Relations between QRST Angle Cardiac Risk Factors and Mortality in the Third National Health and Nutrition Examination Survey (NHANES III)

摘要

On the surface electrocardiogram (ECG), an abnormally wide QRS|T angle reflects changes in regional action potential duration profiles and in direction of repolarization sequence which is thought to increase the risk of ventricular arrhythmia. We investigated the relationship between abnormal QRS|T angle and mortality in a nationally representative sample of individuals without clinically evident heart disease. We studied 7,052 participants ≥ 40 years of age in the Third National Health and Nutrition Examination Survey (NHANES III) with 12-lead ECGs. Individuals with self-report or ECG evidence of a prior myocardial infarction, QRS duration ≥120 msec, or history of heart failure were excluded. Borderline and abnormal spatial QRS|T angle were defined according to sex-specific 75^th and 95^th percentiles of frequency distributions. All-cause (n=1093 women, n=1191 men) and cardiovascular mortality (n=462 women, n=455 men) over 14 years was assessed through linkage with the National Death Index. In multivariable analyses, abnormal spatial QRS|T angle was associated with an increased hazard ratio (HR) for cardiovascular mortality in women (HR 1.82, 95% CI 1.05-3.14) and men (HR 2.21, 95% CI 1.32-3.68). An abnormal QRS|T angle was also associated with increased multivariable adjusted HRs for all-cause mortality in women (HR 1.30, 95% CI 0.95-1.78) and men (HR 1.87, 95% CI 1.29-2.7). Borderline QRS|T angle was not associated with increased risk for all-cause or cardiovascular mortality. In conclusion, abnormal QRS|T angle, as measured on a 12-lead ECG, was associated with increased risk for cardiovascular and all-cause mortality in this population-based sample without known heart disease.