大折返房性心动过速的电解剖标测和导管射频消融

目的应用电解剖标测系统分析3例大折返房性心动过速(房速)的电生理机制并导航消融。方法3例房速患者(男1例,女2例),平均年龄51±12岁,心动过速病史19±11年。常规电生理检查初步确定房速所在心腔,使用电解剖标测系统构建心房三维模型,完成电压和激动标测,分析心动过速的机制并确定缓慢传导区(即关键峡部),使用冷生理盐水灌注导管消融。结果3例患者临床常规检查初步排除结构性心脏病,电压标测均显示被标测心房存在疤痕区。病例1为围绕三尖瓣环顺钟向的大折返房速,关键峡部位于三尖瓣环与后侧壁的疤痕之间。病例2为围绕上腔静脉逆钟向的大折返房速,关键峡部位于右房侧壁疤痕与上腔静脉之间。病例3为左房8字形折返,关键峡部位于左房顶部的两片疤痕之间。3例患者均在关键峡部消融成功,随访9～10个月未见复发。结论电解剖标测可以揭示大折返房速的基质,阐明折返机制,并有效指导消融。     

“特发性”瘢痕相关性左心房房性心动过速—电解剖标测和消融结果

目的 报道1组无明显器质性心脏病,无外科手术或导管消融史的左心房折返性房性心动过速(房速)的电解剖标测特点及消融结果.方法 共10例[男3例,女7例,年龄37 ～72(57.4±14.6)岁]符合上述特征的左心房房速患者接受电解剖标测和导管消融.结果 所有房速的折返环均位于大面积低电压(双极电压≤0.5 mV)区域内,低电压区域内可标测到1～5(2.6±1.2)个双电位线和/或电静止瘢痕区,这些传导障碍区和左心房固定的解剖屏障(如二尖瓣环)构成各个折返环必经的关键峡部.8例在折返环峡部内可记录到低幅,长时限碎裂电位,平均振幅(0.21±0.05)mV,平均时限(123±14) ms,占心动过速周长43％±5％.选择折返环峡部特别是长时限碎裂电位为消融靶点,10例均通过1～3(平均2次)次局部放电即终止房速,首次消融后2例复发房速,再次消融成功,随访共(14±10)个月,所有患者无房速复发.结论“自发”的左心房广泛瘢痕形成构成本组房速的“致心律失常基质”,折返环内存在的狭窄且传导缓慢的峡部对维持房速非常重要,并易于消融成功.     

非外科手术瘢痕相关性右心房房性心动过速：电解剖标测与消融

目的探讨非外科手术后的瘢痕相关性右心房房性心动过速（房速）的心内电生理和Carto三维电解剖标测特点及消融方法。方法2008年9月至2009年4月我中心诊治的14例无器质性心脏病基础的右心房房速患者,在Carto三维标测系统指导下行心内电生理检查、标测和射频消融。结果14例患者中有4例心内电生理检查和Carto电解剖标测符合右心房大折返性房速且在Carto电解剖电压标测中显示出“自发性瘢痕”,瘢痕分布于右心房游离壁。这4例患者年龄32～48岁,病史（23．40±15．43）个月,曾使用2种以上抗心律失常药物治疗无效。2例患者右心房轻至中度扩大,左心室射血分数均在正常范围,无明显器质性心脏病依据和心外科手术史及导管消融史。3例患者在瘢痕区内标测到缓慢传导的峡部,2例可诱发出三尖瓣峡部依赖性逆时针心房扑动（房扑）。在三尖瓣峡部、上腔静脉与瘢痕之间、下腔静脉与瘢痕之间、瘢痕与三尖瓣环之问,瘢痕与瘢痕之问或瘢痕区内缓慢传导的“峡部”进行线性消融。4例患者均即刻消融成功。随访（4．2±1．8）个月,3例未再发作心动过速,1例偶尔发作非持续性房速,服药控制良好。结论“自发性瘢痕”相关性右心房大折返性房速临床少见,三维电解剖电压标测可提高消融成功率。     

