Why is ongoing unstable angina an absolute contraindication to symptom-limited exercise testing?

Why is ongoing unstable angina an absolute contraindication to symptom-limited exercise testing?

• A. Chest pain only during exertion.
• B. Symptoms disappear with rest.
• C. Symptoms at rest indicate active myocardial ischaemia that may worsen with exertion.
• D. Asymptomatic.

Answer: (C)

Unstable angina means there is ongoing myocardial ischemia. A symptom-limited exercise test is designed to provoke ischemia under controlled, monitored conditions, but it assumes the heart isn’t actively ischemic at rest. If ischemia is already present at rest or with minimal activity, as in unstable angina, adding exercise increases the heart’s oxygen demand and can push the ischemia into a dangerous range, risking serious events like sustained arrhythmias, larger myocardial infarction, or hemodynamic collapse. That’s why this scenario is an absolute contraindication to performing an exercise test. The other descriptions point to stable or resolved conditions (pain only with exertion, symptoms that disappear with rest, or no symptoms), which do not indicate ongoing instability and aren’t the reason for contraindicating exercise testing.

Unstable angina means there is ongoing myocardial ischemia. A symptom-limited exercise test is designed to provoke ischemia under controlled, monitored conditions, but it assumes the heart isn’t actively ischemic at rest. If ischemia is already present at rest or with minimal activity, as in unstable angina, adding exercise increases the heart’s oxygen demand and can push the ischemia into a dangerous range, risking serious events like sustained arrhythmias, larger myocardial infarction, or hemodynamic collapse. That’s why this scenario is an absolute contraindication to performing an exercise test.

The other descriptions point to stable or resolved conditions (pain only with exertion, symptoms that disappear with rest, or no symptoms), which do not indicate ongoing instability and aren’t the reason for contraindicating exercise testing.