[Dynamics of the QT interval]

Spatial and temporal inhomogeneity of ventricular repolarization has been associated with the susceptibility to development of malignant ventricular arrhythmias. QT interval and QT dispersion dynamically change depending on not only heart rate but also other various factors such as autonomic tone, gender, aging, electrolytes or some drugs. Several studies have demonstrated that the dynamic behavior in the QT interval and QT dispersion such as the beat-to-beat fluctuations or the diurnal variation were altered in the setting of the abnormal pathophysiological conditions. Although the assessment of QT dynamicity remains a challenging issue from a technical point of view, it may provide the important information for identifying patients at potential risk of ventricular arrhythmias.