Figure3
A: During low output pacing at near‐field, SLBBP capturing only the LBB and the excitation is conducted forward through the LBB.B: As output increasing, the SLBBP is converted to NSLBBP which causing a fusion of excitation of the LV and the adjacent local septal myocardium around the LBB by capturing the LBB area. C: LBBP might bypass the block of RBB through TF/FTI (dashed line) and eventually activate RBB with no paced morphology of RBBB. D:Excitation is conducted forward through the LBB and Purkinje fibers to activate the LV, meanwhile it reversely conducts to AVN and then recruit the RBB. E: TF/FTI (dashed line) may also exist within HB, connecting LBB and RBB transversely, which can transmit the retrograde excitation of LBB to RBB and then capture RBB. AVN = atrioventricular node; HB = His bundle; RBB = right bundle branch; LPF = left posterior fascicular; LAF = left anterior fascicular; TF = transverse interconnection fibers; FTI = functional transverse interconnection; RV = right ventricle; LV = left ventricle; IVS = interventricular septum