Beat-to-beat QT interval variability in the 12 lead ECG

Beat-to-beat QT interval variability (QTV) is a marker of ventricular repolarization lability. Increased QTV has been associated ith cardiac mortality. The aim of this paper was to investigate QTV in the 12-lead ECG and the potential effect of age. Short-term ECGs (2 mins) of 48 healthy males ere studied. Beat-to-beat QTV as measured in each lead by using Berger's template-stretching algorithm. We observed significant differences in QTV of different leads (ANOVA test: p <; 0.0001). In addition, e investigated the effect of age by dichotomizing the data set based on the median age. Two-ay ANOVA showed no significant differences in QTV of older males compared to younger males. In conclusion, the magnitude of QTV depends on the lead selected for measurement.