低右房电图极性改变评价典型心房扑动射频消融结果

目的　在典型心房扑动 (房扑 )射频消融中观察临近峡部的低位右房心内电图极性改变 ,来迅速判断是否形成峡部双向阻滞。方法　对 10例典型房扑患者 ,沿三尖瓣环放置Halo电极 ,Halo远端紧邻峡部消融线 ,房扑发作中消融在房扑终止后行冠状窦起搏 ,窦性心律下消融则同时行冠状窦电极起搏 ,观察紧邻消融线低右房侧的心房电极电图起始部分的主波方向 (H电位 )的极性表现 ,并与最终双向阻滞评价结果比较。结果　 8例在窦性心律下行冠状窦电极起搏时消融 ,2例在房扑发作中消融。 10例患者最终消融结果均为双向阻滞。 2例房扑发作时H电位极性均为负向 ,8例窦性心律下H电位极性均为正向 ,峡部缓慢传导时该极性仍为正向 ,形成双向阻滞后H电位极性变为负向。结论　典型心房扑动行峡部线性消融时 ,行冠状窦起搏观察到紧邻峡部消融线低右房侧H电位的极性改变可能是峡部消融成功的新指标。该指标简单、快速、可靠性高。     

单导管标测在心房扑动射频消融中的意义

目的:探讨单导管标测法在心房扑动(房扑)射频消融中的应用方法和效果。方法:阵发性心房颤动并发房扑患者行肺静脉电隔离术时采用单导管标测法消融房扑30例。所有患者行肺静脉电隔离术后,将10极冠状静脉窦(CS)导管远端2对电极放置于CS内,余位于CS外,并使之有一定的张力,使导管贴靠于三尖瓣环和低右房。用冷盐水灌注消融导管线性消融三尖瓣峡部,房扑发作患者在房扑下消融,窦律患者在CS远端电极起搏下消融,可在术中随时把大头消融导管置于希氏束部位,用于评价是否已完全达双向阻滞,即:起搏CS远端电极,刺激信号至CS近端电极A波的距离大于至希氏束A波的距离,则CS口至低右房单向阻滞;CS近端电极起搏,刺激信号至CS远端电极A波的距离大于至希氏束A波的距离,则低右房至CS口单向阻滞,从而达双向阻滞,CS近端电极起搏所需电压较高,有的患者可达24mA。结果:所用阵发性心房颤动并发房扑患者均成功行三尖瓣峡部线性射频消融,达到双向阻滞,无手术相关并发症,随访4个月～2年,无房扑复发。结论:单导管标测法对房扑患者行三尖瓣峡部线性射频消融操作简单、快速,可完全用于评价消融结果,成功率高,并且节省手术费用。     

射频消融右房后位峡部和间隔峡部治疗典型心房扑动方法的对比研究

报道对23例典型心房扑动(房扑)患者的后位峡部或间隔峡部作线性消融,并比较两种消融方法的疗效。23例患者中,男性19例,女性4例。年龄16～72(55±14)岁。房扑病史6个月～11年。按消融方法随机分组:后位峡部组12例,间隔峡部组11例。两组患者的年龄、房扑病程、心胸比值差异均无显著性。经静脉放置Ｈａｌｏ、希氏束和冠状静脉窦电极导管,进行电生理检查。房扑心律或持续冠状静脉窦口起搏下(窦性心律者),4或8ｍｍ消融电极导管线性消融后位峡部或间隔峡部。后位峡部消融方法:消融线径为三尖瓣环至下腔静脉。间隔峡部消融方法:消融线径为三尖瓣环…     

