The QT interval in the surface electrocardiogram (ECG) reflects the total duration of depolarization and repolarization of the ventricles. QT dispersion (QTd) represents non uniformity of regional myocardial ventricular repolarization and is reflected by differences of the QT interval duration between ECG leads. Both prolonged QT interval and increased QTd are predisposing factors to develop malignant ventricular arrhythmias .Prolonged QT interval is associated with cardiac arrhythmias and sudden death. Studies show that prolonged QT interval and increased  QT dispersion are predictors of cardiovascular mortality and all–cause mortality in patients with  type 1 and 2 Diabetes Mellitus^(1,2) and in the population of apparently healthy individuals .⁽³⁾