冠状窦口和周围心肌组织的形态学研究

目的通过观察冠状窦口(CSO)及其周围心肌组织的形态学特征,探讨其在射频消融房内折返性心律失常和房室结折返性心动过速(AVNRT)方面的功能意义。方法正常成人心脏15例,其中7例用于大体解剖观察,7例用于光镜观察,1例用于电镜观察。组织连续切片用HE和Mallory染色。光镜对CSO及其周围心肌组织的形态、排列方式和染色深浅进行细致观察,透射电镜观察证实光镜所见细胞特征。结果CSO及窦的大部分均有房肌包绕,CSO处肌纤维向后与界嵴下延伸和右房瓣上肌环的心肌有联系,向前也与房室结(AVN)有联系。CSO上前壁和下前壁均可见P细胞,T细胞以下壁多见,浦肯野细胞以上壁多见。在CSO至AVN的路径中可见主要由T细胞构成的纤维束,该部位可被分为两部分:靠近CSO的一段肌纤维称为右房结束(RANB);靠近AVN的一段肌纤维称结后延伸(PNE)。另外,还在CSO周围心肌中尤其是后壁的脂肪组织中见到大量神经纤维、神经元或神经节。结论①CSO附近心肌参与了房室结双径路(DAVNP)中慢径的组成;②CSO附近心肌参与了房内折返性心律失常和AVNRT环路的形成;③CSO可能是一个重要的结外起搏点。

The morphologic study of coronary sinus orifice and its peripheral myocardium

Objective To observe the cellular morphologic features of coronary sinus orifice(CSO) and its peripheral myocardium and discuss its functional significance in radiofrequency ablation atrial reentrant arrhythmias and AVNRT. Methods A total of 7 out of 15 cases were observed by means of autopsy, and serial sections of 7 cases of adult hearts in sagittal plane were stained with HE and Mallory staining. The cellular features of different muscular fibers and their arrangement were observed under light microscope; one case was studied under electron microscope. Results CSO and the majority of coronary sinus were encompassed by atrial myocardium; CSO fibers toward posterior was connected with extension of terminal crest (CT); and supravalvular muscular ring of right atrium(RAMR) and that toward anterior was connected with AVN. P cells were seen in superior-anterior and inferior-anterior wall of CSO. A lot of T cells were discovered on the inferior wall of CSO. Purkinje cells were mainly found in the superior wall of CSO. The muscular fibers from CSO to AVN were composed of T cells and dissected into two parts: the first one was called right atrial nodular bundle and the second one posterior node extension which was identical with the ablation target of slow pathway. In addition, lots of nerve fibers were seen in myocardium of CSO adjacency particularly in the tissue of the posterior wall of CSO. Conclusion Myocardium of CSO adjacency may belong to slow pathway of DAVNP. The myocardium of CSO adjacency participates in the formation of circular pathway in atrial reentrant arrhythmias and AVNRT. It is possible that CSO is an important latent pacing maker.