A 68-year-old male is in an unconscious state after a car crash. Blood tests show elevated enzyme levels that are explained by injuries sustained in the crash rather than a myocardial infarction. Which statement best describes these findings?

A 68-year-old male is in an unconscious state after a car crash. Blood tests show elevated enzyme levels that are explained by injuries sustained in the crash rather than a myocardial infarction. Which statement best describes these findings?

• A. The man had a myocardial infarction, which caused the accident.
• B. The elevated results are from the skeletal muscle injuries sustained in the car crash.
• C. The elevated results are a combination of the car crash injuries and a myocardial infarction.
• D. The elevated total CK and CK-MB results indicate a single source.

Answer: (B)

The key idea is that enzyme elevations in the blood come from the tissue that was damaged, and different tissues release their characteristic enzymes. In this scenario, severe skeletal muscle injury from the car crash can release large amounts of CK into the blood, including CK-MM, and can also raise CK-MB when muscle damage is extensive. This explains why enzyme levels are elevated without invoking a myocardial infarction. If a heart attack were the cause, you’d expect a pattern more specific to cardiac injury and typically additional markers like troponins would be involved. So the best statement is that the elevated results come from skeletal muscle injuries sustained in the crash, not from a heart attack.

The key idea is that enzyme elevations in the blood come from the tissue that was damaged, and different tissues release their characteristic enzymes. In this scenario, severe skeletal muscle injury from the car crash can release large amounts of CK into the blood, including CK-MM, and can also raise CK-MB when muscle damage is extensive. This explains why enzyme levels are elevated without invoking a myocardial infarction. If a heart attack were the cause, you’d expect a pattern more specific to cardiac injury and typically additional markers like troponins would be involved. So the best statement is that the elevated results come from skeletal muscle injuries sustained in the crash, not from a heart attack.