Exercise-induced repolarization changes in patients with stable coronary artery disease
Panagiotis Korantzopoulos1, Konstantinos P Letsas, Zacharias Christogiannis
1Department of Cardiology, University of Ioannina School of Medicine, Ioannina, Greece. p.korantzopoulos@yahoo.gr
The American Journal of Cardiology
|December 15, 2010
Summary
Exercise increases repolarization dispersion in coronary artery disease (CAD) patients, even without ischemia. This finding suggests a higher risk of ventricular arrhythmias during physical activity for individuals with stable CAD.
Area of Science:
- Cardiology
- Electrophysiology
- Exercise Physiology
Background:
- Exercise can trigger ventricular arrhythmias in patients with coronary artery disease (CAD).
- Repolarization indexes like corrected QT (QTc), T peak-to-end (Tpe) interval, and Tpe/QT ratio are crucial for assessing arrhythmia risk.
- Understanding repolarization changes during exercise in stable CAD is vital for risk stratification.
Purpose of the Study:
- To investigate alterations in novel repolarization indexes during exercise stress testing in patients with stable coronary artery disease (CAD).
- To compare these changes with those observed in a control group without CAD.
Main Methods:
- Sixty-seven stable CAD patients and 68 controls underwent treadmill exercise stress testing (Bruce protocol).
- Repolarization indexes, including corrected QT (QTc) interval, T peak-to-end (Tpe) interval, and Tpe/QT ratio, were measured at baseline and peak exercise.
- Patients with evidence of ischemia during testing were excluded.
Main Results:
- In CAD patients, QTc interval, Tpe interval, and Tpe/QT ratio significantly increased from baseline to peak exercise (p <0.001, p <0.001, p = 0.015, respectively).
- In the control group, QTc interval showed no significant change, Tpe interval decreased (p = 0.05), and Tpe/QT ratio remained stable (p = 0.39).
- These findings indicate increased spatial repolarization dispersion during exercise in stable CAD patients, even with normal stress tests.
Conclusions:
- Exercise significantly increases spatial repolarization dispersion in patients with stable CAD, independent of inducible ischemia.
- Elevated repolarization dispersion during exercise may contribute to an increased risk of ventricular arrhythmias in this population.
- Novel repolarization indexes offer valuable insights into exercise-induced electrophysiological changes and arrhythmia risk in CAD patients.
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