Morphogenesis of injuries in adult nondescript dogs particular features of morphofunctional heterogeneity of contractile myocardium under a 30-min, 50-to-70 and 90-to-95 percent restriction of bloodflow in the circumflex branch of the left coronary artery were studied using histological, histochemical techniques and those of electronic microscopy. Investigating at the subcellular, cellular and tissue levels was important aspect of myocardial rearrangements. It has been ascertained that changes in the ischemic zone and in those regions agreed to be intact in the first run observation differed only quantitatively acquiring qualitative features in other observations, which fact is related to specificities of the cardiomyocite damaging mechanisms depending on the intensity of the ischemic impact. Important factors that determine patterness of changes in the paraischemic areas of the myocardium are microcirculatory disorders as well as destruction of nerve terminals that has been shown locally change the concentration of biologically active substances.