Impaired exercise capacity predicts sudden cardiac death in a low-risk population: enhanced specificity with heightened T-wave alternans
| Autor: | Kjell Nikus, Mikko Minkkinen, Tiit Kööbi, Väinö Turjanmaa, Mika Kähönen, Johanna Leino, Jari Viik, Terho Lehtimäki, Rami Lehtinen, Richard L. Verrier, Tuomo Nieminen |
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| Rok vydání: | 2009 |
| Předmět: |
Male
medicine.medical_specialty Time Factors Heart disease Population Physical exercise Sudden death Metabolic equivalent Sudden cardiac death Electrocardiography Risk Factors Internal medicine medicine Humans education Finland Retrospective Studies education.field_of_study Exercise Tolerance business.industry Cardiorespiratory fitness Arrhythmias Cardiac General Medicine T wave alternans Middle Aged medicine.disease Prognosis Survival Rate Death Sudden Cardiac Population Surveillance Physical therapy Cardiology Exercise Test Female business Follow-Up Studies |
| Zdroj: | Annals of medicine. 41(5) |
| ISSN: | 1365-2060 |
| Popis: | Because sudden cardiac death (SCD) is due to cardiac electrical instability, we postulated that prediction of this mode of death by exercise capacity will be enhanced by combined assessment with T-wave alternans (TWA), an index of repolarization abnormality.The Finnish Cardiovascular Study enrolled consecutive patients (n=2,044) with a routine clinically indicated exercise test. Exercise capacity was measured in metabolic equivalents (METs) and TWA by time-domain modified moving average method.During 47.2+/-12.8-month follow-up (mean+/-SD) 120 patients died; 58 were cardiovascular deaths, and 29 were SCD. In multivariate analysis after adjustment for sex, age, smoking, use of beta-blockers, as well as other common coronary risk factors, the relative risk of patients whose exercise capacity was depressed (MET8) was 8.8 (95% CI 2.0-38.9, P=0.004) for SCD. The combination of low exercise capacity (MET8) and elevated TWA (or =65 microV) yielded relative risks for SCD of 36.1 (6.3-206.0, P0.001), for cardiovascular mortality of 21.1 (6.7-66.2, P0.001), and for all-cause mortality of 7.8 (3.5-17.4, P0.001) over patients with neither factor.Reduced exercise capacity, particularly in combination with heightened TWA, indicating enhanced cardiac electrical instability, powerfully predicts risk for SCD in patients referred for exercise testing. |
| Databáze: | OpenAIRE |
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