1- complete left bundle branch block:
– The electrical impulses will go from right to left
– QRS> 0.12 s (incomplete block -> 0.10 to 0.12)
– Deflection intrinsécoïde Delay (DIS) V6> 0,08s
– In V6 characteristic morphology: no wave q; Wide QRS with top tray or crocheted (RR ‘)
– In V1-V3: negativity wide QRS (rS, QS)
– The QRS axis is usually normal
2- complete right bundle branch block:
– QS time> 0.12 s (incomplete block -> 0.10 to 0.12)
– DIS delay> 0.08 s (0.04 to 0.07 s in case of in-full block) in V1-V2
– Morphology QRS in V1-V2 appearance RSR ‘ISR’ and rR ‘(R wave broad and late in cases of full block).
– In V5-V6 S wave (large in cases of full block)
– QRS axis is usually normal (sometimes deviated to the right)