[Macro-CK-BB-emia: a rare differential diagnostic problem in the early stage of infarct]

In the early phase of acute myocardial infarction the determination of the creatinkinase-isoenzyme CK-MB has a high diagnostic value. In everyday laboratory routine the CK-MB-immunoinhibition test is most widely used. In rare cases it can lead to spuriously high and therefore false positive CK-MB values. Two patients with suspected acute myocardial infarction are presented. The laboratory findings showed in both cases very high CK-MB-activities, values significantly above the differential diagnostic borderline of 6%. The course of the CK-activity and additional qualitative laboratory tests led to the diagnosis of macro-CK-BB-emia.