三尖瓣环传导时间在确定典型心房扑动消融终点中的价值

目的评价三尖瓣环的传导时间在确定心房扑动(房扑)消融终点中的价值。方法19例经体表心电图证实为典型房扑的患者,在心动过速中根据房扑激动顺序及拖带标测证明折返环沿三尖瓣环运行。测定房扑周长(tachycardial interval,TCL)及起搏后间期(post-pacing interval,PPI)。在三尖瓣环与下腔静脉之间的峡部消融,经冠状窦口及低位右心房起搏证明峡部双向阻滞。分别在冠状窦口、冠状窦远端及高位右心房刺激,用大头电极在峡部消融线上记录在3个部位起搏时的双电位间期(double potential interval,DPI),DPI=刺激信号至第二个电位间期(T2)-刺激信号至第一个电位间期(T1);三尖瓣环传导时间(tricuspid valve annulus conductiontime,TACT),TACT=(T1 T2)-(PPI-TCL);计算TACT/TCL。结果19例患者在消融术中均形成峡部双向阻滞,无并发症发生,停用任何抗心律失常药物,平均随访(27±8)个月,复发1例,经再消融后成功。TCL为210~385ms(平均267·21±36·64ms),冠状窦近端测得的PPI为235~390ms(平均291·32±42·88ms),冠状窦远端PPI为273~450ms(平均334·25±43·04ms),高位右心房的PPI为230~385ms(平均277·13±35·91ms)。提示高位右心房及冠状窦口接近折返环(与TCL相比,P>0·05),而冠状窦远端远离折返环(与TCL相比,P<0·05)。经冠状窦口及低位右心房起搏证实峡部双向阻滞后,分别于冠状窦口、冠状窦远端及高位右心房起搏测定DPI,分别为(152·56±56·66)ms,(150·08±48·35)ms及(85·6±34·47)ms。高位右心房起搏时DPI与冠状窦起搏时比较差异有统计学意义(P<0·05)。3个部位计算的TACT分别为(234·72±58·03)ms、(219·73±40·87)ms,(232·3±43·24)ms,差异无统计学意义。三个部位计算的TACT/TCL分别为(0·87±0·14),(0·82±0·12)及(0·91±0·15),差异无统计学意义。结论三尖瓣环传导时间不受起搏部位的影响,仅与环内折返运动时间长短有关。不论房扑周长的长短及双电位间期的大小,只要三尖瓣环传导时间与房扑周长之比接近于1,提示峡部完全阻滞。     

欧氏瓣对老年人Ⅰ型心房扑动射频消融的影响

目的探讨欧氏瓣对Ⅰ型心房扑动(简称房扑)导管射频消融即刻效果的影响。方法28例老年Ⅰ型房扑患者(呈逆钟向折返18例,顺钟向折返10例)在透视解剖标志和Halo电极三尖瓣环标测电图指引下,在房扑发作或冠状窦口起搏时以温控方式消融位于三尖瓣口和下腔静脉口之间的后峡部,消融方向从三尖瓣叶右室侧到下腔静脉开口。预设温度70℃,每点消融30s,每次移动消融电极3～5mm。观察下列指标:①房扑终止和后峡部阻滞时消融电极在消融线上所处的位置;②房扑终止后峡部残存传导间隙在消融线上所处的位置;③房扑终止后继续消融致后峡部完全阻滞的最终消融部位。结果根据右前斜位30°透视影像测得后峡部平均弧长(即消融线)为38.6±9.7mm。28例全部达到后峡部完全阻滞的消融终点,无并发症。与欧氏瓣有关的房扑终止率为100%(17/17),与欧氏瓣有关的后峡部完全阻滞发生率为92.9%(26/28)。结论欧氏瓣是Ⅰ型房扑后峡部消融线终点的重要标志,线性消融时欧氏瓣心室侧易残存传导间隙,消融该部位的残存传导间隙是Ⅰ型房扑后峡部消融的重要环节。     

