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the period from the beginning of the QRS complex to the end of the T wave on an electrocardiogram. It reflects the refractory period of the heart. A long Q-T interval is associated with the life-threatening ventricular tachycardia known as torsades de pointes. Quinidine, procainamide, and disopyramide can lengthen the Q-T interval.
The time from Q wave (of QRS complex) to the end of the T wave as it can be measured on an electrocardiogram; corresponds to ventricular systole.
The representation on the electrocardiogram of ventricular depolarization and repolarization, beginning with the QRS complex and ending with the T wave.Synonym: Q-T segment
See also: interval