Histoenzymology of the contractile myocardium in experimental pulmonary stenosis.

Metabolism of contractile cardiomyocyte in experimental pulmonary stenosis complicated or not complicated by heart failure was studied by histochemical methods. In pulmonary stenosis not complicated by heart failure, intensification of glycolysis, more intense oxidation of free fatty acids and their metabolites, and acceleration of the citric acid cycle were found in the contractile cardiomyocytes. In pulmonary stenosis complicated by heart failure, glycogen content in the myocardium was sharply decreased. The histochemical enzyme profile of contractile cardiomyocytes is similar in pulmonary stenosis with and without heart failure. Comparative analysis of changes occurring in acute increase in afterload of the left or right ventricle suggested that in the latter case, metabolic abnormalities in the contractile cardiomyocytes are relatively unimportant in the pathogenesis of heart failure.