Which lab markers are elevated during a myocardial infarction?

Which lab markers are elevated during a myocardial infarction?

• A. Hemoglobin and hematocrit
• B. ALT and AST
• C. Troponin and CK-MB
• D. Creatinine and BUN

Answer: (C)

During a myocardial infarction, heart muscle cells are damaged and release cardiac-specific proteins into the bloodstream. Troponin (I and T) and CK-MB are the best indicators because they are highly specific to cardiac tissue. Troponin rises within a few hours after injury and remains elevated for days, making it the most sensitive and specific test for acute MI. CK-MB also rises after injury, typically within 3–12 hours, and returns to baseline in about 24–48 hours, which helps with timing and detecting reinfarction. The other markers don’t reflect heart muscle injury: hemoglobin and hematocrit measure blood’s oxygen-carrying capacity, ALT and AST are liver enzymes (and can rise for non-cardiac reasons), and creatinine and BUN assess kidney function. So troponin and CK-MB are the elevated markers in myocardial infarction.

During a myocardial infarction, heart muscle cells are damaged and release cardiac-specific proteins into the bloodstream. Troponin (I and T) and CK-MB are the best indicators because they are highly specific to cardiac tissue. Troponin rises within a few hours after injury and remains elevated for days, making it the most sensitive and specific test for acute MI. CK-MB also rises after injury, typically within 3–12 hours, and returns to baseline in about 24–48 hours, which helps with timing and detecting reinfarction. The other markers don’t reflect heart muscle injury: hemoglobin and hematocrit measure blood’s oxygen-carrying capacity, ALT and AST are liver enzymes (and can rise for non-cardiac reasons), and creatinine and BUN assess kidney function. So troponin and CK-MB are the elevated markers in myocardial infarction.