僧帽弁置換術後の血清酵素変動—急性心筋硬塞との対比検討

Changes in serum enzyme activities after mitral valve replacement:Comparison with acute myo-cardial infarction

　血清酵素学的方法は，循環器病学の領域では急性心筋硬塞（AMI）の診断に最も広く利用されている。他方，外科的侵襲（殊に心手術）に際して，時に心筋硬塞を合併することが知られており，perioperative myocardial—infarction　（PMI）と呼ばれている^1）〜8）。心手術後のPMIの合併頻度は，4〜20％と報告者により異なるが，一般に重症冠動脈疾患を有する症例の手術時に合併頻度が高いとされている^1）〜4）。しかし，心手術後PMIにおける酵素法の診断的意義に関しては一致した見解がなく，従って心手術そのものが術後血清酵素動態に如何なる影響を与えるかを把握しておくことはきわめて重要である。　本文では僧帽弁置換術（MVR）を施行した患者を対象として術後酵素活性値の経時変動を追跡し，心手術による心筋傷害度を観察すると共に，同時期に経験したAMI群のそれと比較検討した。

In order to estimate the surgically induced myocardial damage, serial determination of serum enzyme activities was performed in 11 patients undergoing mitral valve replacement (MVR). The results were compared with the correspond-ing enzyme activities in 11 patients with acute myocardial infarction (AMI). Perioperative myo-cardial infarction was excluded on the basis of clinical course and serial electrocardiography. In both groups, CK, CK-MB, GOT, and HBD were measured every 6 hours for 2 days after opera-tion or from the onset of chest pain, followed by daily measurement for 6 days.

Peak activities of CK, CK-MB, GOT, and HBD in MVR group were 2191±612, 110+18,169+24, and 920±64 IU/L (mean±S. E. M.), respectively. These values were equivalent to 1.1, O.2, O.3, and O. 6-folds of those in AMI group, signifying that the elevation of latter three enzymes was smaller in MVR than in AMI, in the presence of of similar increase in CK activity. Time course of enzyme activity following cardiac surgery was characterized by 1) shortening of peak activity time in all enzymes except CK, 2) delay of return-ing to normal activities of GOT and HBD, due presumably to additional enzymes release from the liver, and 3) early appearance and rapid disappearance of CK-MB. Peak activities of re-spective enzyme were not significantly correlated with durations of cardiopulmonary bypass and aortic cross-clamping and operation time. There were good correlations between peak activities of CK and GOT in both groups.