Angina pectoris occurs when:

Angina pectoris occurs when:

• A. myocardial oxygen supply exceeds the demand.
• B. one or more coronary arteries suddenly spasm.
• C. myocardial oxygen demand exceeds supply.
• D. a coronary artery is totally occluded by plaque.

Answer: (C)

Angina pectoris occurs when the heart muscle doesn’t receive enough oxygen to meet its workload. In other words, oxygen demand outstrips oxygen supply. When the heart is stressed by activity or stressors, the already narrowed or partially blocked coronary arteries can’t deliver enough blood, causing transient ischemia and chest pain. If a coronary artery suddenly spasms, that can cut off blood flow and trigger angina as well, since it temporarily reduces supply. However, a completely occluded artery due to plaque often leads to a heart attack, with ongoing damage rather than the typical, transient angina pattern.

Angina pectoris occurs when the heart muscle doesn’t receive enough oxygen to meet its workload. In other words, oxygen demand outstrips oxygen supply. When the heart is stressed by activity or stressors, the already narrowed or partially blocked coronary arteries can’t deliver enough blood, causing transient ischemia and chest pain.

If a coronary artery suddenly spasms, that can cut off blood flow and trigger angina as well, since it temporarily reduces supply. However, a completely occluded artery due to plaque often leads to a heart attack, with ongoing damage rather than the typical, transient angina pattern.