Normally, there is no electrical activity (flat ECG) between ventricular depolarization (reflected by the QRS complex) and repolarization (T wave), corresponding to the ST segment, because all ...

representing ventricular depolarization, is increased. Likewise, when the myocardium is abnormally thickened, and electrical activity takes longer to traverse throughout the whole heart ...

representing ventricular depolarization, to the end of the T wave, resulting from ventricular repolarization. The normal QT interval is controversial, and multiple normal durations have been reported.