Three‐dimensional visualization of the bovine cardiac conduction system and surrounding structures compared to the arrangements in the human heart

xloma.fota13 shared this article with you from Inoreader Three‐dimensional visualization of the bovine cardiac conduction system and surrounding structures compared to the arrangements in the human heart Via Journal of Anatomy We have now been able to show the three‐dimensional relations of the inferior pyramidal space in bovine hearts, revealing its important topographical relations with the main cardiac bone and non‐branching part of the conduction axis Abstract In the human heart, the atrioventricular node is located toward the apex of the triangle of Koch, which is also at the apex of the inferior pyramidal space. It is adjacent to the atrioventricular portion of the membranous septum, through which it penetrates to become the atrioventricular bundle. Subsequent to its penetration, the conduction axis is located on the crest of the ventricular septum, sandwiched between the muscular septum and ventricular component of the membranous septum, where it gives rise to the ramifications of the left bundle branch. In contrast, the bovine conduction axis has a long non‐branching component, which penetrates into a thick muscular atrioventricular septum having skirted the main cardiac bone and the rightward half of the non‐coronary sinus of the aortic root. It commonly gives rise to both right and left bundle branches within the muscular ventricular septum. Unlike the situation in man, the left bundle branch is long and thin before it branche s into its fascicles. These differences from the human heart, however, have yet to be shown in three‐dimensions relative to the surrounding structures. We have now achieved this goal by injecting contrast material into the insulating sheaths that surround the conduction network, evaluating the results by subsequent computed tomography. The fibrous atrioventricular membranous septum of the human heart is replaced in the ox by the main cardiac bone and the muscular atrioventricular septum. The apex of the inferior pyramidal space, which in the bovine, as in the human, is related to the atrioventricular node, is placed inferiorly relative to the left ventricular outflow tract. The bovine atrioventricular conduction axis, therefore, originates from a node itself located inferiorly compared to the human arrangement. The axis must then skirt the non‐coronary sinus of the aortic root prior to penetrating the thicker muscular ventricular septum, thus accounting for its long non‐branch ing course. We envisage that our findings will further enhance comparative anatomical research. View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.