Wide QRS duration is-
a wide qrs complex by definiton is more than 120 ms The QRS complex duration is wide (>0.12 seconds or 3 small boxes) in every lead. Causes of a widened QRS complex include right or left BBB, pacemaker, hyperkalemia, ventricular preexcitation as is seen in Wolf-Parkinson-White pattern, and a ventricular rhythm. Ref Harrison 20th edition pg 1576
>0.8sec
>0.9sec Pattern)
>.12sec
All the above
C.V.S