Racker D K
Department of Medicine, Cardiology and The Feinberg Cardiovascular Research Institute, Northwestern University Medical School, Chicago, IL 60611, USA.
Anat Rec. 1999 Sep 1;256(1):49-63. doi: 10.1002/(SICI)1097-0185(19990901)256:1<49::AID-AR7>3.0.CO;2-L.
There is little detailed knowledge of the architecture of the AV junction region, the cytoarchitecture of the AV node or of its atrial connections. In the present study, the gross anatomy and topography of intracardiac structures in 21 adult canine hearts were photographically compared in whole and dissected hearts and tissue blocks and serial histologic sections made in three orthogonal planes. There are seven major new findings: 1) A coronary sinus fossa exists at the crux of the heart. It separates the right medial atrial wall (MAW) superoposterior region from the left atrium, its floor is the coronary sinus, and it carries the medial atrionodal bundle and proximal AV bundle on its right wall. 2) The posterior MAW forms two isolated bridges of myocardium as it surrounds the coronary sinus ostium, is isolated from the sinus venarum with crista terminalis and interatrial septum-by the floor of the inferior vena cava, and the narrow bridges link the posterior atrial wall to the mid MAW. 3) The tendon of Todaro has both epicardial and endocardial exposures, terminates in the superoposterior MAW and its medial aspect is adjacent sequentially to the medial atrionodal bundle and proximal AV bundle. 4) Only ordinary myocardium contacts the anulus fibrosus. 5) The ventricular septum's shoulder is humped shape posteriorly, is completely overlaid by anular myocardium and the medial leaflet and is joined by struts of papillary muscle. 6) The membranous septum joins the anterior ventricular septum to the crista supraventricularis, forms part of the posterior noncoronary and right aortic valve sinus walls and encases the right bundle branch. 7) The specialized conduction tissues, the superior, medial and lateral atrionodal bundles, the proximal AV bundle, AV node, distal AV bundle and right bundle branch are subjacent to MAW epicardium outside the right atrium, share regular intracardiac relationships with topographic landmarks and the medial atrionodal bundle, terminal superior atrionodal bundle, the proximal AV bundle and AV node are aligned to the medial leg of Koch's triangle. Thus, atrial myocardium of the AV junction region is that of the MAW. The floor of the inferior vena cava forms a natural barrier to impulse transmission along the full extent of the posterior MAW. The specialized tissues are outside of the MAW. Anatomic landmarks form reliable topographic landmarks for the specialized AV junction region tissues. A knowledge of the association of the specialized conduction tissues with specific regions of the MAW is useful in localizing the tissues and along with the coronary sinus fossa provides several extracardiac approaches.
关于房室交界区的结构、房室结的细胞结构或其与心房的连接，目前所知甚少。在本研究中，对21颗成年犬心脏内心脏结构的大体解剖和局部解剖进行了整体及解剖后的心脏、组织块以及在三个相互垂直平面制作的连续组织学切片的摄影比较。有七个主要的新发现：1）在心脏的十字交叉处存在一个冠状窦窝。它将右心房内侧壁（MAW）的后上区域与左心房分隔开，其底部是冠状窦，并且在其右壁上有内侧房室束和近端房室束。2）后MAW在围绕冠状窦口时形成两个孤立的心肌桥，通过下腔静脉的底部与界嵴和房间隔将其与腔静脉窦隔开，并且这些狭窄的桥将后心房壁与MAW中部相连。3）托达罗腱既有心外膜暴露又有心内膜暴露，终止于后上MAW，其内侧依次与内侧房室束和近端房室束相邻。4）只有普通心肌与纤维环接触。5）室间隔的肩部在后方呈驼峰状，完全被纤维环心肌和内侧瓣覆盖，并由乳头肌支柱相连。6）膜性间隔将前室间隔与室上嵴相连，形成后无冠瓣和右主动脉瓣窦壁的一部分，并包绕右束支。7）特殊传导组织，即上、中、外侧房室束、近端房室束、房室结、远端房室束和右束支，位于右心房外的MAW心外膜下方，与局部解剖标志和内侧房室束具有规则的心脏内关系，并且上房室束终末部、近端房室束和房室结与科赫三角的内侧边对齐。因此，房室交界区的心房心肌是MAW的心肌。下腔静脉的底部形成了沿后MAW全长的冲动传导的天然屏障。特殊组织位于MAW之外。解剖标志为特殊的房室交界区组织形成可靠的局部解剖标志。了解特殊传导组织与MAW特定区域的关联有助于定位这些组织，并且与冠状窦窝一起提供了几种心外途径。
