Assessment of serum myoglobin as a marker for acute myocardial infarction.

The reliability of serum myoglobin as a marker for acute myocardial infarction was evaluated in 157 consecutive coronary-care admissions. Admission myoglobin was elevated in 47 of 52 patients with acute infarction. Excluding those patients who presented later than 24 hr after symptom onset, only one patient with acute infarct had a normal admission myoglobin. In 22 of 105 patients with no infarct, myoglobin was elevated in association with angina, congestive heart failure, arrhythmias, and renal insufficiency. The detection of acute infarction by serum myoglobin measurement equals that of serial serum creatine phosphokinase isoenzymes (CPK-MB) by electrophoresis, but an elevated myoglobin is not specific for what is now considered clinically significant myocardial infarction.