差异性起搏法对典型心房扑动消融后峡部完全传导阻滞的预测价值

目的探讨一种简单的方法用以鉴别峡部消融线是完全阻滞还是存在缓慢传导,以降低典型心房扑动(简称房扑)消融后的复发率。方法前瞻性研究30例典型房扑患者消融后峡部的传导,放置20极Halo电极,使最远端的两对电极靠近阻滞线,分别起搏这两对电极并在消融线上标测局部双电位或多电位,我们假设局部电位的初始成分和终末成分分别代表消融线两侧的激动,当起搏部位由离消融线较近的电极对转为较远电极对起搏时,刺激信号到局部电位初始电位成分的时间将会延迟,而刺激信号到局部电位终末成分的时间变化取决于阻滞线是否完整。终末电位提前或不变提示完全阻滞,终末电位延迟提示阻滞线上有传导缝隙。结果用传统判断峡部阻滞的方法做参照标准,选取位点进行差异性起搏共54次,峡部完全阻滞前18次,峡部完全阻滞后36次。当起搏部位转为较远电极对时,初始电位均延迟,平均18±9ms,峡部不全阻滞时,终末电位延迟13±7ms,峡部完全阻滞后,终末电位提前12±8ms。差异性起搏对预测峡部完全阻滞的灵敏度达100%,特异度达88.9%。结论差异性起搏可准确鉴别峡部形成完全阻滞还是存在缓慢传导。     

第46课射频消融后诊断下腔静脉—三尖瓣环峡部阻滞的简易起搏方法

前言下腔静脉-三尖瓣环峡部(CTI)消融已成为典型心房扑动(AFL)的治疗方法.最初,治疗的目标是中止心房扑动且不能诱发,而现在接受的终点是下腔静脉-三尖瓣环峡部双向阻滞,以防止复发.鉴别下腔静脉-三尖瓣环峡部阻滞与缓慢传导是困难的,一直提倡"鉴别起搏",该方法关注的是逐渐远离下腔静脉-三尖瓣环峡部的起搏对消融线或附近记录到的电图(EGM)时间的影响.为分析前-后(逆钟向, CCW)传导,选用多极导管于右心房前壁多个层面起搏,用同一导管远端电极对或消融电极导管于下腔静脉-三尖瓣环峡部处作记录.后-前(顺钟向, CW)传导常由冠状窦近端起搏实施,另需一根电极导管起搏右心房间隔中部作鉴别起搏.在后-前传导检测中,下腔静脉-三尖瓣环峡部电图因电压低或多个成分(指多个波,译者加注),难以解释.此外,在下腔静脉-三尖瓣环峡部阻滞的情况下,起搏冠状窦时跨过界嵴的传导酷似下腔静脉-三尖瓣环峡部传导.我们将报道一种简单的方法,无需冠状窦电极导管,根据经下腔静脉-三尖瓣环峡部消融线间隔缘起搏时右心房前壁的激动顺序,评估下腔静脉-三尖瓣环峡部后-前阻滞.这种方法使得整个手术的完成只需两根电极导管:多极参考导管和消融电极导管.     

射频消融心房扑动拖带刺激的电生理特征

探讨射频消融心房扑动 (简称房扑 )拖带刺激的电生理特征 ,更好的理解房扑机制 ,以期提高消融成功率、减少复发率。 5例阵发性典型房扑患者 ,诱发房扑后 ,在高位、低位右房 ,冠状窦口 (CSO)及右房下部的峡部分别进行拖带刺激 ,分析心房激动顺序 ,然后进行三尖瓣环至下腔静脉之间的线性消融。 5例房扑折返环均为逆钟向旋转 ,峡部 ,高位、低位右房及CSO呈现隐匿拖带 ,左房和卵圆窝呈现显性拖带 ,平均放电 9± 6次 ,均达到右房峡部双向阻滞。CSO起搏时体表心电图Ⅱ、Ⅲ、aVF导联P波形态发生改变。结论 :隐匿、显性拖带对判断峡部依赖性逆钟向房扑有较高价值 ,CSO起搏时心内电图激动顺序和体表心电图P波改变可做为判断峡部消融达到双向阻滞的标志     

