The principal forms of acute cardiomyocyte damage of metabolic and ischemic genesis are accompanied by changes in the contractile apparatus, which is reflected in double refraction of myofibrils. Thus, polarization microscopy is the most sensitive method allowing one to detect the early stages of cardiomyocyte damage. Individual types of cardiomyocyte lesions are identified on the basis of parallel histological studies and polarization and electron microscopy of prenecrotic alterations and myocardial infarction using experimental and autopsy material. They are: I, II, and III degree myofibrillar contracture, intracellular myocytolysis, primary lumpy degradation of myofibrils, and cytolysis. These types of damage form the morphological basis of acute myocardial pathology with a possible outcome of coagulative or colliquative necrosis.
Key Words: metabolic and ischemic myocardial damage; ventricular fibrillation; myocardial infarction; cardiomyocyte myofibrils; polarization and electron microscopyThe pathogenesis, diagnosis, and prognosis of various types of cardiomyocyte lesions have preoccupied researchers for a long time and stimulated an ongoing search for new methods of indentifying the pathological processes. Morphological analysis, which permits evaluation of the spectrum of alterations in structural and tissue interactions as well as their intensity and scope, is of great importance. The search for methods of identifying individual types of injury with specific characteristics and outcomes is an important aspect of morphological analysis [7,11,25,32].For a long time, dystrophy and necrobiosis were considered to be the major and clinically most important changes taking place in cardiomyocytes (CM). focal metabolic cardiac damage and myocardial infarction. Dystrophic alterations in CM, which often precede necrosis, make up a large group of lesions differing in their mechanisms of development and morphological manifestations. Polarization microscopy has made it possible to identify early stages of CM damage at the light microscopy level [20,33,[45][46][47]49].Basic research into the nature and dynamics of morphological changes in CM caused by various agents or conditions modeling acute human myocardial pathology has been performed for the first time by Russian scientists with the use of polarization microscopy [1,2,20,25,32,33]. Up to 1985, these studies were carried out under the supervision of Dr. Yu. G. Tsellarius. It was found that different changes in myofibril structure revealed by polarization microscopy provide a basis for the classification of acute CM lesions [34].Myofibrils respond to alterative stimuli by a complex of structural disorders that are not specific for any
