Serum enzyme determinations in the diagnosis of acute myocardial infarction: an update

Area of Science:

• Clinical Biochemistry
• Cardiology
• Diagnostic Medicine

Background:

• Serum creatine kinase-MB (CK-MB) and lactate dehydrogenase isoenzyme 1 (LD-1) are established biomarkers for acute myocardial infarction (AMI).
• Elevated CK-MB can occur due to skeletal muscle release, and LD-1 is found in erythrocytes and renal cortex, limiting their specificity for myocardial injury.
• Accurate differential diagnosis of AMI requires reliable methods to distinguish cardiac from non-cardiac sources of these enzymes.

Purpose of the Study:

• To evaluate the utility of CK-MB and LD-1 in diagnosing acute myocardial infarction.
• To highlight the limitations of serum CK-MB and LD-1 levels alone in diagnosing myocardial injury.
• To establish electrophoresis as the definitive method for CK and LD isoenzyme analysis in clinical practice.

Main Methods:

• Electrophoresis was employed as the gold standard method for CK and LD isoenzyme separation and identification.
• Serum samples were analyzed to assess CK-MB and LD-1 levels.
• Visual interpretation of electrophoretic results was utilized for quality control and diagnostic assessment.

Main Results:

• Electrophoresis provides accurate differentiation of CK and LD isoenzymes, overcoming limitations of total serum activity measurements.
• The technique is suitable for both small and large laboratories due to its visual interpretability and lack of need for extreme analytic sensitivity.
• Electrophoresis offers clinically useful and acceptable results for diagnosing myocardial infarction.

Conclusions:

• Electrophoresis is the method of choice and final arbiter for CK and LD isoenzyme analysis.
• Visual interpretation of electrophoresis aids in quality control and makes the technique adaptable for diverse laboratory settings.
• Electrophoretic analysis of CK-MB and LD-1 provides reliable diagnostic information for acute myocardial infarction.