Radiofrequency catheter ablation of idiopathic left ventricular outflow tract tachycardia: utility of intracardiac echocardiography

INTRODUCTION: The site of origin of idiopathic ventricular tachycardia (VT) arising from the left ventricular outflow tract (LVOT) may be closely related to the aortic valve leaflets, and radiofrequency (RF) delivery potentially can damage them. Intracardiac echocardiography (ICE) can identify accurately the ablation electrode and anatomic landmarks, and contact with the endocardium can be easily assessed. The aim of this study was to define the utility and the accuracy of ICE in guiding RF ablation of idiopathic VT of the LVOT. METHODS AND RESULTS: Five consecutive patients (all men; mean age 20.4 years, range 16 to 25) symptomatic for idiopathic VT underwent RF ablation. A 9-French, in-sheath catheter with a 9-MHz ultrasound transducer was inserted through the femoral vein and positioned in the His-bundle region or right ventricular outflow tract to provide a clear view of the aortic root. Local earliest ventricular activation during tachycardia and pace mapping were used to identify the ablation site. Idiopathic VT was ablated successfully in all patients using a median of two RF pulses, delivered during tachycardia. High-resolution images of the aortic valve and ablation electrode were achievable in all cases. Direct vision of ablation electrode-endocardial contact in the outflow tract was assessed easily in all patients. CONCLUSION: Idiopathic VT of the LVOT can be treated successfully with RF ablation. ICE can accurately guide catheter ablation and identify anatomic landmarks, endocardial contact, and ablation electrode movement.     

特发性室性心动过速及室性期前收缩的射频消融治疗

目的探讨射频导管消融(radiofrequency catheter ablation,RFCA)治疗特发性室性心动过速(idiopathic ventricular tachycardia,IVT)和室性期前收缩(premature ventricualr contraction,PVC)可行性、必要性和疗效。方法回顾性分析16例IVT、PVC患者采用激动顺序标测和起搏标测法确定室性心动过速(ventricular tachycardia,VT)、PVC的起源部位并行RFCA治疗的资料。结果 3例IVT中2例起源于左室间隔部左后分支的蒲肯野系统,1例起源于右心室流出道(right ventricular outflow tract,RVOT)游离壁,同时合并另一种游离壁起源的PVC,3例消融均成功,1例复发。13例PVC中7例起源RVOT间隔部,3例起源于RVOT游离壁,1例同时存在两种形态PVC(分别起源于ROVT间隔部和游离壁),2例起源于左心室流出道,13例消融成功,1例复发。结论 RFCA治疗IVT及特定部位的PVC是安全、有效且成功率高的一种方法。     

Radiofrequency catheter ablation in recurrent ventricular tachycardia.

Catheter ablation by radiofrequency energy was carried out in 10 patients with one type of recurrent monomorphic sustained ventricular tachycardia resistant to medical antiarrhythmic management. Electrophysiological studies before ablation included activation and pace-mapping. In all patients, the origin of the tachycardia was localized in the left ventricle: in the septum in six, at the posterolateral wall in three and anterobasal in one. The earliest onset of endocardial activation preceding the QRS complex during ventricular tachycardia ranged between -45 and -90 ms. Transcatheter ablation was performed with a bipolar or quadripolar catheter using a radiofrequency generator (HAT 100, Osypka). No complications occurred during the ablation procedure. Thereafter, in all patients, the clinical tachycardia was no longer inducible by programmed stimulation. During a follow-up period of 22 to 32 months including eight patients, the tachycardia recurred in two; one of these patients subsequently died suddenly. A third patient had one episode of a new type of sustained ventricular tachycardia some hours after catheter ablation. In the remaining patients, there was no recurrence of symptomatic tachycardia under maintenance of the antiarrhythmic management which, prior to ablation had been ineffective. Thus, our preliminary results suggest that radiofrequency catheter ablation might be beneficial for these high risk patients.     