射频消融治疗经右心房游离壁切口术后的双环折返性房性心动过速

目的 总结经右心房游离壁切口术后双环折返性房性心动过速（房速）的发生率及射频消融后长期随访的结果.方法 2007年1月至2012年12月共入选48例在南京医科大学第一附属医院心脏科行经右心房游离壁切口治疗先天性心脏病或获得性心脏病后发作房速的患者.双环折返性房速的定义为心房同时存在两个折返环,同时在折返的可能路径上进行多部位拖带均为隐匿性.结果 共观察到8例患者术中存在双环折返性房速,男4例,平均年龄（40.4±22.0）岁.第1次外科术后至房速发作时间为（79.0±65.2）个月,第1次房速发作至第1次消融的时间为（20.8±28.3）个月,所有患者房速均持续发作.所有患者的双环折返性房速均与三尖瓣峡部以及右心房游离壁切口相关.5例患者在消融三尖瓣峡部过程中,心动周期突然变化;1例患者消融三尖瓣峡部时,心动周期无变化,右心房游离壁多部位拖带为右心房游离壁折返性房速,间隔部位拖带证实此部位不在折返环内,可能提示右心房游离壁折返性房速为主导折返环,;1例患者消融过程中心动过速终止,同样行切口致下腔的线性消融;1例患者消融三尖瓣峡部时心动过速无明显变化,但冠状静脉窦的激动有细微变化,拖带标测提示三尖瓣峡部不在折返环内,右心房游离壁多部位拖带提示为围绕右心房切口瘢痕折返的心动过速,行外科切口下部至下腔静脉消融时,房速终止.平均随访（33.6±16.7）个月,3例复发患者均为风湿性心脏病换瓣术后,其中1例复发房速,另外2例复发房颤.结论 经右心房游离壁切口术后双环折返性房速主要与三尖瓣峡部以及切口相关,三尖瓣峡部以及切口至下腔静脉线性消融常能够治疗这类心律失常.     

左房房性心动过速三维电磁导管标测系统(Carto)标测与射频消融

目的探讨左房房性心动过速(房速)三维电磁导管标测系统(Carto)系统标测特点及射频消融价值.方法 9例左房房速患者,应用Carto系统标测左心房,实时重建左房三维电解剖图;根据电解剖图,判断房速类型局灶性或大折返性房速;于心房最早激动点处或折返环的关键峡部消融.结果 9例患者中共有10个房速.在冠状静脉窦(CS) 电极中、远端或近端均记录到相对提早A波;9个房速为局灶性房速,激动图显示最早激动点位于肺静脉口部(5个)、左房后壁(2个)、左心耳口部(1个)、左心耳体部(1个);1个为大折返性房速,折返经过右上肺静脉口部与卵圆窝之间关键峡部.8个局灶性房速在上述最早激动点处消融,均成功终止房速,1个左心耳体部房速消融失败;大折返性房速于关键峡部行线性消融,获成功;随访6～30个月,其中1例局灶性房速术后次日复发,再次消融成功;无并发症;成功病例手术时间为90～140 min,X线照射时间为8～16 min.结论本组结果提示,应用Carto系统标测左房房速,判断房速类型准确、快速;指导消融安全、有效,可减少X线照射时间,进一步提高消融成功率,特别是对于常规方法消融失败病例尤有帮助.     

心脏外科手术后房性心律失常的三维电解剖标测和射频消融

目的应用Carto系统对心脏外科手术后房性心律失常患者进行三维电解剖标测和射频消融。方法入选心脏外科手术后房性心律失常患者29例,平均年龄（47±13）岁,男性15例,女性14例。在心动过速时,电解剖标测三维重建右心房和／或左心房。根据双极电图电压确定瘢痕区。对于折返性房性心动过速（房速）,线性消融关键峡部或瘢痕区与正常解剖障碍区之间或两瘢痕区间,对于局灶性房速,点消融局部最早激动区域。结果29例患者中,共标测39种心动过速,右心房切口性房速13例（45％）,右心房峡部心房扑动（房扑）19例（66％）,其中单一出现患者11例（38％）,伴发出现患者8例（28％）,即时消融成功率93％（27／29）,无消融术相关并发症发生。随访（26±20）个月,2例复发,1例再次消融成功。结论心脏外科手术后房性心律失常常见为右心房切口性房速和右心房峡部房扑,Carto电解剖标测系统可有效指导射频消融治疗。     

