[Exercise-induced ST segment shift in vasospastic angina with special reference to comparisons between treadmill and...

Area of Science:

• Cardiology
• Exercise Physiology

Background:

• Vasospastic angina is characterized by coronary artery spasm.
• Assessing the diagnostic accuracy of different exercise tests is crucial for managing this condition.

Purpose of the Study:

• To compare the efficacy of treadmill exercise (TM) versus bicycle ergometer exercise (EM) in provoking coronary artery spasm.
• To evaluate differences in cardiovascular responses and ST segment shifts between TM and EM in patients with vasospastic angina.

Main Methods:

• Sixty-seven patients with confirmed vasospastic angina underwent both TM and EM on the same day.
• Multistage, symptom-limited exercise protocols were used, with EM in the morning and TM in the afternoon.
• Coronary artery spasm was assessed via angiography, and ST segment changes (elevation/depression) were monitored during exercise.

Main Results:

• Heart rates were higher during TM, while systolic and diastolic blood pressures were higher during EM at peak exercise.
• Exercise-induced ST elevation was significantly more frequent during TM (19%) compared to EM (9%).
• Exercise-induced ST depression occurred more frequently during TM (40%) than EM (19%), particularly in patients without significant coronary lesions.

Conclusions:

• Treadmill exercise appears to provoke coronary spasm more frequently than bicycle ergometer exercise in patients with vasospastic angina.
• The enhanced autonomic nervous system activity and coronary perfusion during TM may contribute to the higher incidence of spasm.
• Further research is needed to elucidate the precise mechanisms underlying these observed differences.