房室结后延伸部形态学特征及与折返性心动过速的关系

Study on the relationship between histology of atrioventricular nodal posterior extensions and AVNRT

目的:研究人房室结双径路,尤其是慢径的解剖学基础。方法:(1)取17例尸检心脏包括房室结在内的房室交界区的组织固定、脱水、包埋后切片,HE和Masson染色,光镜观察。(2)由冠状窦口向房室结方向在心内膜下注射墨汁0.5 ml,24h后光镜观察墨汁走向。结果:17例标本均可发现房室结,房室结前向形成房室束(His束),发现47％(8例)有明确向后延伸-左后延伸和右后延伸,35％(6例)仅有右后延伸,1例发现仅有左后延伸,2例未发现有向后延伸。向后延伸由房室结自然延伸而成,其有房室结自然延伸而成,左后延伸朝左行向房间隔,右后延伸行向右,与三尖瓣隔瓣近乎平行,纤维可达冠状窦口附近。结论:房室结后延伸部可能为慢径路,作为房室结折返性心动过速(AVNRT)的射频消融慢径的解剖学基础.

Objective: To investigate the characteristcs of histology of atrioventricular junction (AVJ) and seek the histological substrate of dual atrioventricular nodal pathways (DAVNP).Methods: The specimens including atrioventricular node (AVN) were fixed with formalin. Tissue blocks were cut serially in three planes: sagittal plane, coronal plane and frontal plane. Sections were stained either by Masson trichrome procedure or by hematoxylin and eosin. Results: A distinct compact node was found in each of the 17 hearts. 8 hearts had posterior extensions both on the right side and on left side.6 hearts only had a rightward postenor extension. One heart only had a leftward posterior extension, whereas two hearts had no posterior extension. Furthermore, the rightward extension continued to the Ievel of the coronary sinus ostium. Conclusion: The human compact node contains rightward and leftward posterior extension, with the right extension close to tricuspid annulus and coronary sinus ostium. It is speculated that the superficial strata might be the fast pathways and the extensions might be the slow pathways.