title: Laboratory diagnosis of acute myocardial infarct: usefulness of determination of lactate dehydrogenase (LDH)-1 level and of ratio of LDH-1 to total LDH.
abstract: Recent development of an antibody to the M subunit of lactic dehydrogenase (LDH) allows the rapid isolation and measurement of LDH-1 levels. I and my colleagues studied 101 consecutive patients admitted to the hospital for possible acute myocardial infarct (AMI). The LDH-1 level was 100 IU/L or more, and the ratio of LDH-1 to total LDH (LDH-1/LDH-T ratio) was 0.40 or higher, during the course of illness in 93% of the patients with AMI. The specificity was 95% and the positive predictive value, 86%. These two criteria were met eight to 24 hours after the appearance of symptoms, and often persisted seven to 14 days. Measurement of LDH-1 level and LDH-1/LDH-T ratio is a useful adjunct in the laboratory diagnosis of AMI.
mesh_terms: D000328:Adult; D001322:Autoanalysis; D004796:Clinical Enzyme Tests; D003402:Creatine Kinase / Q000097:blood; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007120:Immunochemistry; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000097:blood*; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis*
chemical_list: D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase