1) Cardiac electrophysiology 
In cardiology, the QT interval is a measure of the time between the start of the Q wave and the end of the T wave in the heart`s electrical cycle. The QT interval represents electrical depolarization and repolarization of the ventricles. A lengthened QT interval is a marker for the potential of ventricular tachyarrhythmias like torsades de pointe....
Type: Term Definitions: 1. time from electrocardiogram Q wave to the end of the T wave corresponding to electrical systole.