高密度标测指导下射频导管消融房性心动过速

目的 探讨EnSite NavX系统高密度标测对房性心动过速（房速）射频导管消融的指导作用.方法 17例房速患者,平均年龄（45.9±16.9）岁,男性15例,女性2例.心动过速均呈持续性发作,应用EnSite NavX系统于心房进行高密度标测,建立激动图.对于折返性房速,线性消融关键峡部或传导通道（channel）,对于局灶性房速,点消融局部最早心房激动区域.结果 17例患者中,共标测到19种房速,周长为（254±49）ms,平均取点（316±90）个,标测时间为（8.4±2.6）min,建立19种激动图 激动图显示大折返性房速10种,局灶性房速9种 19种房速中,18种即时消融成功 无标测与消融相关并发症发生.随访（3.0±1.6）个月,2例服用胺碘酮可预防发作（1例患者房速复发,1例患者术中有1种房速未消融成功）.结论 EnSite NavX系统高密度标测对心动过速机制可作出快速、准确的判断,有助于确定消融靶点,提高消融成功率.     

应用CARTO系统标测和消融房性心动过速的初步经验

初步探讨CARTO系统在房性心动过速 (简称房速 )标测和射频消融中的临床应用。 5例房速患者 ,年龄 42 .4± 15 .8岁 ,男 3例、女 2例。其中 1例为法氏三联症外科根治术后。心动过速周期 35 5± 76ms。在心动过速时应用CARTO系统标测相关心房 ,实时重建三维电解剖图 ,并用以指导射频放电消融靶点。 5例房速均成功消融。 3例为右房内折返性心动过速 ,其中 1例法氏三联症手术后房速为右房外侧壁手术瘢痕所介导 ,经线性消融关键峡部成功。 2例为局灶性房速 ,起源点分别在右房His束旁和左房后壁。放电次数为 3.5± 2 .1。手术时间为 2 39± 45min ,曝光时间为 14± 9min。结论 :本研究提示应用CARTO系统标测和消融房速 (包括折返性和局灶性 )是可行的。在较少X线曝光下 ,易于标志到最佳靶点和成功消融 ,尤其是对于心脏结构异常和复杂房速的病例。     

射频消融治疗风湿性心脏病二尖瓣置换术后房性心动过速

目的报道一组风湿性心脏病二尖瓣置换术后房性心动过速（房速）的机制及射频消融效果。方法共入选22例（男8例）二尖瓣置换术后持续性房速患者,在心动过速状态下采用三维电解剖系统建立右心房或左心房激动标测图和电压图,标出瘢痕区、低电压区及双电位区,并揭示心动过速的机制。根据标测结果选择心动过速的关键峡部或起源点进行消融。结果22例患者共标测33种心动过速,17例次房速起源于右心房（51．5％）,16例次房速起源于左心房（48．5％）。符合大折返机制的31例次（93．9％）,符合局灶起源机制的2例次（6．1％）。消融术中即时成功率90．9％（20／22）。随访过程中5例患者仍有房速发作,3例再次消融成功。结论二尖瓣置换术后房速机制复杂且个体化,在三维电解剖标测指导下射频消融治疗效果满意。     

导管射频消融治疗先天性心脏病外科术后房性心动过速分析

目的总结先天性心脏病(简称先心病)患者外科术后房性心动过速(简称房速)的电生理机制、导管射频消融方法及结果。方法入选先心病外科术后房速患者,首先行电生理检查明确房速起源心腔。之后在三维标测系统(CARTO或EnSite-NavX)指导下行靶心腔的电解剖标测,明确房速机制后对大折返关键峡部或局灶房速的最早激动点进行消融。结果共入选26例,诱发出30种心动过速,其中单纯为三尖瓣峡部依赖性心房扑动(简称房扑)13例;单纯右房疤痕折返房速4例;右房疤痕房速合并房扑6例,其中3例为两者同时存在形成"8"字折返,3例为两者先后出现;单纯局灶性房速2例;合并有疤痕折返及局灶两种机制的1例。首次消融手术成功率96.2%(25/26),随访(38±23)个月,有6例患者复发。共经三次消融后,总体手术成功率88.4%(23/26)。结论先心病外科术后的房速以三尖瓣环大折返房扑最为常见,其次为游离壁大折返;总体而言,射频消融成功率较高。     