典型心房扑动消融术后峡部计时间期的变化预测双向阻滞的价值

典型的心房扑动(房扑)是右心房内的大折返所致已成共识，下腔静脉、三尖瓣环峡部是折返环的一部分。因此，射频消融下腔静脉、三尖瓣环峡部并产生峡部双向阻滞，是成功消融典型房扑和减少复发的可靠标志。目前，多采用心房激动顺序或消融部位的双电位技术确定峡部双向阻滞的存在。通过比较房扑成功消融前、后右心房峡部传导时间，从而提出峡部传导时间的延长程度对峡部完全性     

导管射频消融Ⅰ型心房扑动的方法学评价

本文比较在心房扑动 (房扑 )发作时、冠状静脉窦口 (冠状窦口 )起搏和窦性心律 3种情况下对 型房扑进行导管消融治疗的优缺点 ,消融终点是达到后峡部 (三尖瓣环至下腔静脉口 )双向阻滞。　　资料和方法　将 17例阵发性房扑患者随机分为房扑组、起搏组和窦性心律组。房扑组在房扑发作中按下列步骤消融 :1标测三尖瓣隔瓣和下腔静脉口内侧壁的小心房波(A波 )确定消融线路 ;2对上述线路的三尖瓣侧 1/3、中 1/3和下腔静脉侧 1/3分别以 40 W、2 0 W、10 W做连续的线形消融 ;3重复上述过程直到房扑终止 ;4冠状窦口起搏后峡部传导无变化者按起搏…     

Halo导管在射频消融右侧房室旁路中的应用

目的　总结 8例射频消融失败或复发的右侧游离壁房室旁路病例 ,应用 Halo导管再次消融成功的经验。　方法　 8例患者 ,2例为复发病例 ,6例为失败病例。电生理检查时根据 Halo导管电极 (环绕在三尖瓣环的心房侧 )在窦性心律和心室 S1 S1 刺激时记录的心内电图初步判定旁路位置 ,然后用大头电极标测消融。　结果　共 9条旁路 (双旁路 1例 ,单旁路 7例 )全部消融成功。Halo导管电极记录最早 V波者 2例 ,最早 A波者 6例 ,大头电极在 H alo导管电极提示最早 A波的电极对的部位均可记录到与之提前度相同或更为提前的成功靶点图。手术时间及 X线曝光时间与对照组比较差异不显著。　结论　在右侧旁路的复发和失败病例的消融过程中 ,放置 H alo导管 ,能够提高成功率 ,减少复发 ,节省标测时间。     

导管射频消融Ⅰ型心房扑动的方法学评价

比较在心房扑动 (AFL)时、冠状静脉窦口 (CSO)或低外侧右房 (LRA)起搏下和窦性心律 (简称窦律 )下消融Ⅰ型AFL的优缺点。 48例阵发性AFL随机分为AFL消融组、起搏消融组和窦律消融组 ,对下腔静脉口和三尖瓣环之间的后峡部作线性消融 ,终点为后峡部双向传导阻滞。比较三组患者的电生理参数、急性成功率和远期效果。结果 :三组均达到后峡部双向阻滞 ,随访 2 1.8± 5 .6个月无AFL复发。AFL消融组在AFL终止后均不能达到后峡部双向阻滞 ,需继续在起搏下消融。起搏消融组的操作和曝光时间、放电能量和次数小于其他两组 (P <0 .0 5 )。三组在后峡部双向阻滞后记录局部心房双电位的阳性率为 37.5 %。结论 :①对Ⅰ型AFL采用窦律消融法、起搏消融法和AFL消融法都能取得满意的近远期疗效。②后峡部双向传导阻滞是保证近远期疗效的重要消融终点。③在消融部位标测到双电位可作为消融有效的指标 ,但不能代替后峡部双向阻滞作为消融终点。④起搏消融法的操作和曝光时间、放电能量和次数明显少于在AFL和窦律下消融 ,可作为常规方法使用     

