Mohamed Salih Background¶ QT is measured from the start of the Q-wave to the end of the T-wave (use the lead with the longest measurement) and is the time of ventricular depolarization + repolarization QTc is the corrected estimate of QT assuming a rate of 60 bpm since QT decreases with tachycardia and increases with bradycardia QTcF (Fridericia) + QTcB (Bazett) on ECG are different…