Non-fluoroscopic electroanatomical mapping (CARTO system) in the ablation of atrial tachycardias

INTRODUCTION AND OBJECTIVES: The recent introduction of navigation systems has made substantial improvements in cardiac electrophysiological mapping. We present our experience with non-fluoroscopic electroanatomical mapping in patients with atrial tachycardias. PATIENTS AND METHOD: We studied 24 consecutive patients with atrial tachycardias (10 of whom had undergone previous radiofrequency ablation which failed). In all patients we performed electroanatomical mapping of the atria with the CARTO system, which combines electrophysiological and spatial information and allows visualization of atrial activation in a three-dimensional anatomical reconstruction of the atrial cavity. Mapping was performed during tachycardia (22 patients) or in sinus rhythm (2 patients), using a left atrial approach in 12 patients. Cooled-tip ablation was performed in 3 patients. RESULTS: Three-dimensional mapping distinguished clearly and rapidly between reentrant (9 patients) and focal mechanisms (15 patients). Radiofrequency catheter ablation was aimed at the critical isthmus of conduction (voltage maps) in patients with macroreentrant tachycardias. For focal tachycardias the catheter was re-navigated within the target area (activation maps) to the earliest focus of ectopic impulses. Acute success was obtained in 19 patients (79.2%), with early recurrence in 2 of them. Fluoroscopy time was 60 (21 min). CONCLUSIONS: Visualization of atrial activation in a three-dimensional reconstruction of the atria with the CARTO electroanatomical mapping system facilitated the integration of electrophysiological and anatomical information in patients with atrial tachycardias. This technique is potentially helpful in ensuring successful treatment of the substrate of tachycardia in this selected group of patients.     

Electroanatomical mapping for visualization of atrial activation in patients with incisional atrial tachycardias.

AIMS: Incisional atrial tachycardias in patients following surgery for congenital heart disease are based on complex structural abnormalities in these hearts. The aim of this study was to evaluate the use of the electroanatomical mapping system, CARTO, in consecutive patients with different forms of incisional atrial tachycardia. METHODS AND RESULTS: The electroanatomical mapping system combines electrophysiological and spatial information and allows visualization of atrial activation in a three-dimensional anatomical reconstruction of the atria. Electroanatomical mapping of right atrial activation was performed in 10 patients after surgery for congenital heart disease, surgery for Wolff-Parkinson-White syndrome, or heart transplantation presenting with 13 incisional atrial tachycardias. The three-dimensional mapping allowed a rapid distinction between focal (n=3) and reentrant mechanisms (n=10) and visualization of the activation wavefronts along anatomical and surgically created barriers. Electroanatomical activation maps (mean right atrial activation time 213+/-107 ms) were constructed with 89+/-60 catheter positions during an average mapping time of 48+/-33 min. Reentrant tachycardias propagating through the tricuspid annulus-vena cava inferior isthmus (n=6) or along periatriotomy loops (n=4) were identified in eight patients. Ectopic atrial foci near surgical scars could be localized in three patients. Catheter ablation by creation of a lesion in a critical isthmus of conduction or by targeting the arrhythmogenic focus eliminated 11 of 13 incisional atrial tachycardias. CONCLUSION: Visualization of atrial activation in a three-dimensional reconstruction of the right atrium using the electroanatomical mapping system CARTO facilitates understanding of the mechanism and defines the reentrant circuits of incisional atrial tachycardias. This new method may improve the success rate of electrophysiologically guided and anatomically guided catheter ablation of incisional atrial tachycardias.     