特发性室性心动过速的射频消融

目的对经射频消融术证实的特发性室性心动过速的病例进行总结分析,探讨室性心动过速的发病状况、心电图特点、消融靶点的确定及消融结果。方法对32例特发性室性心动过速的起源部位和体表心电图进行分析,所有患者在诱发出室性心动过速后进行射频消融治疗,观察特发性室性心动过速的射频消融成功率和复发率,以及它们和消融靶点的关系。结果右室特发性室性心动过速心电图表现为左束支传导阻滞,左室特发性室性心动过速心电图则多表现为右束支传导阻滞。消融靶点的确定右室特发性室性心动过速主要采用起搏标测法,左室特发性室性心动过速主要采用激动顺序标测法。右室流出道室速组在起搏标测起搏ECG和VT时ECG的12导联QRS波完全相同处消融成功率较高。结论室性心动过速发作时的体表心电图可初步估计特发性室性心动过速的起源部位,射频消融术治疗特发性室性心动过速成功率高、并发症少。     

Radiofrequency catheter ablation in recurrent ventricular tachycardia

Catheter ablation by radiofrequency energy was carried out in10 patients with one type of recurrent monomorphic sustainedventricular tachycardia resistant to medical antiarrhythrnicmanagement. Electrophysiological studies before ablation includedactivation and pace-mapping. In all patients, the origin ofthe tachycardia was localized in the left ventricle; in theseptum in six, at the posterolateral wall in three and anterobasalin one. The earliest onset of endocardial activation precedingthe QRS complex during ventricular tachycardia ranged between-45 and -90 ms. Transcatheter ablation was performed with abipolar or quadripolar catheter using a radiofrequency generator(HAT 100, Osypka). No complications occurred during the ablationprocedure. Thereafter, in all patients, the clinical tachycardiawas no longer inducible by programmed stimulation. During afollow-up period of 22 to 32 months including eight patients,the tachycardia recurred in two; one of these patients subsequentlydied suddenly. A third patient had one episode of a new typeof sustained ventricular tachycardia some hours after catheterablation. In the remaining patients, there was no recurrenceof symptctnatic tachycardia under maintainance of the antiarrhythmicmanagement which, prior to ablation had been ineffective. Thus, our preliminary results suggest that radiofrequency catheterablation might be beneficial for these high risk patients.     

Radiofrequency catheter ablation in recurrent ventricular tachycardia

Catheter ablation by radiofrequency energy was carried out in10 patients with one type of recurrent monomorphic sustainedventricular tachycardia resistant to medical antiarrhythrnicmanagement. Electrophysiological studies before ablation includedactivation and pace-mapping. In all patients, the origin ofthe tachycardia was localized in the left ventricle; in theseptum in six, at the posterolateral wall in three and anterobasalin one. The earliest onset of endocardial activation precedingthe QRS complex during ventricular tachycardia ranged between-45 and -90 ms. Transcatheter ablation was performed with abipolar or quadripolar catheter using a radiofrequency generator(HAT 100, Osypka). No complications occurred during the ablationprocedure. Thereafter, in all patients, the clinical tachycardiawas no longer inducible by programmed stimulation. During afollow-up period of 22 to 32 months including eight patients,the tachycardia recurred in two; one of these patients subsequentlydied suddenly. A third patient had one episode of a new typeof sustained ventricular tachycardia some hours after catheterablation. In the remaining patients, there was no recurrenceof symptctnatic tachycardia under maintainance of the antiarrhythmicmanagement which, prior to ablation had been ineffective. Thus, our preliminary results suggest that radiofrequency catheterablation might be beneficial for these high risk patients.     

射频导管消融治疗特发性室性期前收缩触发的心室颤动／多形性室性心动过速

目的：探讨特发性室性期前收缩（早搏,PVC）触发心室颤动和（或）多形性室性心动过速（VF／PVT）的临床特点及射频导管消融治疗效果。方法：313例无器质性心脏病接受射频导管消融治疗的特发性PVC患者,其中6例发生了由PVC触发的VF／PVT,分析该6例患者的临床资料及射频导管消融治疗效果。结果：该6例患者动态心电图可记录到频发PVC[（16303±5854）次／d],PVC联律间期及基础QT间期分别为（412±44）ms和（407±10）ms。这些参数值在另外307例特发性PVC患者中分别为（15570±4743）次／d、（419±36）ms和（404±8）ms,两组间无显著性差异。313例患者中,有88例记录到由PVC触发的单形态室性心动过速（VT）。PVC触发VF／PVT患者中晕厥发生率（3／6）高于由PVC触发的单形态VT患者（4／88,4．5％,P〈0．05）,PVT的周长[（235±22）ms]则短于单形态VT组[（324±29）ms,P〈0．05]。针对触发VF／PVT的PVC消融后随访的10～36个月期间,所有6例患者未再发生晕厥、VF及心脏骤停。结论：恶性VF／PVT可能由一些特发性PVC诱发,射频导管消融PVC治疗可作为一项有效的治疗选择。     

