Correlation of serum and urine enzyme activity in patients with acute myocardial infarction.

A correlation was made between the urinary excretion of GOT, GPT, LDH, HBD, and acid and alkaline phosphatase and their serum activity in 18 suspected cases of myocardial infarction. The diagnoses were made by a cardiologist without knowledge of the enzyme assays. The study included 2 cases of nontransmural infarction; 5 cases that had not sustained an infarction served as controls. Elevations of serum GOT, LDH, and HBD were found in 10 of 11 cases of transmural infarction, CPT and acid phosphatase in 5, and alkaline phosphatase in 7. Elevations in serum acid phosphatase were also found in the control group, and perhaps were related to the anticoagulation therapy. Urinary GOT and GPT activity was variable. Urinary LDH and HBD were elevated in 6 of the transmural infarction cases, usually when serum LDH and HBD activity was decreasing. Urinary acid phosphatase activity was essentially normal; but urinary alkaline phosphatase increased in 10 of the transmural infarction cases, and the average value remained high for more than 5 weeks. The only index that was elevated in all cases of acute transmural infarction was L-phenylalanine inhibition of urinary alkaline phosphatase activity.