Three-Dimensional Electromagnetic Catheter Technology:

Electroanatomical Mapping. Introduction : The difficult catheter orientation and navigation associated with conventional technology and mono-/multiplane fluoroscopy may complicate ablation procedures of atrial tachycardias. A new three-dimensional catheter technology for electroanatomical mapping of the right atrium and ablation of ectopic atrial tachycardia is described.
Methods and Results : A novel electromagnetic catheter-based mapping system was investigated for electroanatomical mapping of the entire right atrium in 12 patients. The system reconstructed three-dimensional maps from the multitude of endocardial sites that were sequentially mapped and color coded the individual activation times. The electrophysiologic information was superimposed on the geometry of the mapped area. The anatomical landmarks of the right atrium, i.e., the tricuspid annulus. mouth of the coronary sinus, ostia of the superior and inferior venae cavae, and right atrial appendage, could he depicted in all cases. The sinus node area and the preferential conduction along the crista terminalis could be delineated. In four patients with ectopic atrial tachycardia, the earliest endocardial activation could be identified with high spatial resolution as a "hot spot." After completion of the mapping procedure, the ablation catheter could be reliably renavigated to the site of origin, and ablation was successful with one or two impulses. In one patient with previous atrial septal repair, the activation map allowed the reconstruction of a long line of conduction block induced by the atriotoniy.
Conclusion : Three-dimensional electroanatomical mapping of the right atrium allowed detailed reconstruction of the chamber geometry and activation sequence. The sites of origin of ectopic atrial tachycardias could be identified precisely. The system allowed accurate renavigation to the site of earliest activation, thereby guiding successful ablation of the foci.     

CARTO标测指导射频消融治疗非峡部依赖性心房扑动的初步研究

初步探讨非峡部依赖性心房扑动 (简称房扑 )———非典型房扑CARTO标测的方法学和射频消融效果。 4例经电生理标测证实的非典型房扑患者 ,男、女各 2例 ,年龄 2 4～ 5 7岁。 1例为先天性心脏病 (简称先心病 )三房心外科术后 ,1例为慢 快综合征。房扑发作时在右房或左房CARTO标测 ,三维重建右房或左房 ,寻找房扑折返径路的关键峡部区域行线性消融。结果 :3例为右房非峡部依赖性房扑 ,1例消融径线为 2条 ,即三尖瓣环至下腔静脉(IVC)口和右房后外侧至IVC ,1例消融径线为右房前中外侧 ,1例为右房下外侧。 1例左房房扑 ,消融径线位于右上肺静脉口下方至卵园窝。 4例均即时消融成功。随访 8～ 2 4个月 ,有 1例先心病术后房扑复发 ,再次行CARTO标测发现房扑折返环位于左房 ,划线消融未成功。结论 :CARTO标测非峡部依赖性房扑有一定的优势 ,能显示房扑折返环和关键峡部 ,并能指导线性消融     

Feasibility of combination mapping utilizing a duo-decapolar electrode catheter and the CARTO system for incisional reentrant atrial tachycardia with cycle length alternation: a case report

A 43-year-old woman had undergone patch closure operation for atrial septal defect 27 years ago. She was referred to our hospital for evaluation of frequent palpitations since 1 year ago. Electrophysiological study was performed with recording of the coronary sinus, His bundle, and low lateral right free wall electrography utilizing a steerable duo-decapolar electrode catheter(Livewire, Daig). Supraventricular tachycardia with cycle length alternation of 300 and 320 msec similar to atrial flutter was reproducibly provoked by burst pacing from the coronary sinus. During the supraventricular tachycardia, abnormal atrial potentials occurred in the low lateral right free wall region with very low amplitude and splitting potentials. The cycle length alternation of the supraventricular tachycardia depended on the occurrence of the splitting potentials, that is, the splitting potentials were present during the supraventricular tachycardia with a long cycle and the splitting potentials were absent during the supraventricular tachycardia with a short cycle. This phenomenon suggested that the splitting potentials resulted from 2:1 functional intra-atrial local conduction block. In addition, during sinus rhythm the abnormal electrograms revealed fractionated activity. Thus, these findings strongly imply that the supraventricular tachycardia is due to a macro-reentrant right atrial tachycardia utilizing an anatomical obstacle caused by the atrial septal defect operation as a central area, namely incisional reentrant atrial tachycardia. Three-dimensional electroanatomical mapping using the CARTO system(Biosense-Webster) was conducted to investigate whether the low lateral right free wall area possessed the critical isthmus essential to the reentry circuit. Electroanatomical mapping revealed that the very low amplitude potentials and the splitting potentials corresponded to the scars and the functional conduction block area detected by mapping using the multipolar catheter, respectively. According to the propagation mapping, the incisional reentrant atrial tachycardia slowly conducted the channel created by multiple neighboring scars clockwise and the alternation of the tachycardia cycle length was dependent on the development of the functional local intra-atrial conduction block within the channel. An approximately 1.5 cm successful linear lesion was created by radiofrequency catheter ablation to transect the isthmus based on the electroanatomical mapping findings. Afterwards, the incisional reentrant atrial tachycardia could not be induced by burst stimuli from the coronary sinus even under administration of isoproterenol. The use of three dimensional electroanatomical mapping(CARTO system) to evaluate the reentry circuit after the detection of abnormal potentials by using multipolar catheter in advance is a very useful method to determine optimal target site of ablation for a patient with incisional reentrant atrial tachycardia.     

