Exercise ECG testing using different protocols in asymptomatic healthy young subjects

Area of Science:

• Cardiology
• Exercise Physiology
• Diagnostic Electrocardiography

Background:

• Exercise stress testing is a common diagnostic tool.
• Interpreting electrocardiographic (ECG) changes during exercise requires careful consideration.
• Distinguishing true cardiac events from benign findings is critical.

Purpose of the Study:

• To investigate the occurrence and nature of ST-T abnormalities during symptom-limited exercise in healthy young males.
• To assess the diagnostic significance of exercise-induced ECG changes.
• To evaluate the impact of different exercise protocols and monitoring on findings.

Main Methods:

• Thirty-four healthy young males underwent symptom-limited exercise testing using the Bruce protocol on a treadmill.
• ECG monitoring was employed during exercise.
• A subset of participants, along with additional volunteers, were later exercised on a Master's stepper without continuous ECG monitoring.

Main Results:

• Two subjects exhibited hyperventilation-induced labile repolarization ST-T abnormalities.
• Five additional subjects showed exercise-induced ST changes (4 with upsloping ST depression, 1 with horizontal ST depression).
• These changes were asymptomatic, transient (reverting within 30 seconds), and considered probable false positives. No changes were observed on the Master's stepper, potentially due to lack of continuous ECG monitoring.

Conclusions:

• Transient ST-T abnormalities during exercise in healthy young males may represent probable false positives.
• The Bruce protocol on a treadmill may elicit more ECG changes than the Master's stepper.
• Continuous ECG monitoring is essential for accurate interpretation of exercise-induced ECG changes.