Temperature-controlled radiofrequency catheter ablation of manifest accessory pathways

OBJECTIVES: The primary objectives of this study were to assess the feasibilityof temperature-controlled radiofrequency catheter ablation ofleft and right sided manifest accessory pathways in patientswith Wolff-Parkinson-White syndrome and to gain more insightsinto biophysical aspects of temperature-controlled catheterablation in humans. BACKGROUND: The electrode-tissue interface temperature and other biophysicalparameters are among important variables determining the efficacyand safety of radiofrequency ablation of accessory pathways.Experimental studies have shown that radiofrequency-inducedtissue necrosis can be accurately predicted by monitoring ofcatheter tip temperature. METHODS: 38 consecutive patients (14 f, 24 m; aged 42 ± 12 years)with anterograde conducting accessory pathways (left sided:n=22; right sided: n=l6) underwent temperature-controlled radiofrequencyablation (HAT 200S, Dr Osypka, Germany). The electrode temperaturewas monitored via a thermistor embedded into a 4 mm cathetertip. Power output was adjusted automatically during energy deliveryin a closed loop system (preselected temp.: 70·1 ±5·8°C). RESULTS: Accessory pathway conduction was successfully abolished in allpatients after the delivery of 2·3 ± 2·1radiofrequency pulses (range: 1–9, median: 2). Interruptionof the accessory pathway as evidenced by loss of preexcita tionoccurred after 5·9 ± 5·4 s. At the timeof the interruption of the accessory pathway the catheter tiptemperature measured 54·2 ± 11· 2 °C in patients with left and 44·9 ± 5·0°C in patients with right sided accessory pathways, respectively(P<0·008). Higher temperature levels during left sidedapplications did not shorten the time it took for the effectto appear (left sided accessory pathway: 7· 5 ±6· 3 s, right sided accessory pathway: 3· 7 ±2· 9 s; ns). The catheter tip temperature was significantlyhigher during left compared to right sided applications after5 (52· 1 ± 3· 1 °C vs 47· 2± 4· 3 ° C) and 10s (61· 5 ±6· 2 ° C vs 52· 7 ± 4· 2°C) following initiation of the impulse (P<0· 005).Power output and delivered energy did not differ significantlyat the time of accessory pathway abolition. Peak values of deliveredpower (45· 1 ± 10· 9 W vs 41· 3± 10· 6W; P< 0· 05) and total deliveredenergy (2452 ± 1335 J vs 1392 ± 762 J; P<0·02) were significantly higher in the group of right sided pathwayscompared to left sided applications. The peak temperature measured77· 1 ± 13 °C during effec tive and 69·9 ± 14 °C during ineffective energy applications(P<0· 05). The time it took for the effect to appearwas significantly longer in transiently effective pulses (10·4 ± 7· 2 s) compared to permanently effectiveapplications (5· 9 ± 5· 4 s; P<0·02). Despite temperature control, an abrupt rise in impedancewas observed in 10 of 89 (11%) energy applications. No procedure-relatedcomplications occurred. CONCLUSIONS: Temperature-controlled radiofrequency ablation of manifest accessorypathways is highly effective and safe. The temperature responseis faster and signficantly higher in left-sided energy applicationscompared to right-sided pulses. Peak temperature levels measuredat the electrode tip are significantly higher during effectivethan ineffective pulses. Sudden rises in impedance are not completely prevented during temperature-controlled radiofrequencyablation of accessory pathway, although no procedure-relatedcomplications were noted in this patient cohort. (Eur Heart J 1996; 17: 445–452)     

Electrochemical potentials during radiofrequency energy delivery: a new method to control catheter ablation of arrhythmias.

AIMS: Thermal injury of subendocardial tissue leads to a release of electrolytes and free radicals from the intracellular site creating a change in electrochemical potential (eP) between the distal and the proximal catheter tip electrodes. The aim of the study was to verify the detection of ablation-induced release of electrolytes and free radicals and to assess the suitability of control-line energy delivery at ablation by measuring eP. METHODS AND RESULTS: In vitro tests under constant flow conditions were performed in a 101 bath of physiological saline solution or bovine blood. Endomyocardial preparations of fresh bovine hearts were used. Closed-loop temperature-controlled, irrigated and closed-loop eP-controlled ablations were performed. In vivo animal investigations were performed in six anaesthetized and ventilated pigs. The existence of the eP was established in the tank model and was confirmed in animal investigations. High correlations were found between eP and catheter tip temperature (r=0.87) and between maximum eP and induced lesion size (r=0.85). Also a high correlation (r=0.85, P<0.001) was found between eP and lesion volume. CONCLUSIONS: Control of energy delivery during RF ablation by the measurement of eP is feasible. In comparison with temperature controlled RF ablation, ablation guided by eP-measurement revealed a superior correlation with induced lesion size. Especially during cooled radiofrequency catheter ablation eP is the only parameter for control of energy delivery.     

