1. Membranous septum and the proximal left bundle branch.
Membranous septum and the proximal left bundle branch. The left panel shows a virtual dissection reconstructed similar to the echocardiographic parasternal long-axis image. The white star indicates the membranous septum. With known knowledge (right panel) concerning the location of the left bundle branch (RED) ramifying from the branching portion of the bundle of His24 26 in the antero-inferior margin of the membranous septum (black-dotted area, superimposed on the original image of Tawara26), such combined images help the interventionists appreciate the danger zone during transcatheter aortic valve implantation. Note that, when described in attitudinally appropriate terminology, the so-called ‘anterior’ and ‘posterior’ fascicles of the left bundle are more appropriate referred to as the superior and inferior fascicles respectively.27 R, right coronary aortic sinus; N, non-coronary aortic sinus.
Justin T Tretter et al. Open Heart 2019;6:e000972
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