Evaluation of enzyme tests in the diagnosis of heart disease∗

Quantitative assessment of the extent of myocardial infarction in the conscious dog by means of analysis of serial changes in serum creatine phosphokinase activity

“…There are several reasons for this: (a) enzyme activity appearing in serum after myocardial infarction may reflect release not only from myocardial cells but also from other components in the heart participating in the inflammatory response, skeletal muscle, liver, and other parenchymal tissues (20,21); (b) the magnitude of peak serum enzyme elevation depends not only on infarct size but also on the rate of release of enzyme into the circulation, the enzyme distribution space, and the rate of enzyme disappearance from the circulation (20,22); and (c) current morphologic techniques for measuring infarct size unavoidably lack precision (18,23,24) limiting the validity of conclusions dependent upon anatomic criteria.…”