Differential Pacing for Distinguishing Slow Conduction from Complete Conduction Block of the Tricuspid-Inferior Vena Cava Isthmus after Radiofrequency Ablation for Atrial Flutter—Role of Transverse Conduction through the Crista Terminalis

Background: Partial conduction block has been suggested a predictor of recurrence of atrial flutter (AFL).Aim: The aim of this study was to assess transverse conduction by the crista terminalis (CT) as a problem in evaluating isthmus block and the usefulness of differential pacing for distinguishing slow conduction (SC) and complete conduction block (CB) across the ablation line.Methods: We assessed 14 patients who underwent radiofrequency catheter ablation of the eustachian valve/ridge–tricuspid valve isthmus for typical AFL. Activation patterns along the tricuspid annulus (TA) suggested incomplete CB across the isthmus. In these patients, atrial pacing was performed from the low posteroseptal (PS) and anteroseptal (AS) right atrium (RA) while the ablation catheter was placed at the ablation line where double potentials (DPs) could be recorded. The pattern of activation of the RA free wall was assessed by a 20-pole catheter positioned along the CT during pacing from the coronary sinus (CS) ostium (CSos) and low lateral RA (LLRA).Results: Faster transverse conduction across the CT resulted in simultaneous or earlier activation of the distal halo electrodes than of the more proximal electrodes, suggesting incomplete conduction block across the isthmus. CB (13) and SC (1) were detected as changes in the activation times of the first and second components of DPs (DP1, DP2) during PS RA pacing and AS RA. Similar changes in the activation times DP1 and DP2 during AS RA pacing as compared to PS RA reflected SC through the isthmus, whereas increased DP1 activation time and decreased of DP2 activation time reflected complete conduction block across the isthmus.Conclusions: Transverse conduction across the CT influences the sequence of activation along the TA after isthmus ablation. Differential pacing can distinguish SC from complete conduction block across the ablation line in the isthmus.     

Relationship between Polarity of the Flutter Wave in the Surface ECG and Endocardial Atrial Activation Sequence in Patients with Typical Counterclockwise and Clockwise Atrial Flutter

Background: The relation between ECG and activation patterns within atria in typical atrial flutter (AFL) patients (pts) has not been defined due to the lack of simultaneous multisite right and left atrial mapping. Methods: In 13 pts with AFL, a Halo catheter was positioned along tricuspid annulus and multipolar catheters were placed in right atrial appendage, His bundle region, coronary sinus (CS), proximal portion of right pulmonary artery (Bachmann's bundle region, BB) and esophagus (Eso) to record right and left atrial activation simultaneously. Results: In counterclockwise (CCW) AFL (11 pts), 9 showed negative flutter wave (F) and 2 positive F in the inferior leads. CCW/negative F; CS electrograms (EGs) were proximal to distal, Eso EGs were inferior to superior and BB activation was later than CS and Eso. positive F; BB activation was earlier than CS. Eso EGs were superior to inferior or simultaneous. In clockwise (CW) AFL (7 pts), 5 showed positive F and 2 negative F. CW/positive F; BB activation preceded Eso and CS. Eso EGs were superior to inferior. CS EGs were proximal to distal (1), middle to proximal, distal (3) or proximal, distal to middle (1). negative F; CS EGs were proximal to distal. CS activation was earlier than BB or CS and BB activation were simultaneous. Eso EGs were inferior to superior. Conclusion: Impulse conduction to the left atrial free wall through either lower or upper interatrial connection is a major determinant of ECG morphology in AFL.     

