Oxypurine release in cardiac disease. An indicator of general hypoxia in patients with cardiac arrest.

The excretion of hypoxanthine-xanthine and uric acid in urine and the concentrations in peripheral venous blood were determined in nine patients with cardiac arrest due to acute myocardial infarction (AMI), in ten control patients with AMI without cardiac arrest and in nine with angina pectoris. The patients with cardiac arrest showed a 6-fold increase in urinary excretion of hypoxanthine-xanthine 0-2 hours after cardiac arrest. No difference was observed in the uric acid excretion or the hypoxanthine-xanthine and uric acid concentrations in peripheral venous blood. The urinary excretion of hypoxanthine-xanthine increases considerably in connection with reversible cardiac arrest, indicating general tissue hypoxia. No relationship could be found between the duration of cardiac arrest and the increased hypoxanthine-xanthine excretion in the urine.