Purkinje Fibers in Canine False Tendons: New Anatomical and Electrophysiological Findings

Figure 6

The schematics of our hypothesis about the possible reentrant circuits of idiopathic left fascicular ventricular tachycardia. (a) The anatomical structure and conduction pattern of the Purkinje network during sinus rhythm. During sinus rhythm, the main branch of His-Purkinje system (the apical hierarchy) exhibited antegrade activation sequence (P2, red lines and arrows) and then retrogradely activated the Purkinje network on the basal hierarchy (P1, blue lines and arrows). The green line and arrows represented the tiny FT between the Purkinje network on the same basal hierarchy or different hierarchies. (b) During VT, the reentrant circuit was around the Purkinje fiber network, which might be connected by the tiny FT as a slow conduction zone (red lines and arrows). To note, the left posterior fascicle (P2) was a bystander of the reentrant circuit. (c) During VT in rare cases, the slow conduction zone was from a longer FT connecting the Purkinje network and the papillary muscles (red lines and arrows). (d) The possible anatomical basis of idiopathic left fascicular VT in (b) (e) The possible anatomical basis of idiopathic left fascicular VT in (c) LPF, left posterior fascicle; LAF, left anterior fascicle; LLPF, lower or basal hierarchy Purkinje fibers; PM, papillary muscle.

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