[Changes in the enzymatic activity in the myocardium of patients with idiopathic and secondary dilated cardiomyopathy].

Myocardial biopsies from patients with dilated cardiomyopathy (DCMP) were studied histochemically. The patients were divided into the following groups: 1) idiopathic DCMP; 2) patients with postmyocarditis DCMP (an increase of lymphocytic-macrophagal elements in the myocardium); 3) secondary DCMP against alcoholic myocardial damage. Idiopathic and secondary DCMP are characterized by the following enzymatic changes: a decrease in the activity of the majority of oxidation-reduction mitochondrial enzymes, normal or increased activity of malate dehydrogenase, increased activity of lysosomal and microsomal enzymes. An increased activity of succinate dehydrogenase was observed only in patients who had previous myocarditis. Alterations in idiopathic and alcoholic DCMP were practically identical.