Electroanatomic mapping of entrained and exit zones in patients with repaired congenital heart disease and intra-atrial reentrant tachycardia

BACKGROUND: Characterization of reentrant circuits and targeting ablation sites remains difficult for intra-atrial reentrant tachycardias (IART) in congenital heart disease (CHD). METHODS AND RESULTS: Electroanatomic mapping and entrainment pacing were performed before successful ablation of 18 IART circuits in 15 patients with CHD. Principal features of IART circuits were atrial septal defect (4 patients), atriotomy (3 patients), other atrial scar (3 patients), crista terminalis (3 patients), and right atrioventricular valve (5 patients). A median of 176 sites (range, 96 to 317 sites) was mapped for activation and 13 sites (range, 9 to 28 sites) for entrainment response. Postpacing intervals within 20 ms of tachycardia cycle length and stimulus-to-P-wave intervals of 0 to 90 ms (exit zones) were mapped to atrial surfaces generated by electroanatomic mapping. Criteria for entrainment were met over a median of 21 cm2 of atrial surface (range, 2 to 75 cm2), 19% (range, 1% to 81%) of total area tested. Using integrated data, relations between activation sequence and protected corridor of conduction could be inferred for 16 of 17 LARTs. Successful ablation was achieved at a site distant from the putative protected corridor in 9 of 18 (50%) circuits. CONCLUSIONS: The right atrium in CHD supports a variety of IART mechanisms. Fusion of activation and entrainment data provided insight into specific IART mechanisms relevant to ablation.     

New Mapping Technology for Atrial Tachycardias

Prerequisite for succesful radiofrequency catheter ablation of tachycardias is the exact mapping during the electrophysiological study. The new mapping system CARTO allows a three-dimensional color-coded electroanatomic map of impulse propagation using electromagnetic technology. The aim of this study was to determine the feasibility and safety of the new electromagnetic mapping technology CARTO for atrial tachycardias.Results: Electrophysiologic study and CARTO mapping was performed in 38 atrial tachycardias. The mapping procedure took 26 ± 23 min. We created 33 maps within the right atrium and 5 maps within the left atrium with a mean of 74 ± 38 different catheter positions. The mechanism was determined as reentrant in 9, junctional in 1 and focal in 28 tachycardias. In focal tachycardias the tachycardia cycle length (CL) and the total atrial activation time (AT) were clearly different (352 ± 98 ms vs 99 ± 25 ms). Reentrant tachycardias had a comparable CL and AT (236 ± 44 ms vs 240 ± 56 ms). In 83% of the focal tachycardias and in 67% of the reentrant tachycardias, ablation was performed successfully. No complications occured.Conclusion: The electroanatomic mapping system allows high resolution visualization of electrical activity and may therefore improve precision and simplify the determination of the arrhythmogenic substrate during tachycardias for successful catheter ablation.     

Double loop reentrant atrial tachycardia following ablation for atrioventricular nodal reentrant tachycardia

We report a patient with a history of multiple ablations for recurrent atrioventricular nodal reentrant tachycardia who developed an atrial tachycardia four years after his last procedure. Subsequent electroanatomical mapping demonstrated double loop macro-reentrant atrial tachycardia consistent with a roof dependent flutter and a perimitral flutter. We successfully terminated the tachycardia by targeting isthmuses at sites of prior ablation.