Where, Oh Where Has the MB Gone?

In 1959 Ebashi et al. reported that plasma creatine kinase activity was elevated in patients with skeletal-muscle injury,1 and in 1960 Dreyfus et al. reported similar findings in patients with acute myocardial infarction.2 The increased diagnostic specificity for myocardial infarction afforded by assay of the MB isoenzyme was appreciated by Van der Ween and Willebrands in 1966.3 Measurement of plasma MB creatine kinase every 8 to 12 hours for 24 to 48 hours after a suspected myocardial infarction is now more commonly performed than the traditional daily measurements of lactic dehydrogenase, serum aspartate aminotransferase and total creatine kinase. Plasma MB . . .