正常犬左束支射频消融的实验研究

射频消融 (RFCA)左束支可以治愈少数束支折返性室性心动过速 ,并可能作为减轻肥厚型梗阻性心肌病左室流出道压力阶差的一种方法。为探讨射频导管消融左束支的方法及其可行性、安全性。对 15条犬心左束支施行RFCA ,9条犬成功消融左束支、5条犬发生完全性房室阻滞 (AVB)、1条犬造成右束支阻滞。研究发现 9条消融成功犬心损伤灶位于右冠瓣与无冠瓣交界区下方 1～ 2cm ,Ⅲ度AVB者位于右冠瓣和无冠瓣的交界处 ,右束支者消融靶点位于主动脉瓣无冠瓣和右冠瓣交界处靠前处。研究还发现仅以标测到的左束支电位难以准确消融左束支 ,而单纯以X线影像定位就能成功阻断左束支。左束支阻断后 ,可以造成室间隔的异常运动。     

射频导管消融阻断左束支的实验研究

为探讨射频导管消融（ＲＦＣＡ）阻断左束支的方法及其可行性、安全性，对１１只山羊心脏的左束支施行ＲＦＣＡ。每只山羊放电８．８±４．１次，每次放电功率３２．０５±６．６２Ｗ、放电时间５９．１８±２８．６５ｓ、放电消融面积为４１．０±４０．４ｍｍ２，总放电时间４４４．１８±３０７．２４ｓ。放电消融的靶点位于主动脉瓣下方、室间隔后下部。有９只山羊的左束支被成功地完全阻断，未发生完全性房室阻滞或右束支阻滞。结果提示采用ＲＦＣＡ可以安全地阻断左束支     

正常犬左束支电位标测与走行的关系及其试消蚀

射频消蚀左束支可以治愈少数束支折返性室速和减轻肥厚性梗阻型心肌病的左室流出道压力阶差。本实验目的在于探讨左束支电位标测与解剖走行的关系。结果发现仅以标测到的左束支电位难以准确消蚀左束支，必须结合影像定位才能成功阻断左束支、有效预防完全性房室传导阻滞的发生。     

左束支传导阻滞犬模型行左束支区域起搏的实验研究

目的建立左束支传导阻滞(LBBB)犬模型, 探讨左束支区域起搏(LBBAP)纠正LBBB的可行性及有效性。方法研究选取6只比格犬, 雌雄各半, 体重(17.7±1.4)kg, 在X线影像及三维模型指导下, 应用压力消融导管经主动脉逆行途径标测并消融左束支。成功建立LBBB模型后, 在X线影像指导下进行LBBAP。分析LBBAP的起搏参数和左心室达峰时间, 并比较LBBAP前后的QRS波形态和时限。结果 6只犬均成功建立LBBB模型, 其中5只犬成功进行LBBAP, 1只犬因心室导线无法旋入室间隔致导线植入失败。LBBAP起搏阈值感知参数良好, LBBAP的左心室达峰时间明显缩短(48.2±2.5)ms, LBBAP前后QRS时限变化差异有统计学意义[(118.4±3.2)ms对(57.6±3.2)ms, P<0.001)]。结论成功建立LBBB犬模型。LBBAP能够有效纠正LBBB, 具有较高的可行性。     

不同浓度乙酰甲胆碱介导犬心房颤动的电生理标测和射频消融

目的 研究静滴不同浓度乙酰甲胆碱（Mach）诱发的犬心房颤动（AF）模型,观察电生理标测及不同部位射频消融的结果。方法 实验选用6只犬。于低浓度、中等浓度及高浓度Mach静滴时诱发AF并行电生理标测。低浓度时3只犬先作上腔静脉至下腔静脉的右房后侧壁线性消融,再作右房前侧壁的线性消融。3只犬仅作右房前侧壁的线性消融。中等浓度时作Bachmann’s束（BB）的射频消融。高浓度时选择电生理标测到的规则周期波部位作局部射频消融。结果 低浓度Mach［（1.04±0.37）μg/(kg·min)］介导的AF,右房小梁部心内电图较间隔部及左房相对紊乱且周长较短。对该部位作射频消融可使AF不被诱发,但提高Mach浓度后即不再有效。中等浓度Mach［（2.70±0.49）μg/(kg·min)］介导的AF,左房及间隔部心内电图较小梁部相对紊乱且周长较短。BB消融后5只犬AF终止,4只不再被诱发,但倍增Mach浓度后,该部位的消融亦不再有效。高浓度Mach ［（5.42±0.97）μg/(kg·min)］介导的AF,2例分别于BB左侧及左心耳基底部记录到局部规则周期波,其中1例行局部射频消融后,AF终止,但仍可再诱发。结论 低浓度Mach介导的AF,右房小梁部是其发生的关键部位。中等浓度Mach介导的AF,房间隔或左房是其发生和维持的关键部位。高浓度Mach介导的AF有局灶起源部位。不同浓度Mach介导AF的有效消融区域不同。     

