[Structural variability of cardiomyocytes of various parts of the heart in its hyperfunction].

By means of morphometrical and histological methods hearts of 84 white rats have been studied in 3 months after right-sided pulmonectomy. Cardiac hyperfunction resulted is accompanied with an increased mass of its parts, where hypertrophy of the right ventricle and atrium predominate. Hypertrophy of myocardial parts takes place mainly at the expense of increasing length and width of cardiomyocytes; this causes disorganization and disordering of morphological systems and an essential decrease of compensatory possibilities of the hyperfunctioning heart parts.