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Ventricular arrhythmias during exercise testing: mechanism, response to coronary bypass surgery and prognostic
Insights
Exercise-induced ventricular arrhythmias are linked to severe coronary artery disease and reduced heart function. However, these arrhythmias did not increase cardiac mortality in medically treated patients over 5.3 years.
Area of Science:
- Cardiology
- Exercise Physiology
Background:
- Ventricular arrhythmias during exercise testing are a concern in patients with coronary artery disease.
- Understanding their determinants and prognostic significance is crucial for patient management.
Purpose of the Study:
- To identify factors associated with exercise-induced ventricular arrhythmias (EI-VAs).
- To evaluate the prognostic value of EI-VAs in patients undergoing exercise testing and cardiac catheterization.
Main Methods:
- Retrospective analysis of 446 patients undergoing treadmill exercise testing and cardiac catheterization.
- Identification of 86 patients with EI-VAs.
- Correlation of EI-VAs with coronary artery disease severity, ejection fraction, and wall motion abnormalities.
Main Results:
- Prevalence of EI-VAs was 19% overall, rising to 30% in patients with 3-vessel or left main coronary artery disease.
- EI-VAs were associated with 3-vessel/left main disease, lower ejection fraction, ischemic ST depression, and wall motion abnormalities.
- Persistent EI-VAs post-surgery linked to preoperative severe wall motion abnormalities or residual ischemia.
Conclusions:
- Exercise-induced ventricular arrhythmias are markers of significant coronary artery disease and impaired cardiac function.
- In medically treated patients, EI-VAs were not associated with increased long-term cardiac mortality.
Abstract:
To investigate the determinants and prognostic significance of ventricular arrhythmias during exercise testing, 86 patients with such arrhythmias were identified from a consecutive series of 446 patients who underwent treadmill exercise testing and cardiac catheterization. The prevalence of these arrhythmias was 19% in the total group but increased to 30% in the 120 patients with 3-vessel or left main coronary artery disease. Patients with exercise-induced arrhythmias were more likely to have 3-vessel or left main coronary artery disease, a lower resting ejection fraction, greater than or equal to 2 mm of ischemic ST depression and more severe segmental wall motion abnormalities than patients without this finding (p less than 0.05). Repeat exercise testing in 22 patients with exercise-induced arrhythmias after coronary bypass surgery revealed that persistence of these arrhythmias was associated with either severe wall motion abnormalities preoperatively or residual ischemic ST depression during the post-operative exercise testing. At a mean follow-up period of 5.3 years, the presence of exercise-induced ventricular arrhythmias was not associated with increased cardiac mortality in the medically treated patients.