三维标测指导下的阵发性室上性心动过速射频消融

目的探讨与常规标测相比。三维标测指导下的阵发性室上性心动过速射频消融的可行性、安全性与优势。方法回顾性分析2013年1月至8月,在宁波市第一医院行射频消融术的阵发性室上性心动过速的患者114例,按照标测方法分为三维标测组与常规标测组,比较两组间的射频消融成功率、并发症发生率、手术时间、x线曝光时间与x线曝光量。结果两组所有手术均获得即刻成功,均无并发症发生。两组的手术时间比较,差异无统计学意义[（77．6±28．1）min vs.（70．4±23．2）min,P〉0．05]。三维标测组的x线曝光时间与x线曝光量均显著低于常规标测组（中位数：4．2minvs．15．4min,P〈0．01;中位数：11．0mGyvs76．7mGy,P〈0．01）,差异有统计学意义。结论阵发性室上性心动过速的射频消融术与常规标测相比,采用三维标测指导具有相同的成功率与安全性,并不延长手术时间,且能显著减少x线曝光时间与x线曝光量。     

左束支区域起搏应用于合并左束支阻滞心力衰竭患者的研究进展

生理性起搏如希氏束起搏和左束支区域起搏能明显改善心脏电机械收缩同步性,而左束支区域起搏相较于希氏束起搏植入成功率高,起搏阈值低而稳定,且并发症发生率较低。左束支区域起搏用于合并左束支阻滞的慢性心力衰竭患者的可行性、安全性和有效性已得到初步证实,逐渐成为研究的热点。现就左束支区域起搏在合并左束支阻滞的心力衰竭患者中的相关研究及进展做一综述。     

左束支阻滞型特发性室性心动过速的心电图特征对射频消融成功的影响初探

对心电图呈左束支阻滞型的特发性室性心动过速 (简称室速 )的临床特点和心电图进行分析 ,以了解哪些因素可以预测此类患者从右室流出道行射频消融的成功率。对 2 6例特发性室速的患者进行电生理检查和射频消融手术 ,全部患者室速时的心电图呈左束支阻滞。结果 :2 6例中 ,2 2例于右室流出道进行了成功消融 ,成功和未成功消融的患者临床特征和电生理无明显区别 ,成功消融的患者中胸前V1 导联心电图呈rS型 (1 2例 )和QS型 (1 0例 ) ,而 4例未成功者 ,V1 导联均呈rS型 ,其中 2例经主动脉于左冠状窦消融成功。在成功与未成功消融患者中 ,V1 导联有无R波无明显区别 ,但V1 导联无R波预示室速可以从右室流出道成功消融 ,成功消融的室速患者胸前导联的平均移行区在V4导联 ,而未成功患者胸前导联的移行区在V3 或V2 导联。结论 :某些心电图呈左束支阻滞 ,且额面电轴正常或右偏的特发性室速患者不能成功从右室流出道消融 ,V1 导联有r波且移行区在V3 导联或之前者提示此类心电图特征的室速可能非起源于右室流出道 ,部分可能起源于左室流出道     

Radiofrequency Catheter Ablation of the Left Bundle Branch in a Canine Model

Left Bundle Branch Ablation. Introduction: Transcatheter ablation of the left bundle branch may be considered for management of selected macroreentrant ventricular tachycardias. Left bundle ablation can also change the sequence of left ventricular contraction and may simulate pacing in hypertrophic obstructive cardiomyopathy. The purpose of this study was to determine electrophysiologic and anatomic parameters for successful selective transcatheter left bundle ablation in a canine model. Methods and Results: A catheter was advanced to the left ventricular apex and the tip deflected toward the septum, until a discrete left bundle potential (LBP) was found. Radiofrequency (RF) energy was then applied until left bundle branch block or complete AV block occurred. In 29 (85%) dogs, an LBP (mean LBP-V 16 ± 3 msec; range 10 to 20 msec) was identified resulting in successful left bundle ablation. In 5 (15%) dogs, a similar potential (mean potential-V 28 ± 4 msec; P = 0.001 vs LBP-V) was identified, but RF energy application produced complete AV block. The A:V electrogram ratio at the successful LBP ablation site was < 1:10 in all 29 dogs successfully ablated, but only 2 (40%) of 5 dogs in the unsuccessful group (P = 0.0017). In 4 successfully ablated dogs, the right bundle potential was mapped and complete AV block was created by RF energy application, confirming that the left bundle was completely ablated. In 9 dogs, the left bundle and AV junction were sequentially ablated with 1 lesion at each site. Postmortem examination showed 2 discrete lesions 1.2 ± 0.7 cm apart. Conclusions: Selective transcatheter left bundle ablation was successfully guided by the LBP. The distance between the AV junction and the main left bundle was 1.2 cm in this canine model. An A:V ratio < 1:10 and an LBP-V time < 20 msec appear to minimize the risk of AV block. Prudent use of similar techniques may cure macroreentrant ventricular tachycardias and reduce the need for permanent pacing in hypertrophic obstructive cardiomyopathy.     

