中文摘要：

目的本研究旨在探讨左后分支阻滞能否作为左后分支室性心动过速（室速）长期消融成功的预测因子。方法从2010年1月至2012年12月，南京医科大学第一附属医院心内科的67例左后分支室速患者在三维标测指导下消融，心房／心室短阵快速（Burst）与程序刺激诱发室速。室速时激动标测寻找最早P电位，即消融靶点；若室速不能诱发，行起搏标测寻找消融靶点。消融采用温控模式。消融后静脉滴注异丙肾上腺素与心房/心室Burst与程序刺激不能诱发视为消融成功。根据消融后有无左后分支阻滞，将患者分成左后分支阻滞组（A组）和左后分支未阻滞组（B组），并进行长期随访。结果67例患者平均年龄（30．1±12．6）岁（男53例），2例未诱发出室速，1例因靠近希氏束未消融。61例患者完成室速激动标测寻找到最早P电位消融，3例起搏标测找到靶点消融。消融后静脉滴注异丙肾上腺素与心房／心室刺激均未诱发出室速。A组46例，B组18例。术后平均随访（55．8±10．4）个月。53例患者未复发，长期成功率为82．8％（53／64）；11例患者复发，其中A组8／46例，B组3／18例（P=0．94）。消融术后至复发时间为1．4—54．9（9．2±16．1）个月。11例复发患者均再次成功消融。首次消融失败1例患者，再次消融成功。所有患者术中、术后均没有出现并发症。结论激动标测寻找最早P电位指导左后分支室速消融治疗安全有效，近5年随访成功率近83％。左后分支阻滞不能预测左后分支室速的消融成功。

英文摘要：

Objective Until now, whether left posterior fascicular block （LPFB） could predict the success of ablation for fascieular ventricular tachycardia （VT） is ongoing controversy. In this study, we investigated whether LPFB could be as the predictor of left posterior fascicle VT（LPF-VT） long term success after ablation. Methods From January 2010 to December 2012, consecutive patients （n = 67） with LPF-VT underwent mapping and ablation by using three dimension mapping and ablation were enrolled in department of cardiology the First Affiliated Hospital of Nanjing Medical University.Burst and programmed stimulation at the right atrium and right ventricle apex were used for VT inducing. Activation mapping was performed to find the ablation target （earliest fascicular potential, PP ） during VT. Pace mapping was used to locate the ablation target for patients in whom VT could not be induced. Ablation was performed by delivering radiofrequency energy in temperature-control mode. According to LPFB or not, patients were assigned to LPFB group （group A） and LPF not block group （group B ）, and with long-term follow-up. Results Among 67 patients （mean age 30. 1 ± 12.6, male 53 ） with LPF-VT, VT could not be induced in two cases, failed ablation in one case. Ablation target with earliest P potential was located by activation mapping during VT in 61 patients.Ablation target was disclosed by pace mapping in 3 patients.Altogether, ablation was succeeding