Ablation of difficult right-sided accessory pathways aided by mapping of tricuspid annular activation using a Halo™ catheter

Objective To demonstrate that the use of a 20-pole catheter (Halo™) positioned around the tricuspid valve annulus (TVA) is helpful in rapidly localising right free wall accessory pathways (AP), enhancing catheter stability during ablation, and leading to increased success in ablating these challenging pathways. Patients and methods Seven consecutive patients who underwent Halo-mapping of right-sided AP were studied. All but one had previously failed ablation. With a Halo catheter deployed at TVA, the accessory pathway location was rapidly identified using the sites of earliest atrial (A) activation during ventricular (V) pacing or orthodromic tachycardia, or earliest V-activation during sinus rhythm or A-pacing were identified. The stability of the ablation catheter was guided fluoroscopically (with reference to the stationary Halo), and electrically (contact artefact between the ablation catheter and Halo poles). Results AP locations were identified by the Halo (anterior in one patient, antero-lateral in one, lateral in two, and postero-lateral in three) where similar local VA/AV intervals were recorded at both the ablation catheter and Halo bipoles recording the shortest VA/AV intervals (four of seven patients), contact artefact between the ablation catheter and those Halo bipoles was seen (six of seven patients), or both (three of seven patients). All APs were ablated successfully after a mean RF duration of 5±2 min, and 25±17 min post Halo deployment without clinical recurrence at 12±4 months follow-up. Conclusion A Halo positioned at the TVA can ease the localisation of right-sided AP, facilitate catheter stability during ablation, and guides successful ablation. Dr Wong is supported by a Wellcome Trust grant (071249/Z/03/Z).     

Usefulness of the polarity in high-density wide range-filtered bipolar mapping to detect isthmus block during radiofrequency ablation of typical atrial flutter

Background: The atrial activation sequence around the tricuspid annulus (TA) cannot always be used to establish whether complete block has been achieved across the cavotricuspid isthmus (CTI) during radiofrequency ablation (RFCA) for typical counterclockwise atrial flutter (CCW-AFL). Aim: We examined whether a change in the polarity of the atrial high-density wide range-filtered bipolar electrograms recorded near the ablation line is an accurate indicator of complete CTI block. Methods: Nineteen patients with CCW-AFL underwent RFCA. Electrograms were recorded around the TA with duodecapolar conventional (2mm × 8mm × 2mm spacing) and high-density (2-mm spacing) Halo catheters. The bipolar electrograms on the high-density Halo catheter recorded from a series of adjacent electrode pairs positioned just lateral to the ablation line were filtered at a bandpass setting of 0.05–500 Hz. The activation sequence on the conventional Halo catheter during coronary sinus pacing (CSp) and inferolateral TA pacing, and the bipolar electrograms on the high-density Halo catheter during CSp were determined before and after RFCA. The final complete CTI block was verified by the presence of widely split double electrograms ≥100 msec along the ablation line. Results: The final complete CTI block was achieved in all the 19 patients. Before RFCA, the polarity of bipolar electrograms was predominantly negative during CCW-AFL and positive during CSp. In 18 of the 19 patients, the bipolar electrograms exhibited the CCW activation and a negative polarity during CSp only after complete CTI block. In one of those 18 patients, additional applications of RFCA changed the polarity of bipolar electrograms positive to negative although the conventional Halo electrogram activation sequence suggested complete CTI block during CSp. In seven patients, who had transverse conduction across the crista terminalis during CSp, the conventional Halo electrogram activation sequence suggested an incomplete CTI block. However, in six of those seven patients, the CCW activation had a predominantly negative polarity of the bipolar electrograms. In one of those seven patients, complete CTI block was unable to be detected even using the high-density Halo catheter. Conclusions: These data demonstrate that the high-density wide range-filtered mapping can identify the CTI block in undetectable cases of complete CTI block or incomplete CTI block by the conventional method. The polarity of the bipolar electrograms recorded just lateral to the ablation line during CSp after RFCA of AFL may be used as a simple and an accurate indicator of complete CTI block.     

