家兔房室交界区及其心房传导通路的形态学研究

目的：探讨射频消融改良房室交界区的形态学基础。方法：健康成年家兔10只，分别做房室交界区的额状面、矢状面及水平面连续切片，在HE、Masson及磷钨酸苏木素染色下观察其形态学特征。结果：家兔房室结位于房室隔内中心纤维体的右侧，主要由P细胞和T细胞组成，以P细胞为主，其向后形成的延伸部同射频消融慢径的部位吻合，且细胞分布明显较房室结稀疏，内有胶原纤维分隔。同时有四条过渡细胞带分别从心房的不同部位到达房室结及后延伸部，分别称为左房结束、右房结束、后房结束及上房结束。另外，在冠状窦前壁有P细胞成团分布。结论：①房室交界区的概念应当扩大，分布范围从房室隔内中心纤维体的右侧一直向后接近冠状窦口，前部可能为快传导区，后部可能为慢传导区。②房内传导通路确有存在，并且可能参与了房内折返性心律失常的形成。③冠状窦是一个重要的结外潜在起搏点，可能与某些房性自律性心律失常的发生有关。

Morphological study of rabbit atrioventricular junction and its conductive pathways from atrium

Objective: To investigate the morphological basis of atrioventricular junctional modification using radiofrequency ablation. Methods: 10 cases of rabbit heart were studied with sections along the sagittal plane, frontal plane and horizon plane of atrioventricular junction (AVJ), and cytomorphological features were noted adopting different stain of HE, Masson and phosphotungstic acid. Results: The atrioventricular node (AVN) of rabbit located in the atrioventricular septum and the right of central fibrous body (CFB). The main cells of AVN were P cells and T cells. All specimens had posterior node extensions (PNE), the position of which was identical with the ablation target of slow pathway. There were 4 transitional cell bundles from different parts of atrium to AVN and PNE. In addition to sinus node and AVN, P cells were also found in anterior wall of coronary sinus. Conclusion: The concept of AVJ should be enlarged, from the right part of CFB extends to the coronary sinus ostium, while the anterior part may be related to fast pathway and the posterior part may be related to pathway. The intraatrial pathways were authentic exist and may be involved in the formation of atrial arrythmia. The coronary sinus was an important potential pacing maker and may be relative to some arrythmiadue to enhanced automaticity.