Which statement correctly distinguishes myocardial infarction from angina?

Which statement correctly distinguishes myocardial infarction from angina?

• A. MI is death of cardiac tissue due to lack of oxygen. Angina is chest pain due to insufficient oxygen supply to the heart muscle.
• B. MI pain is always relieved by rest; Angina pain is not related to exertion.
• C. MI occurs only during exercise; Angina occurs during rest.
• D. MI improves with nitroglycerin; Angina does not.

Answer: (A)

The main idea is tissue viability: myocardial infarction means heart muscle tissue has died from a lack of oxygen, while angina is chest pain caused by temporary, reversible insufficient oxygen to the heart muscle. This makes the statement correct because an MI represents irreversible cell death due to sustained ischemia, whereas angina involves reversible ischemia without immediate tissue death. Angina pain is commonly triggered by activity or stress and tends to improve with rest and with nitroglycerin, reflecting its reversible nature. In contrast, MI pain does not reliably disappear with rest or nitroglycerin, since the tissue damage is already underway. The other options describe scenarios that don’t fit the fundamental difference between dead tissue and reversible ischemia, or imply that nitroglycerin reliably cures an MI, which isn’t the case.

The main idea is tissue viability: myocardial infarction means heart muscle tissue has died from a lack of oxygen, while angina is chest pain caused by temporary, reversible insufficient oxygen to the heart muscle. This makes the statement correct because an MI represents irreversible cell death due to sustained ischemia, whereas angina involves reversible ischemia without immediate tissue death. Angina pain is commonly triggered by activity or stress and tends to improve with rest and with nitroglycerin, reflecting its reversible nature. In contrast, MI pain does not reliably disappear with rest or nitroglycerin, since the tissue damage is already underway. The other options describe scenarios that don’t fit the fundamental difference between dead tissue and reversible ischemia, or imply that nitroglycerin reliably cures an MI, which isn’t the case.