How does unstable angina differ from stable angina?

How does unstable angina differ from stable angina?

• A. Unstable angina occurs at rest or with increasing frequency/intensity, often due to plaque rupture; stable angina occurs with predictable exertion
• B. They are identical
• C. Unstable angina occurs with exertion; stable at rest
• D. Unstable angina is more severe and always at rest

Answer: (D)

The key idea is how the pattern and the underlying change in the coronary arteries distinguish unstable from stable angina. Unstable angina comes from an acute result of plaque rupture with partial thrombosis, causing sudden, unpredictable reductions in blood flow. This means episodes can occur at rest or with minimal activity, and their frequency, duration, or intensity typically increase over time. It’s not reliably relieved by rest or nitroglycerin, and it signals a high risk of progressing to a heart attack. Stable angina, by contrast, arises from a fixed narrowing of a coronary artery. The chest discomfort is predictable and usually triggered by exertion or emotional stress; it’s typically relieved by rest or nitroglycerin, and the pattern remains fairly constant over time. So the most accurate distinction centers on timing and predictability: unstable angina is changing and can happen at rest, indicating greater danger, while stable angina is exertional and relief-responsive. The idea that unstable angina is always at rest isn’t correct, since it can also occur with exertion but still represent instability due to evolving thrombosis.

The key idea is how the pattern and the underlying change in the coronary arteries distinguish unstable from stable angina. Unstable angina comes from an acute result of plaque rupture with partial thrombosis, causing sudden, unpredictable reductions in blood flow. This means episodes can occur at rest or with minimal activity, and their frequency, duration, or intensity typically increase over time. It’s not reliably relieved by rest or nitroglycerin, and it signals a high risk of progressing to a heart attack.

Stable angina, by contrast, arises from a fixed narrowing of a coronary artery. The chest discomfort is predictable and usually triggered by exertion or emotional stress; it’s typically relieved by rest or nitroglycerin, and the pattern remains fairly constant over time.

So the most accurate distinction centers on timing and predictability: unstable angina is changing and can happen at rest, indicating greater danger, while stable angina is exertional and relief-responsive. The idea that unstable angina is always at rest isn’t correct, since it can also occur with exertion but still represent instability due to evolving thrombosis.