The QT interval is the time from the beginning of the QRS complex, representing ventricular depolarization, to the end of the T wave, resulting from ventricular repolarization. The normal QT ...

Whereas someone exhibiting marked prolongation of the QT interval with QTc exceeding 500 ms who was just externally defibrillated from torsades de pointes while swimming poses negligible diagnostic ...

the QT interval corrected for heart rate (QTc interval) actually increased by 50 ± 30 ms. By contrast, the QT interval did not decrease in patients with LQTS (it lengthened by 4 ± 34 ms ...

Due to the heart rates effects, the corrected QT interval (QTc) is frequently used. The QTc is considered prolonged if greater than 450 ms in males and 470 in females and is calculated using the ...