Anatomical configuration of the His bundle and bundle branches in the human heart.

Abstract

The relationships among the His bundle, the origin of both bundle branches, and the interventricular (IV) septum were examined histologically in 32 human hearts, and the entire bundle branch systems were delineated in 13 of these. The His bundle in five hearts traversed the right IV septal crest, and the LBB origin was a very narrow stem (maximum 1.5 mm in cross-section) crossing from right to left through the inferior margin of the membranous septum. Proximal LBB anatomy was extremely variable, demonstrating multiple fiber groups which fanned out over the entire left septal surface. The LBB did not divide into two discrete divisions without multiple interconnections. The RBB formed an obtuse angle with the His bundle in 27 of 32 hearts. In those five hearts with "right-sided His bundles," the right bundle branch was a direct continuation. The clinical, electrophysiologic, and electrocardiographic implications of these anatomical observations are discussed.

The relationship between electrical axis by 12-lead electrocardiogram and anatomical axis of the heart by cardiac magnetic resonance in healthy subjects

“…An explanation for the great variability in the electrical axis in relation to the anatomical axis of the heart may be a great interindividual variability in how the Purkinje network of the heart is organized. It has been shown that there is a considerable variation in the architecture of the distal conduction system (27). Furthermore, the stronger age-dependence of electrical axis than of anatomical axis found in the frontal plane in present study, might partly be explained by increased fibrosis and fatty infiltration in the conduction system with increased age (28).…”

Crib death: further support for the concept of fatal cardiac electrical instability as the final common pathway

“…Massing and James [60] found this position in 62.5% of normal human hearts of various age. Left sided His bundle has been described in association with sudden death in previously healthy people [72,82] and in asthmatics [83].…”

Modeling of realistic heart electrical excitation based on DTI scans and modi ed reaction diffusion equation

“…The RV completes its depolarization later than the LV. However, these isochrones may not be identical, as the conduction systems of different human hearts do not have identical structures [8]. using the proposed conduction system and the modified RDE.…”

“…To simulate heart electrical activation, both structures must be identified, especially the conduction system, as it initiates the activation. The most common reference models used to identify the ventricular conduction system of the heart are those described by Tawara [7], Massing et al [8], and Durrer et al [9]. Modeling of the ventricular conduction systems involves either assigning the early activation sites according to the measurements of Durrer et al [10][11][12][13] or building a network according to the heart anatomical structure and activation isochrones [14][15][16][17].…”

“…Modeling of the ventricular conduction systems involves either assigning the early activation sites according to the measurements of Durrer et al [10][11][12][13] or building a network according to the heart anatomical structure and activation isochrones [14][15][16][17]. The conduction system of the ventricles varies considerably from heart to heart [8], which makes identifying the correct structure of the conduction system model subject to trial and error, as a small variation in conduction sites will produce a large variation in activation results. Other groups of models do not model any conduction system, as they use experimental pacing sites in their models [18][19][20].…”