Variability of QT interval dispersion in healthy subjects

Evaluation of dynamic changes of QT dispersion (QTd) during Holter monitoring would have applicability to clinical practice. However, the analysis of QTd variability on Holter ECG recordings has not yet been reported. We are now able to perform time and spectral domain analysis of QTd variability on Holter recordings using a homemade analyzer. An automatic interactive algorithm performed the analysis of the QRS-T complexes and measured QT duration from Holter recorded X, Y and Z leads in 10 healthy subjects. QTd was calculated as the difference between the longest and the shortest QT interval, measured on each simultaneous 3-lead ECG recording. Whether evaluation of QTd variability is of clinical significance needs further evaluation, especially when high risk patients are assessed.