[Diagnosis and quantitative evaluation of irreversible myocardial damage by the cumulative activity of creatine phosphokinase MB isoenzyme in heart surgery patients].

In 185 patients after different cardiosurgical operations a postoperative follow-up study (after 3 hours) of the activity of MB creatinephosphokinase (CPK) was carried out. The cumulative activity of MB CPK was calculated (Q MB CPK) according to a modified Shell-Sobel formula. Trends in the type of curve changes of activity MB CPK were established and used to isolate three discrete levels of Q MB CPK (zero , average and high). The high level of MB CPK over 14.0 Eq was found only in patients with the intraoperational myocardial infarction, which in 13 cases (92%) was confirmed at the autopsy. Among patients with the average of zero level of Q MB CPK no myocardial infarction was found at autopsy (15 patients). The level of Q MB CPK did not depend on the surgical traumatism of myocardium. Zero level of Q MB CPK was found in 76% of patients after resection of the aneurysm of the left ventricle, and in 54% after valvular prosthesis. Determination of MB CPK is a specific and sensitive method of diagnosis of intraoperational myocardial infarctions. This method can be used in any cardiosurgical procedures.