Unusual ECG responses to exercise stress testing

Area of Science:

• Cardiology
• Diagnostic Electrocardiography

Background:

• Coronary artery disease (CAD) management often involves exercise stress testing (EST).
• Electrocardiogram (ECG) changes during EST typically indicate myocardial ischemia.

Observation:

• A patient with CAD presented with transient ST-segment depression, right bundle branch block (RBBB), left anterior hemiblock, ST-segment elevation, and prominent T-waves during EST.
• The ST-segment elevation amplitude was influenced by the presence and resolution of RBBB.
• Unusual T-wave morphology, typically seen in acute myocardial infarction, persisted late into the recovery phase.

Findings:

• Cardiac enzymes were negative post-EST, ruling out acute myocardial infarction.
• Coronary arteriography identified a stenotic left anterior descending artery.
• The study documents a novel combination of ECG findings during EST in a patient with significant coronary artery disease.

Implications:

• Severe myocardial ischemia during EST can manifest with a diverse range of ECG patterns, some previously unreported.
• These ECG changes suggest a common pathophysiological pathway between exercise-induced ischemia and early myocardial infarction.
• This case expands the understanding of ECG manifestations in severe, stress-induced cardiac ischemia.