反复单形室性心动过速的导管射频消融治疗

目的对18例反复单形室性心动过速的消融情况进行分析,并对消融同形室性早搏根治反复单形室性心动过速的可行性、安全性及有效性进行分析.方法18例患者,男性4例,女性14例,年龄19～45岁.心电图及动态心电图均有频发室性早搏和非持续性室性心动过速.征得患者的知情同意书后,电生理检查和消融一次进行,标测和消融同形的室性早搏,采用起搏标测和激动标测相结合的方法,确定室性心动过速的起源处(消融靶点).靶点定位后进行射频消融,温度50～60度,能量30～40W.即刻成功标准为放电后10 s内同形室性早搏和非持续性室性心动过速消失,且静脉滴注异丙肾上腺素不能诱发,观察30 min窦性心律稳定.随访成功标准为术后动态心电图24h室性早搏少于100个,无室性心动过速发作.结果18例患者起源于右心室流出道17例,其中1例存在2种形态的室性心动过速,分别于肺动脉瓣上及瓣下消融成功.起源于左心室流出道1例,于主动脉瓣上左Valsalva窦内消融成功.即刻成功17例.随访平均(23±14)个月,无心动过速复发16例,复发2例,1例于术后3个月复发,再次消融成功,另1例于术后6个月复发,未接受第2次消融.1例术后出现少量心包积液,经放置引流管后好转,无其他并发症.结论消融同形室性早搏是根治反复单形室性心动过速安全和有效的方法.     

Radiofrequency catheter ablation of postinfarction ventricular tachycardia from the proximal coronary sinus

Optimum strategy for radiofrequency (RF) catheter ablation of ventricular tachycardia (VT) after inferior wall myocardial infarction (MI) that originates from the posteroseptal process of the left ventricle is not known. We describe a case report of a 57-year-old man who developed recurrent post-MI VT with ECG morphology consistent with this type of VT (i.e., left bundle branch block pattern with predominant R waves from V2 to V6 and left-axis deviation). Endocardial mapping and entrainment during VT demonstrated a critical isthmus of the reentrant circuit in the proximal coronary sinus. RF application terminated VT and rendered it noninducible.     

射频导管消融治疗特发性室性心动过速(附20例报告)

目的 特发性室性心动过速(IVT)的射频消融(RFCA)研究。方法共收集20例临床诊断IVT患者,男性14例。女性6例,年龄40.5±12.5(21～66)岁,病史7.8±8.8(1～22)年,心动过速时R—R间期为:309±69(240～430)ms。心动过速时心电图呈右束支传导阻滞(RBBB)型8例。左束支传导阻滞(LBBB)型,且Ⅱ、Ⅲ、avF主波向上12例。对20例患者进行心电生理检查及射频消融治疗。结果 20例均获成功,术后1例起源左心室后间隔,1例起源于右心室流出道之室性心动过速分别于术后第3、7天复发,余无室性心动过速复发,亦无并发症。结论RF—CA治疗IVT成功率高,RFCA关键在于靶点标测和标测方法的选择。     

Non-contact mapping to guide catheter ablation of untolerated ventricular tachycardia.

