What does marked ST displacement during a Symptom-Limited Test suggest?

What does marked ST displacement during a Symptom-Limited Test suggest?

• A. It indicates dehydration.
• B. It indicates a normal response to exercise.
• C. It suggests myocardial ischemia; may be monitored if patient stable.
• D. It indicates a technical artifact.

Answer: (C)

Marked ST displacement during a symptom-limited exercise test signals myocardial ischemia. As the heart works harder, its oxygen demand increases; if the coronary blood supply can’t meet this demand, regions of the heart become ischemic and the ST segment on the ECG shifts abnormally. This is not a normal exercise response, and it raises concern for significant coronary disease. The usual management is to stop the test and monitor the patient; if they remain stable, further evaluation with imaging or coronary assessment is considered. Dehydration wouldn’t produce this pattern, a normal response wouldn’t show such ST changes, and while artifacts can mimic ECG findings, a genuine ischemic pattern associated with symptoms is taken seriously and investigated.

Marked ST displacement during a symptom-limited exercise test signals myocardial ischemia. As the heart works harder, its oxygen demand increases; if the coronary blood supply can’t meet this demand, regions of the heart become ischemic and the ST segment on the ECG shifts abnormally. This is not a normal exercise response, and it raises concern for significant coronary disease. The usual management is to stop the test and monitor the patient; if they remain stable, further evaluation with imaging or coronary assessment is considered. Dehydration wouldn’t produce this pattern, a normal response wouldn’t show such ST changes, and while artifacts can mimic ECG findings, a genuine ischemic pattern associated with symptoms is taken seriously and investigated.