[Changes in xanthine oxidase activity in patients with circulatory failure].

As many as 76 patients suffering from inactive rheumatic fever associated with different stages of heart failure were examined for uricemia, diurnal uricosuria, and xanthine oxidase activity in blood serum. It was established that in rheumatic fever, the activity of xanthine oxidase increased even at the early stages of heart failure. The presence in some of the patient of the enzyme activation combined with hyperuricosuria and normal content of uric acid in blood serum suggests "latent" hyperuricemia. In patients with severe heart decompensation, there was an appreciable activation of xanthine oxidase, which correlated, as a rule, with high hyperuricemia. Activation of xanthine oxidase in patients with rheumatic fever evidences hyperproduction of uric acid. It is advisable that in such cases the uricodepressive treatment may be indicated.