AIMS: The role of a novel non-contact mapping system (ESI 3000, Endocardial Solutions) to guide radiofrequency catheter ablation of untolerated ventricular tachycardia was investigated in 17 patients; 11 with prior myocardial infarction, three with arrhythmogenic right ventricular dysplasia, and three with idiopathic dilated cardiomyopathy. METHODS: Twenty-seven monomorphic ventricular tachycardias were induced (mean cycle 320+/-60 ms, range 230-450 ms), mapped for 15-20 s, and terminated by overdrive pacing or DC shock. Off-line analysis of isopotential activation mapping was performed to identify the diastolic pathway and/or the exit point of the ventricular tachycardia reentry circuit. Radiofrequency current was applied to create a line of block across the diastolic pathway or around the exit point. RESULTS: All 27 ventricular tachycardias were mapped with the non-contact system. The endocardial exit point (-7+/-15 ms before QRS onset) was defined in 21/21 postinfarction ventricular tachycardias, in 3/3 arrhythmogenic right ventricular dysplasia and in 1/3 idiopathic dilated cardiomyopathy ventricular tachycardias, respectively. The diastolic pathway (earliest endocardial diastolic activity: -65+/-49 ms before QRS onset) was identified in 17/21 postinfarction ventricular tachycardias, in 1/3 arrhythmogenic right ventricular dysplasia and in 1/3 idiopathic dilated cardiomyopathy ventricular tachycardias, respectively. Catheter ablation was performed in 25/27 ventricular tachycardias (93%) in 15/17 patients (88%): 16/25 ventricular tachycardias (64%) were successfully ablated in 10/17 patients (59%). Catheter ablation was not performed in two patients or proved unsuccessful in five patients. At a follow-up of 15+/-5 months, there was no recurrence of documented ventricular tachycardia in all 10 patients with successful catheter ablation; in two of them a previously non-documented ventricular tachycardia occurred. A high recurrence of ventricular tachycardia was observed in patients with a failed procedure (5/7: 71%). No major complication or death occurred. CONCLUSIONS: Non-contact mapping can be effectively used to map and guide radiofrequency catheter ablation of untolerated ventricular tachycardias. Given the favourable acute and clinical long-term results, this approach proves to be more effective in patients with postinfarction ventricular tachycardias, in comparison to patients with arrhythmogenic right ventricular dysplasia and idiopathic dilated cardiomyopathy.     

Radiofrequency catheter ablation of atrial tachycardia

Background: Atrial tachycardia is a relatively uncommon arrhythmia which usually responds poorly to antiarrhythmic drug therapy. Transcatheter radiofrequency (RF) ablation is a new therapeutic modality for patients with atrial tachycardia. Aim: This study analyses our early experience with the treatment of atrial tachycardia by this technique. Methods: Thirteen consecutive patients (age 13–63 years) with 15 drug-refractory atrial tachycardia foci were treated with RF catheter ablation. Atrial tachycardia was mapped by seeking the earliest atrial activation in the right atrium in eight patients and in the left atrium in five. Results: Tachycardias were abolished in nine (69%) patients, including two sinoatrial re-entrant tachycardias and seven automatic atrial tachycardias, after 9±10 (range, one to 28) pulses of RF current. Six of these ablated atrial tachycardia foci were right sided and three were on the left. One patient had three separate right atrial tachycardia foci; one was eliminated. Tachycardia recurred after two weeks in one patient with apparently successful ablation of sinoatrial re-entrant tachycardia. One patient with successful ablation of a right atrial tachycardia developed cardiac tamponade requiring surgical intervention. Conclusion: This study demonstrates that atrial tachycardia arising from diverse sites can be eliminated by RF catheter ablation.     

射频消融治疗室性早搏触发特发性室性心动过速／心室颤动的病例分析

目的探讨射频消融治疗在室性早搏（室早）触发特发性室性心动过速／心室颤动（室速／室颤）中的作用。方法总结3例由室早触发室速／室颤的治疗经验,1例对室早进行射频消融（RF—CA）并植入心律转复除颤器（ICD）,另1例经射频消融未完全消除室早而选择植入ICD,第3例经射频消融成功消除室早,未再发室颤。结果随访2年,3例患者均存活,ICD未再记录到室速／室颤。结论在室早触发室速／室颤病例中,应分析室早与室速／室颤的相关性,给予个体化治疗,射频消融室早可以消除／减少晕厥和室颤的发作。     

