Reference values of electrocardiogram repolarization variables in a healthy population.

ABSTRACT

INTRODUCTION: Reference values for T-wave morphology analysis and evaluation of the relationship with age, sex, and heart rate are lacking in the literature. In this study, we characterized T-wave morphology in a large sample of healthy individuals. METHOD: A total of 1081 healthy subjects (83% men; range, 17-81 years) were included. T-wave morphology variables describing the duration, area, slopes, amplitude, and distribution were calculated using 10-second digital electrocardiogram recordings. Multivariate regression was used to test for dependence of T-wave variables with the subject age, sex, and heart rate. RESULTS: Lead V5 (men vs women) T-wave variables were as follows amplitude, 444 versus 317 muV; area, 48.4 versus 33.2 ms mV; Tpeak-Tend interval, 94 versus 92 milliseconds; maximal descending slope, -5.15 versus -3.69 muV/ms; skewness, -0.24 versus -0.22; and kurtosis, -0.36 versus -0.35. Tpeak-Tend interval, skewness, and kurtosis were independent of age, sex, and heart rate (r(2) < 0.05), whereas Bazett-corrected QT-interval was more dependent (r(2) = 0.40). CONCLUSION: A selection of T-wave morphology variables is found to be clinically independent of age, sex, and heart rate, including Tpeak-Tend interval, skewness, and kurtosis.