Which finding during a Symptom-Limited Test most strongly suggests myocardial ischemia if the patient is stable?

Which finding during a Symptom-Limited Test most strongly suggests myocardial ischemia if the patient is stable?

• A. Absence of any ECG changes.
• B. An exaggerated hypertensive response without symptoms.
• C. Marked ST displacement during a Symptom-Limited Test.
• D. A normal blood pressure response.

Answer: (C)

During a symptom-limited exercise test, the strongest clue that the heart is not getting enough blood is seen on the ECG as changes in the ST segment. Marked ST displacement, typically downward depression with horizontal or downsloping ST segments, reflects subendocardial ischemia caused by the increasing workload outstripping coronary blood flow. This change is a direct, objective sign that ischemia is occurring even if the patient remains stable and without chest pain. In contrast, not seeing any ECG changes makes ischemia less likely, an exaggerated hypertensive response without symptoms is non-specific, and a normal blood pressure response by itself does not indicate ischemia. Therefore, the presence of marked ST displacement during the test best signals ischemia.

During a symptom-limited exercise test, the strongest clue that the heart is not getting enough blood is seen on the ECG as changes in the ST segment. Marked ST displacement, typically downward depression with horizontal or downsloping ST segments, reflects subendocardial ischemia caused by the increasing workload outstripping coronary blood flow. This change is a direct, objective sign that ischemia is occurring even if the patient remains stable and without chest pain.

In contrast, not seeing any ECG changes makes ischemia less likely, an exaggerated hypertensive response without symptoms is non-specific, and a normal blood pressure response by itself does not indicate ischemia. Therefore, the presence of marked ST displacement during the test best signals ischemia.