[Lactae dehydrogenase activity and its isoenzymatic spectrum in the myocardium in rheumatic heart defects].

The activity of lactate dehydrogenase (LDH) and its isoenzymatic spectrum were studied in biopsy specimen of the myocardium of 35 patients with mitral valvular disease who underwent operation. Starch gel electrophoresis was used. Four fractions of LDH isoenzymes were detected: LDH1, LDH2, LDH3, and LDH4. A definite metabolic trend of their changes in different stages of the disease was determined. LDH1 activity was considerably increased in patients with stage III mitral stenosis who had complications in the postoperative period. This is evidence of unstable compensation in patients of this group and may indicate the possible development of complications in the early postoperative period.