Ventricular tachycardia refers to a wide QRS complex heart rhythm — that is, a QRS duration beyond 120 milliseconds — originating in the ventricles at a rate of greater than 100 beats per minute.

A narrow complex tachycardia results with P wave morphologies that are different than normal sinus P waves. The QRS complex can be wide if aberrancy is present (ie, right or left bundle branch ...