[Value of phosphohexose isomerase (PHI) determination in myocardial infarct]

The biochemical diagnosis of myocardial infarction is based mainly on the enzyme levels of glutamino-oxalic transaminase (SGOT), lactic dehydrogenase (LDH), and creatine-phosphokinase (CPK). The authors have compared the level of phospho-hexo-isomerase (PHI) with the levels of the three other enzymes mentioned above in 20 cases of recent myocardial necrosis. From their study it appears that PHI activity follows essentially the same pattern as that of CPK, and has no particular advantage; indeed, it is limited by its later appearance and its lower maximum level compared with CPK. Finally, because of its lack of specificity, the practical importance of PHI measurement in the clinical diagnosis of myocardial infarction is small.