Serum myoglobin determination: laboratory and clinical evaluation.

Quality assurance examination of a commercially available radioimmunoassay kit for determination of serum myoglobin level conformed the measurement to be accurate, precise, and reproducible under all assay performance variables. Initial clinical evaluation in patients admitted to the Coronary Care Unit revealed comparable diagnostic parameters and earlier detection when compared with the present standard indicator of myocardial necrosis, creatine phosphokinase MB isoenzyme. Interpretation that an elevated myoglobin reflects acute myocardial infarction should be made only in the appropriate clinical context.