[Differences in the ultrastructural reorganization of the myocytes of the atria and ventricles in the stages of the correction of mitral heart defects].

Ultrastructure and stereomorphometry of the myocardium biopsies from 12 patients are studied at various periods of the correction of mitral vitium cordis under the conditions of total body hypothermia. It is shown that compensatory changes enhance the morphological differences between the left atrium cardiomyocytes in stenosis of the mitral aperture and those in left ventricle in deficiency of mitral valve. By the end of operation the ventricle cardiomyocytes are damaged at a higher degree showing the pronounced myofibrillary contracture. The atrium myocytes having a labile protein-synthetic apparatus are more resistant to the damaging effect of operation. Morphofunctional specialization of different heart compartments should be taken into consideration in diagnostic practice.