射频消融治疗特发性室性心动过速疗效观察

目的 :评价射频消融术治疗特发性室性心动过速 (室速 )临床疗效。方法 :5 6例特发性室速患者中 ,34例左室特发性室速采用EPT小、中弯大头导管 (或Webstr小弯大头 ) ,在左室行激动顺序标测和消融 ,以P电位较QRS起点提前 2 0ms以上作为消融靶点。 2 2例右室流出道室速采用Webster加硬导管在右室流出道行起搏标测 ,以起搏时与心动过速时体表 12导联QRS形态完全相同或最接近处为消融靶点 ,成功标准为放电过程中心动过速终止且不能诱发。结果 :5 1例患者消融成功 ,成功率 91.1%。 34例左室特发性室速中 30例靶点位于左室间隔中下部 ,2例近左室心尖 ,1例左室流出道 ,1例位于间隔高位。 31例消融成功 ,1例失败 ,2例因导管到达间隔处机械刺激终止室速而不能再诱发 ,于终止室速处作为靶点射频消融 ,1例于术后第 2天、另 1例半年后室速复发。 2 2例右室流出道室速 ,16例位于流出道间隔侧 ,6例位于流出道游离侧壁。 19例起搏标测到与心动过速 12导联QRS形态完全相同靶点 ,1例形态接近 ,消融获成功。 2例未能诱发室速 ,射频消融 1个月心动过速重新出现 ,所有患者无并发症出现。结论 :射频消融术对特发性室速是一种安全有效的治疗方法 ,可作为首选治疗。电生理未诱发室速或机械刺激终止室速不宜尝试射频消融治疗。     

心腔内超声心动图指导下经导管射频消融治疗左心室后乳头肌室性早搏

目的左心室后乳头肌起源的室性早搏（室早）因其体表心电图与左后分支参与的特发性室性心动过速（室速）一样,都表现为心电轴左偏,伴右束支阻滞合并左前分支阻滞,因此有相当一部分被误认为分支室早。为了明确二者起源点的异同,我们采用术中心腔内超声心动图（ICE）来实时监测消融靶点的确切解剖位置。方法选择3例频发室早患者（男2例,女1例）,平均24h室早30000多次,超声心动图均未见心脏结构异常。在三维电解剖系统（CartoXP）指导下,跨主动脉瓣逆行送入3．5mm冷盐水磁定位标测电极导管于左心室,以激动标测构建左心室内膜图。以室早时提前最多;起搏时能得到12／12导联一致的QRS波以及放电20S内室早逐渐减少和消失作为理想靶点标准。在理想靶点确认后,经ICE确认消融导管在左心室内的确切位置,并记录和分析其局部双极电位图。以既往消融成功的经典左后分支室速作为对照,比较两者之间心电图的异同,为以后的标测和消融提供真实可靠的参照。结果ICE证实该3例室早靶点均位于左心室后乳头肌根部或中段,其解剖位置与左心室特发性室速靶点明显不在同一位置,其消融位点较特发性室速更靠心尖部;其局部双极电位在窦性心律时偶尔也可记录到浦肯野电位,但在早搏时都不能记录到浦肯野电位,说明其为肌源性起源,而特发性室速靶点无论窦性心律下还是室速时均可记录到清晰的浦肯野电位;体表心电图尽管可鉴别的特征不多,但后乳头肌起源的室早较特发性室速胸前导联（V：～V。导联）QRS时限明显增宽（前者平均124ms,后者仅86ms）,R／S≤1移行也早于特发性室速（后乳头肌室早在V,导联移行为R／S≤1,特发性室速在V,导联才移行为R／S≤1）。消融10余小时后,室早复发。1个月时复查动态心电图,24h平均室早10000余次,二尖瓣功能未受到任何影响。结论通过实时ICE证实,后乳头肌室早无论起源位置、体表心电图形态还是局部靶点电图均与特发性室速有区别,这类室早消融效果较差,易复发。如何在增强消融强度、扩大消融范围和避免乳头肌损伤之间找到平衡点是该类室早消融的重点和难点。     

