T-wave alternans predicts mortality in a population undergoing a clinically indicated exercise test
Tuomo Nieminen1, Terho Lehtimäki, Jari Viik
1Department of Pharmacological Sciences, Medical School, University of Tampere, and Laboratory of Atherosclerosis Genetics, Department of Clinical Chemistry, Tampere University Hospital, Finland.
European Heart Journal
|July 27, 2007
Summary
T-wave alternans (TWA) measured during exercise tests effectively predicts mortality risk in the general population. This electrocardiographic marker identifies individuals at higher risk for sudden cardiac death and overall mortality.
Area of Science:
- Cardiology
- Clinical Electrophysiology
- Preventive Medicine
Background:
- T-wave alternans (TWA) is a marker of cardiac electrical instability.
- Predictive value of TWA in a general population undergoing exercise testing is not well established.
Purpose of the Study:
- To test the hypothesis that T-wave alternans (TWA) predicts mortality in a general population referred for a clinical exercise test.
Main Methods:
- 1037 patients undergoing exercise tests were included.
- Digital ECGs were analyzed for TWA using the modified moving average method.
- Risk stratification for all-cause, cardiovascular, and sudden cardiac death (SCD) was assessed.
Main Results:
- During follow-up, 59 deaths occurred, including 20 SCDs.
- Multivariate analysis revealed TWA > or = 65 microV significantly predicted SCD (RR 7.4), cardiovascular mortality (RR 6.0), and all-cause mortality (RR 3.3).
- These associations remained significant after adjusting for common risk factors.
Conclusions:
- Time-domain TWA analysis is a powerful predictor of mortality.
- TWA can effectively stratify risk in a general population undergoing clinical exercise testing.
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