In myocardial infarction, which biomarker is elevated?

In myocardial infarction, which biomarker is elevated?

• A. III only
• B. I, III
• C. I, II, III
• D. I, II, III, IV

Answer: (A)

In myocardial infarction, heart muscle cells release substances into the blood when they die, and the most informative single marker is troponin I because it is highly specific to cardiac tissue and stays elevated for a longer period. Troponin I rises within a few hours, peaks around 12–24 hours, and can remain elevated for several days, making it a reliable indicator of myocardial injury. Other markers like CK-MM or myoglobin can also rise, but they are less specific (myoglobin rises early but isn’t unique to the heart, CK-MM can come from other muscle sources), so troponin I is the best single biomarker to indicate an MI. If the list labels this marker as the only elevated one, that aligns with why it’s the correct choice.

In myocardial infarction, heart muscle cells release substances into the blood when they die, and the most informative single marker is troponin I because it is highly specific to cardiac tissue and stays elevated for a longer period. Troponin I rises within a few hours, peaks around 12–24 hours, and can remain elevated for several days, making it a reliable indicator of myocardial injury. Other markers like CK-MM or myoglobin can also rise, but they are less specific (myoglobin rises early but isn’t unique to the heart, CK-MM can come from other muscle sources), so troponin I is the best single biomarker to indicate an MI. If the list labels this marker as the only elevated one, that aligns with why it’s the correct choice.