永存左上腔静脉并发室上性心动过速的射频消融治疗

目的:探讨永存左上腔静脉（PLSVC）并发室上性心动过速（SVT）的射频消融策略。方法: 2008年6月～2011年6月在我科行射频消融的SVT患者1 460例, 17例并发PLSVC。其中房室结折返性心动过速（AVNRT)8例,左侧隐匿性旁路伴房室折返性心动过速（AVRT）6例,阵发性房颤（PAF）3例。结果: 17例患者均经左锁骨下静脉穿刺成功,并放置冠状窦电极,8例AVNRT患者经房室结改良成功;6例左侧隐匿性旁路,4例经主动脉逆行途径消融,2例经房间隔穿刺,在二尖瓣心房侧进行旁路消融;3例PAF患者行房间隔穿刺后行环肺静脉电隔离。消融成功率100%,无手术并发症。结论: PLSVC并发SVT,导管消融治疗仍有较高的手术成功率和较低的手术并发症,但在左锁骨下静脉穿刺的识别、导管消融的技巧及手术并发症的防治方面仍有其特殊性。     

磁导航系统在房室结折返性心动过速导管射频消融中的应用

目的评价磁导航系统对房室结折返性心动过速导管射频消融的指导作用。方法将经过心内电生理检查确诊的房室结折返性心动过速患者随机分为两组,A组采用常规技术和4mm温控导管消融,B组采用磁导航系统和温控磁大头导管消融。两组各入选10例患者,其年龄、性别、心动过速病史和基础心血管疾病具有可比性。比较两组患者如下参数：消融操作时间、患者透视时间、术者透视时间、放电次数、消融能量、成功率、并发症、手术费用。结果两组患者全部一次消融成功,无并发症,术后住院时间相同,随访（7.1±1.4）个月,无心动过速复发。磁导航消融组的操作时间、患者和术者透视时间、放电次数和实际消融能量均明显低于常规消融组,但手术费用高于常规消融组。结论采用磁导航系统指导房室结慢径路导管射频消融能明显缩短消融操作时间及患者和术者的透视时间,减少放电次数,降低实际消融能量。     

左室特发性室性心动过速常规方法消融困难的线性消融

目的:探讨在常规方法消融困难的左室特发性室性心动过速（ILVT）患者中室间隔左室面线性消融的有效性。方法: 18例术中不能诱发持续性心动过速或发作时不能耐受患者,进行室间隔左室面心尖到心底部连线的前1/3～1/2区域,在窦性心律下首先标到蒲肯野氏纤维电位（PP）,向下至室间隔与左室下壁交界、向上至前后间隔中线进行线性消融,术后门诊或电话随访。结果: 所有患者术后即刻均未能诱发出ILVT。随访3~35（23±13）个月,3例/18例（17%）复发,远期成功率达83%,无1例发生永久性的并发症。结论: 对于术中不能诱发持续性心动过速或发作时不能耐受的ILVT患者,室间隔左室面线性消融安全有效,可以作为补救性消融措施。     

Radiofrequency catheter ablation of left ventricular tachycardia in the normal heart

Background: Radiofrequency (RF) catheter ablation is a safe and effective cure for many forms of supraventricular tachycardia. Its efficacy in the cure of right ventricular outflow tract tachycardia, and some forms of left ventricular tachycardia in patients with left ventricular dysfunction, has also been shown. In contrast limited data are available to assess the role of RF catheter ablation in treating idiopathic left ventricular tachycardia (ILVT), an unusual form of tachycardia occurring in patients without demonstrable heart disease.
Aim: To examine the efficacy and safety of RF catheter ablation in patients with ILVT.
Methods: Three patients without structural heart disease and with recurrent drug-refractory ILVT (right bundle branch block and left axis morphology) underwent electrophysiologic study (EPS) to initiate and localise the site of origin of their VT. RF catheter ablation of the VT focus was performed, with success being defined as failure to reinduce VT during incremental infusion of isoprenaline.
Results: In all three patients VT was inducible by rapid right atrial pacing and/or programmed ventricular stimulation, and could be terminated by intravenous verapamil. RF catheter ablation was successful in all patients. The site of successful ablation was common to each patient and was localised to the infero-apical aspect of the left ventricular septum. It was characterised by the recording of the earliest presystolic 'P' potential during both sinus rhythm and induced ILVT. No complications occurred during the procedure. During follow-up periods ranging from six to 12 months there were no symptomatic or documented episodes of recurrent ILVT.
Conclusions: We conclude that ILVT can be safely and effectively cured by RF catheter ablation.