Catheter Ablation of the Left Bundle Branch for the Treatment of Sustained Bundle Branch Reentrant Ventricular Tachycardia

Sustained Bundle Branch Reentrant VT. Radiofrequency catheter ablation of the left bundle branch (LBB) was attempted in a patient with sustained bundle branch reentry. During sinus rhythm, the QRS had a complete LBB block pattern, and the LBB was activated retrogradely (transseptal). Ablation of the LBB eliminated inducibility of the tachycardia, while the QRS complex and the duration of the HV interval (70 msec) remained unchanged. Successful ablation of the LBB eliminated bundle branch reentry and yet maintained the anterograde conduction properties of the His-Purkinje system, obviating implantation of a permanent pacemaker.     

希氏束旁旁路的射频消融

目的探讨希氏束旁旁路射频的可行性和安全性。方法10例心内电生理检查确诊为希氏束旁旁路患者,其中显性旁路3例,隐性旁路7例。窦律下采用能量滴定法温控消融,从小功率(10W)短时间(5s)开始。结果10例患者除2例担心手术风险拒绝消融治疗外,余8例全部行射频消融治疗并获得成功。温度55~60℃,功率平均26.7±11.9W,消融时间60s,重复诱发无心动过速,术后随访3~6月无复发。结论窦律下消融希氏束旁旁路,是安全有效的。但应从小功率短时间开始,严密心电监护下进行。     

Incessant Interfascicular Reentrant Ventricular Tachycardia as a Result of Catheter Ablation of the Right Bundle Branch: Case Report and Review of the Literature

A 72-year-old woman developed incessant interfascicular (IF) ventricular tachycardia immediately after successful right bundle branch (RBB) catheter ablation for the treatment of sustained bundle branch reentrant tachycardia. Catheter ablation of the left bundle branch and the left anterior fascicle was successful in eliminating the tachycardia (in 2 different sessions). This report discusses the direct link between the creation of an RBB block and the development of IF tachycardia, in our case, and in prior cases of IF reentry reported in the literature.     

利用组织多普勒评价左束支阻滞患者心室内不同步

利用组织多普勒测量不同步指数评价左束支阻滞 (LBBB)患者心室内不同步 ,对 15例LBBB患者 (LBBB组 )和 15例正常人 (对照组 )左心室各壁基底、中间、心尖段 ,获取组织多普勒速度曲线 ,分别测量QRS波起点到S波起点的时间 (Q Sb) ,计算心室内同步性指数 (TSI)和各室壁壁内的同步性指数 (RSI)。结果 :LBBB组患者各壁Q Sb延长 ,以室间隔、前壁、下后壁显著 ;TSI和左室室间隔的RSI较对照组明显增高 (分别为 30 .86± 9.78msvs 14 .81± 6 .89ms;2 7.13± 16 .82msvs 12 .19± 10 .70ms ,P均 <0 .0 1)。结论 :LBBB时左室激动顺序异常 ,左室各壁各节段出现不同程度的收缩延迟 ,心室内不同步明显 ;同一室壁内的不同步 ,以室间隔最显著。     

Cure of Interfascicular Reentrant Ventricular Tachycardia by Ablation of the Anterior Fascicle of the Left Bundle Branch

Ablation of Interfascicular Reentrant Tachycardia. Introduction: Fascicular reentrant ventricular tachycardia (VT) using the anterior fascicle of the left bundle anterogradely is rare and may produce identical QRS morphology during sinus rhythm and VT. Catheter ablation of this type of VT has not been described in detail.
Methods and Results: In a postinfarct patient with dilated left ventricle and recurrent VT (showing a QRS configuration of right bundle branch, left posterior fascicular block), endocardial recordings from the His-Purkinje system showed that VT was due to interfascicular reentry. Induction of VT occurred after progressive retrograde conduction delay on increasing the prematurity of the extrastimulus. Anterograde conduction occurred exclusively over the left anterior fascicle, which caused identical QRS morphology during sinus rhythm and VT. During VT, the left posterior fascicle was used retrogradely. The usual target for bundle branch reentry ablation, the right bundle, did not participate in the reentrant circuit. While performing left ventricular endocardial mapping, VT was interrupted when positioning the catheter on the left anterior fascicle, and "reversed" nonsustained bundle branch reentry occurred with anterograde conduction over the posterior fascicle and retrograde conduction over the anterior fascicle. Ablation of conduction in the anterior fascicle led to cure of the VT.
Conclusion: Interfascicular reentrant VT with right bundle branch block, right-axis QRS configuration can be cured by catheter ablation of anterior fascicle conduction.