[The change of creatine kinase bb isozyme in patients undergoing mitral value replacement--comparison with creatine kinase MB and MM isozymes].

By using highly sensitive enzyme immunoassay method recently developed, concentrations of the three forms of cytoplasmic creatine kinases (CK-BB, CK-MB and CK-MM) were determined in blood plasma samples serially taken from 18 patients, who received mitral valve replacement. Plasma CK-BB levels, that were 0.64 +/- 0.32 ng/ml at the beginning of anesthesia, increased sharply after reperfusion reaching peak levels (23.3 +/- 7.56 ng/ml) at 2 hours after reperfusion, and then decreased rapidly. The response of CK-BB in plasma was more rapid and sensitive than that of CK-BB or CK-MM. The CK-BB concentrations were significantly higher in coronary sinus samples than in arterial samples. These results suggest that the major portion of elevated plasma CK-BB levels at early phase after reperfusion were considered to be derived from the heart muscle.