Right atrial flutter due to lower loop reentry: mechanism and anatomic substrates

BACKGROUND: The mechanisms of an atrial flutter (AFL) that is more rapid and at times more irregular than typical AFL are unknown. METHODS AND RESULTS: Twenty-nine patients with AFL were studied. Atrial electrograms were recorded from a 20-pole catheter placed against the tricuspid annulus (TA), with its distal electrodes lateral to the isthmus between the TA and the eustachian ridge (ER), and from the His bundle and coronary sinus catheters. Atrial extrastimuli were delivered in the TA-ER isthmus during typical AFL. Episodes of a right atrial flutter rhythm that was different from typical AFL were induced in 3 patients and occurred spontaneously in 3 patients. This sustained AFL, designated as lower-loop reentry (LLR), involved the lower right atrium (RA), as manifested by early breakthrough in the lower RA, wave-front collision in the high lateral RA or septum, and conduction through the TA-ER isthmus. Linear ablation resulting in bidirectional conduction block in the TA-ER isthmus terminated spontaneous LLR in 3 patients and rendered LLR noninducible in all patients. The cycle length of LLR was shorter than that of typical AFL (217+/-32 versus 272+/-40 ms, P<0. 01). Alternating LLR and typical AFL in 1 patient resulted in cycle length oscillation. CONCLUSIONS: LLR is a subtype of right atrial flutter and depends on conduction through the TA-ER isthmus.     

单用消融电极标测和消融左侧隐匿性旁道

目的 单用消融电极于二尖瓣下直接标测（不放置冠状窦电极）对35例左侧隐匿性旁道进行射频消融。方法 右室心尖起搏下用消融电极沿三尖瓣口标测,确认旁道不在右侧后,将消融电极送至二尖瓣下进行标测和消融。结果 34例左侧隐匿性旁道标测到消融靶点,33例消融成功,1例消融失败,1例复发。与使用冠状窦电极标测相比,消融电极直接标测的X线曝光时间、手术时间均增加。结论 单用消融电极可标测和消融左侧隐匿性旁道。     

起源于三尖瓣环附近的室性心律失常的射频消融及心电图特征

目的总结起源于三尖瓣环附近的室性心律失常的射频消融及心电图特征。方法 15例患者,根据心电图和/或动态心电图诊断为室性心动过速(VT)或频发室性早搏(VPC),均接受心脏电生理检查及射频消融治疗。消融成功后,结合靶点分布区域分析体表心电图。结果 15例消融均获成功,根据消融导管的X线影像特征及腔内电图判断均起源于三尖瓣环附近,不同区域起源的VT/VPC心电图表现各具特征,QRS波时限140 ms、肢体导联见切迹、V1导联可见正向起始波及胸前导联移行区间≥V4判断起源于游离壁的特异度分别为100%、100%、100%、91.7%,敏感度分别为81.8%、90.9%、81.8%、100%。结论射频消融是治疗三尖瓣环附近起源的室性心律的安全、有效方法,心电图表现具其特征。     

A unique mapping strategy for localization and ablation of the atrial input of an antegrade only conducting accessory pathway

The standard technique for accessory pathway ablation involves mapping along the mitral and tricuspid annulus to localize the regions of earliest ventricular activation during antegrade pathway conduction, earliest atrial activation during retrograde conduction or detection of an accessory pathway potential. In some cases despite what appears to be appropriate mapping, catheter positioning and adequate power delivery the ablation is not successful. In many of these cases, the pathway is felt to be inaccessible because of a location remote from the mitral or tricuspid annulus that cannot be affected by endocardial power delivery along the annulus. In the case of difficult left sided pathways, some may be reached and ablated via the coronary sinus or its branches. Right sided pathways cannot be approached in this fashion since there is no venous structure analogous to the coronary sinus around the tricuspid annulus. Alternative mapping and ablation techniques for these difficult pathways have included epicardial mapping via direct pericardial access or attempts to localize pathway insertion areas remote from the valve annulus which may be amenable to endocardial ablation. We describe the use of post-pacing interval mapping to localize the atrial input of a right sided antegrade only accessory pathway that was resistant to conventional mapping and ablation strategies.