Delay in or block of conduction through the middle (septal) fibers of the left bundle branch: Can it be recognized on the body surface electrocardiogram?

摘要

Tawara1 published his remarkable monograph describing the conduction system of the mammalian heart 106 years ago. His reconstructions of the ramifications of the left bundle branch (LBB) over the endocardial surface of the left ventricle in the human heart demonstrated how variable this could be, but there were always components inserting into the left surface of the interventricular septum (TVS). In some cases, these took the form of a diffuse net, but in others, in addition to more commonly seen bundles of fibers (termed fascicles) travelling to the left anterior and left posterior endocardial myocardium, a separate bundle of fibers originating in the main left bundle branch was the source of these septal fibers.