[Morpho-functional characteristics of the myocardium in extreme coronary insufficiency].

Morphogenesis of destructive and adaptational changes of the myocardial contractility were studied experimentally on dogs with limited bloodflow in the left coronary artery by 90% for 30 min. The light coronary methods and electron microscopy were used. The main ultrastructural variants of contractility disorders and cardiomyocyte damage are described, qualitative nonidentity of mechanisms in the ischaemic focus and in conditionally intact segments are recorded. It shows that irreversible structural shifts in the ischaemic zone of the myocardium develop along with the decrease of contractility, while in the intact areas this is preceded by intensive work of cardiomyocytes. At the base of adaptational reaction at the tissue level lies the formation of microfoci of functional hyperactivity and a relative rest.