A nurse is reviewing the laboratory values of a client who had a myocardial infarction 3 hr ago. The nurse should expect which of the following laboratory values to be elevated?

Rationale: A. Amylase is an enzyme primarily elevated in pancreatic disorders such as pancreatitis, not myocardial infarction. B. Unconjugated bilirubin is elevated in hemolysis or liver dysfunction. It is not a marker of myocardial injury. C. AST can be elevated after myocardial infarction, but it is nonspecific because it is also found in liver, skeletal muscle, and kidneys. It rises later and is not the most sensitive early marker. D. Troponin I is highly specific to cardiac muscle injury and increases within 3–6 hours after myocardial infarction, making it a primary early diagnostic marker. It remains elevated for 7–10 days, helping confirm myocardial injury.