How does a myocardial infarction primarily differ from stable angina?

How does a myocardial infarction primarily differ from stable angina?

• A. MI is reversible ischemia; angina is tissue death
• B. MI results from sudden complete occlusion causing myocardial tissue death; angina is chest pain due to transient ischemia during exertion or stress
• C. MI occurs only at rest; angina only with exertion
• D. MI responds immediately to rest; angina does not

Answer: (B)

The main distinction is that myocardial infarction involves irreversible injury to heart muscle due to a sudden, complete blockage of a coronary artery, causing tissue death, whereas stable angina is reversible ischemia from temporarily reduced blood flow during exertion or stress. This makes the correct explanation the best: an acute MI happens when a plaque rupture leads to a sudden, complete occlusion, cutting off blood supply long enough to kill heart muscle in the area supplied by that artery. The damage is necrosis if the blockage persists. Stable angina, on the other hand, reflects transient, reversible ischemia—the heart isn’t getting enough blood only during increased demand, but there’s no permanent muscle death as long as blood flow is restored (by rest or medication). Why the other statements don’t fit: MI is not reversible ischemia and does not imply tissue death; angina-caused pain is due to transient ischemia, not tissue death. MI is not restricted to rest, and stable angina is typically triggered by exertion or stress and relieved with rest or nitroglycerin. Is that enough context to see how the two conditions differ in mechanism and outcome?

The main distinction is that myocardial infarction involves irreversible injury to heart muscle due to a sudden, complete blockage of a coronary artery, causing tissue death, whereas stable angina is reversible ischemia from temporarily reduced blood flow during exertion or stress.

This makes the correct explanation the best: an acute MI happens when a plaque rupture leads to a sudden, complete occlusion, cutting off blood supply long enough to kill heart muscle in the area supplied by that artery. The damage is necrosis if the blockage persists. Stable angina, on the other hand, reflects transient, reversible ischemia—the heart isn’t getting enough blood only during increased demand, but there’s no permanent muscle death as long as blood flow is restored (by rest or medication).

Why the other statements don’t fit: MI is not reversible ischemia and does not imply tissue death; angina-caused pain is due to transient ischemia, not tissue death. MI is not restricted to rest, and stable angina is typically triggered by exertion or stress and relieved with rest or nitroglycerin. Is that enough context to see how the two conditions differ in mechanism and outcome?