Myoglobinemia in the early phase of acute myocardial infarction.

Close-meshed determinations of plasma myoglobin, creatine kinase, and its isoenzyme MB were carried out in nine patients admitted to the clinic less than 4 hours after the onset of symptoms in the course of acute myocardial infarction (AMI). Myoglobin clearly appears earlier (mean 2 hours and 30 minutes) in the plasma than creatine kinase (mean 4 hours and 15 minutes) and isoenzyme MB (mean 5 hours and 30 minutes after the onset of symptoms). During the first hours of AMI plasma myoglobin shows multiple peaks in all patients. Because this pattern is observed only with myoglobin but not with creatine kinase, it appears that myoglobin mirrors the early course of the necrosis more distinctly than creatine kinase. Plasma myoglobin was also found elevated after intramuscular injections and a high voltage accident. Myoglobinuria was not detectable after myocardial infarction.