Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Myoglobin is a heme protein found in smooth and skeletal muscles. Serum myoglobin reflects a balance between intravascular release of myoglobin from muscle and renal clearance.
Previously serum myoglobin had been advocated as a sensitive marker for early acute myocardial injury (eg, acute myocardial infarction: AMI). However, more recent studies indicate that other newer markers (eg, troponin) provide superior diagnostic utility in detecting early myocardial injury.
Elevation of serum myoglobin may occur as a result of muscle trauma, resuscitation, myopathies, AMI, shock, strenuous body activity, or decreased elimination during renal insufficiency. Extreme elevations occur in rhabdomyolysis.
Assessing muscle damage from any cause
Elevated myoglobin levels are seen in conditions of acute muscle injury.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Elevation is nonspecific for acute myocardial infarction. The test is of no value in this regard in the presence of renal failure, rhabdomyolysis, extensive trauma, acute peripheral vascular occlusion, or after seizures.
Serum levels rise in renal insufficiency.
Results are unreliable in lipemic serum; specimens that cannot be cleared by ultracentrifugation will be rejected.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
< or =90 mcg/L
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Varki AP, Roby DS, Watts H, Zatuchni J: Serum myoglobin in acute myocardial infarction: a clinical study and review of the literature. Am Heart J 1978;96:680-688
2. Kallner A, Sylven C, Brodin U, et al: Early diagnosis of acute myocardial infarction. A comparison between chemical predictors. Scand J Clin Lab Invest 1989;49:633-639