Retrograde conduction of LBB activation
Previous studies have shown that there was the retrograde activation of the His bundle in the human heart 22-24, which was also confirmed by the retrograde His potential recorded in the process of determination of SLBBP 4. Zhang et al. had suggested that without RBBB or proximal LBBB, besides the stimulus conducts rapidly through the LBB and Purkinje fibers to activates LV, it reversely conducts to His bundle and then conducts forward through the RBB and Purkinje fibers to activates the RV 25. However, the process by which retrograde conduction of LBB activation overcomes structural barriers of longitudinal dissociation within His bundle to activate RBB is obscure and may be successful through AVN or TF/FTI. (Figure3 D&E) Even if it can, it is unknown whether it can recruit the distal RBBB or not.