目的　探讨划分心传导系统 (CCS)形态变异与发育异常 (畸形 )的界线。　方法　用我们建立的CCS检查法 ,即窦房结和房室结沿其长轴切 1～ 2块 ,房室束沿长轴垂直切 2～ 4块 ,连续切片 ,间断取片 ,每例共取 30片。对 886例 (非心源性死亡 737例 ,心源性猝死 149例 )人CCS进行组织学观察 ,并对两组进行CCS形态、死因分析比较。　结果　 1 人CCS具有大小、位置及形态的先天性变异 ;2 也有增龄性变化的后天性变异 ;3 死因不明的心源性猝死者中CCS见到有成年人胎儿型房室结、房室结全部移位至房室束穿部、房室束穿部完全分成 3束以上、房室束分叉部房室结化及移位至三尖瓣根部等 ,这些改变不应认为是正常变异 ,因为它们都可能有病理学意义。　结论　房室束分叉部向室间隔膜部内移位、偏位于室间隔左侧、向室间隔左下侧移位 ,以及不足 1 2房室结移位至中心纤维体内 (房室束穿部 ) ,心肌束移位于房室束或左束支内等应属CCS变异 ,不是畸形。 Objective To explore the boundary of delineation of morphological and developmental abnormalities (deformities) in cardiac conduction system (CCS). Methods CCS with our method established that the sinoatrial node and atrioventricular node along its long axis cut 1 to 2 blocks along the long axis of the vertical cut 2 to 4, Take 30 pieces. The CCS of 886 cases (737 cases of non-cardiac death and 149 cases of sudden cardiac death) were observed by histology. The CCS morbidity and mortality were compared between the two groups. Results 1 CCS had the same size, location and shape of congenital variation; 2 also had age-related changes in acquired mutations; 3 death of unknown cause of sudden cardiac death in CCS to see adult fetal atrioventricular node, atrioventricular Knot all shifted to the atrioventricular bundle Department, atrioventricular Department of the beam is completely divided into three or more, atrioventricular bundle bifurcation of the junction and the transfer to the tricuspid root and so on, these changes should not be considered normal mutation , Because they all may have pathological significance. Conclusions The bifurcation of the atrioventricular bundle shifts to the interventricular septum and is displaced to the left of the interventricular septum and translocates to the left inferior compartment of the interventricular septum. In addition, less than 12 atrioventricular nodes are translocated to the central fibrous body (atrioventricular bundle) , Myocardial bundle in the atrioventricular bundle or left bundle branch should belong to CCS mutation, not deformity.