become quite possible in modern conditions and are demonstrated by the authors in this review. The information offered to the readers will allow them to expand the understanding of the physiology and pathophysiology of the infant heart with a history of premature birth, bearing in mind the fact that prematurity is considered a chronic condition.

The active use of assisted reproductive technologies has allowed us to achieve very impressive results, which allows us to consider this method as one of the effective approaches to infertility treatment. More than eight million children have been born worldwide with the help of assisted reproduction to date. At the same time, assisted reproductive technologies are an important risk factor, since long-term consequences for the morphology and function of the child’s heart can predispose to premature cardiovascular morbidity and mortality. These facts require a revision of traditional ideas about the long-term safety of their use, the formation of special registers. The creation of registers of the use of assisted reproductive technologies optimizes the process of long-term monitoring of children born with their use. The analysis of experimental and clinical studies presented in the review creates a theoretical basis for understanding the subtle mechanisms of the formation of postnatal health in children born prematurely and in the process of using inflammatory reproductive technologies. This review of the literature will allow doctors of various specialties (embryologists, reproductologists – obstetricians-gynecologists, neonatologists, pediatricians, therapists, cardiologists) and producers of culture media to significantly expand traditional ideas about the impact of assisted reproductive technologies on the health of the cardiovascular system in childhood, since even small changes in the conditions of cultivation and the composition of the culture medium for the embryo, the peculiarities of the course of pregnancy can have significant delayed effects on the health of children, born with the use of assisted reproductive technologies. Therefore, it is obvious the importance of monitoring children of this clinical group in order to further clarify possible long-term health consequences, a deeper understanding of the fundamental patterns of postnatal development and early diagnosis of subclinical disorders of the cardiovascular system.

This literature review analyzes current data on the main stages of child’s heart contractility development from prenatal to postnatal period. The presented information will expand the conventional ideas on the age-related cardiovascular physiology in children, supplementing with relevant knowledge about the patterns of left ventricular mechanics, and the mechanisms affecting child’s heart morphology. In addition, we consider the evolutionary feasibility of the simultaneous existence of various left ventricular mechanics models, which ensure the effective cardiac function in the postnatal period. This is very important for the work of neonatologists, pediatricians, pediatric cardiologists and therapists.

The review of literature is devoted to the analysis of prospects for using breast milk in neonatology, pediatrics, and pediatric cardiology to optimize the postnatal growth and development of children born prematurely.

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%.

The aim of the study is to assess the left ventricle (LV) untwist in healthy children and adolescents born fullterm.Materials and methods. The analysis was carried out in 108 healthy children aged 2 months to 18 years, born full-term. LV untwist is assessed using Speckle Tracking Imaging at the basal and apical level.Results. Four types of LV untwist were identified in children and adolescents. We did not find relation between LV untwist and age, nor with LV index spherical in systole and diastole, LV myocardial mass. The relationship between LV untwisting and LV rotation in systole at basal and apical segments was revealed.Conclusion. The described features of LV loosening are apparently associated with processes of postnatal growth and maturation of heart tissues in children and adolescents.