Bharati S, Lev M
Heart Institute for Children of Christ Hospital and Medical Center, Palos Heights, Illinois 60463.
Pacing Clin Electrophysiol. 1989 Jan;12(1 Pt 2):159-69. doi: 10.1111/j.1540-8159.1989.tb02643.x.
The pathology of the heart, including that of the conduction system, after various catheter techniques used to ablate the various parts of the conduction system and the myocardium, were examined histologically by serial sections. The experiments were conducted on canines. The conduction system studies included the approaches to the AV node, the AV node, the AV bundle and bundle branches, as well as, the central fibrous body, the tricuspid, mitral and aortic valves. The methods of ablation were DC shock, laser and radio frequency energy. Production of the complete AV block clinically was associated with fibrosis with or without cartilage formation of the approaches to the AV node, the AV node, the bundle and the beginning of the bundle branches in most cases. On the other hand, creation of first degree AV block was associated with fibrotic changes in the approaches to the AV node and the AV node, and second degree block with more changes to the AV node. Coronary sinus ablation resulted in necrosis and fibrosis of the coronary sinus wall with occasional thrombosis of the coronary sinus. The adjacent atrial and/or the ventricular myocardium also showed fibrosis. Likewise, ventricular septal ablation was associated with focal areas of fibrosis of the myocardium. The conduction system was intact in both of the above experiments. In one human where complete AV block was created to manage intractable atrial fibrillation, the AV node, the bundle, and the bundle branches were fibrosed. In addition, there was a fibrosed atrio-Hisian connection and the patient died suddenly six weeks after the ablative procedure. The surrounding structures close to the vicinity of the conduction system, such as the aortic, tricuspid, mitral valve, the central fibrous body, and the summit ventricular septum are involved to a varying degree. In summary, (1) Whatever the method of ablation may be, the end result was fibrosis with or without cartilage formation of the ablative area. (2) Congenital anomalies of the conduction system such as an atrio-Hisian connection may remain elusive for ablative methods, and arrhythmias may persist and may cause sudden death in some cases.
通过连续切片组织学检查，观察了在使用各种导管技术消融传导系统和心肌的各个部位后心脏的病理情况，包括传导系统的病理情况。实验在犬类动物身上进行。传导系统研究包括到达房室结、房室结、房室束和束支的路径，以及中心纤维体、三尖瓣、二尖瓣和主动脉瓣。消融方法包括直流电休克、激光和射频能量。临床上完全性房室传导阻滞的产生在大多数情况下与房室结、房室结、束支及束支起始部的纤维化有关，伴有或不伴有软骨形成。另一方面，一度房室传导阻滞的产生与房室结及房室结路径的纤维化改变有关，二度房室传导阻滞则与房室结的更多改变有关。冠状窦消融导致冠状窦壁坏死和纤维化，冠状窦偶尔会出现血栓形成。相邻的心房和/或心室心肌也表现出纤维化。同样，室间隔消融与心肌的局灶性纤维化区域有关。上述两个实验中的传导系统均保持完整。在一名通过制造完全性房室传导阻滞来治疗顽固性心房颤动的患者中，房室结、束支和束支均发生纤维化。此外，存在纤维化的心房 - 希氏束连接，患者在消融手术后六周突然死亡。靠近传导系统附近的周围结构，如主动脉瓣、三尖瓣、二尖瓣、中心纤维体和室间隔顶部，均有不同程度的累及。总之，（1）无论采用何种消融方法，最终结果都是消融区域出现纤维化，伴有或不伴有软骨形成。（2）传导系统的先天性异常，如心房 - 希氏束连接，对于消融方法可能仍然难以察觉，心律失常可能持续存在，并且在某些情况下可能导致猝死。
