AGE FEATURES OF MORPHOFUNCTIONAL CHANGES IN NORMAL CARDIAC MUSCLE AND UNDER THE INFLUENCE OF DAMAGING FACTORS (LITERATURE REVIEW)

This article analyzes the recent literature on the age features of the structure and function of the intact heart muscle, as well as on the issue of heart remodeling in experimental animals of different ages under the influence of damaging factors. The myocardium undergoes morphological changes, with age, that occur as the restructuring of parenchymal and stromal components of the heart muscle. We point out the increase in mass of the heart and enlargement of its chambers with preferred hypertrophy and dilation of the left ventricular cavity during the aging process. The number of cardiomyocytes decreases throughout life. Quantitative changes of the cardiac cells are compensated by their hypertrophy. Reduction of the total volume of cardiomyocytes is accompanied by an increase of volume of connective tissue. The characteristic feature of aging is the accumulation of myocardial collagen in the interstitial space, exemia. The term "cardiac remodeling" includes the changes of both cellular and stromal components, volume of chambers of the heart cavities, which develop at pressure or volume overload, under the influence of various endogenous and exogenous factors. These lead to a structural reorganization of the heart muscle function. All chambers of the heart are remodeling. A significant number of clinical and experimental studies structural and functional reorganization of the heart under the influence of external and internal factors. However, the mechanisms of age-related changes in the myocardium at all levels of its organization structure are still questioned.