When electrical activity does not conduct through the His-Purkinje system, but instead travels from myocyte to myocyte, a longer time is necessary, and the QRS duration is widened. A widened QRS ...

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.

Second-degree AV block PR increment preceding a blocked P (Wenckebach) and narrow QRS Constant PR interval preceding blocked P PR increment (Wenckebach) preceding a blocked P and wide QRS 2:1 AV ...