Catheter ablation of the atrioventricular node using radiofrequency energy

Background: Catheter ablation of the atrioventricular (AV) junction using stored direct current (DC) energy from a standard DC Cardioverter defibrillator was first reported in 1982. Since then many patients have been treated using this procedure for refractory supraventricular arrhythmias, usually atrial fibrillation and flutter. Undesirable thermal effects such as barotrauma and arcing are largely responsible for complications associated with the use of DC energy. This report details our experience of catheter ablation of the AV junction using radiofrequency (RF) energy in a series of 30 consecutive patients. Methods: RF ablations were performed using steerable Mansfield (Webster Laboratories) 4 mm tipped electrodes and locally assembled RF energy delivery system. Results: The procedure was successful in 27/30 (90%) patients using RF energy, while three patients required DC energy to achieve successful AV junction ablation. General anaesthesia was required in nine patients, six of whom required this for cardioversion to sinus rhythm so that an adequate His Bundle spike could be recorded and three for DC ablation. Dual chamber permanent pacemakers with automatic mode switching were implanted in four patients who had paroxysmal atrial fibrillation or flutter and the remainder had ventricular rate responsive pacemakers. Conclusions: In patients with drug refractory paroxysmal atrial fibrillation and flutter and in patients with established atrial fibrillation where control of the ventricular rate is difficult, catheter ablation of the AV junction using RF energy is a safe and effective procedure with a high success rate.     

Carto3在指导阵发性室上性心动过速射频消融术中的应用

目的总结阵发性室上性心动过速(PSVT)射频消融治疗病例,比较应用三维电解剖标测系统Carto3指导PSVT导管消融的疗效及安全性,着重分析永久性Ⅱ°以上房室传导阻滞(AVB)的发生率。方法自1992年1月1日至2017年12月31日间,联勤保障部队第980医院心血管内科共完成PSVT导管消融治疗且资料齐全的病例2098例。使用Carto3前称为二维组,使用Carto3后称为三维组,比较使用Carto3指导PSVT导管消融的疗效及安全性,着重分析永久性Ⅱ°以上AVB的发生率,总结发生AVB的病例特点,分析相关因素。结果共完成PSVT导管消融治疗病例2098例,其中发生永久性Ⅱ°以上AVB 5例,发生率0.24%。二维组1443例,发生永久性Ⅱ°以上AVB 5例,发生率0.35%;三维组655例,未发生永久性Ⅱ°以上AVB。发生AVB的病例中,房室结折返性心动过速2例,后间隔部旁道2例,希氏束旁旁道1例。发生AVB时消融术者手术年限情况:二维时代术者2名,发生并发症时术龄分别是7年和15年,三维时代术者2名,发生并发症时术龄分别是1年和3年。结论间隔部旁道消融和房室结慢径改良有发生AVB的风险,应用三维标测系统指导阵发性室上速消融治疗可显著降低永久性房室传导阻滞的发生风险。     

心室反应在射频消融特发性室性心动过速中作用的临床研究

目的　探讨心室反应 (VR)在射频消融IVT的作用。方法　应用体表心电图、心内膜激动标测及VR相结合的方法射频消融 13例IVT病人。以激动标测初选靶点 ,射频消融试放电产生的VR确定靶点 ,采用VR与VT发作相一致处为靶点消融。结果　 13例IVT即刻消融成功率 13/ 13。VR表现 :(1)窦性心律下消融时出现与VT发作相一致的VR。随后室性心动过速 (VT)中间断出现窦性心律、双发或联律室性早搏 ,最终完全恢复成窦性心律。 (2 )出现与VT发作不一致的VR。结论　以VR与VT发作相一致处作靶点 ,产生与VT发作相一致的VR可被视为有效消融的指标。     

无休止性房室折返性心动过速的电生理机制及射频消融

探讨１７例无休止性房室折返性心动过速（ＩＡＶＲＴ），男１２例，女５例，平均年龄４６±１７岁，平均心动过速持续时间３６±７６天，平均心室率１８０±１７次／分，１７例中５例有心功能不全的表现，其中４例发生心动过速所致的扩张性心肌病。后间隔旁路１２例（左１１例，右１例），左和右侧游离壁旁路分别为２例和３例。显示递减性传导特性慢旁路２例。４例ＡＨ间期延长，平均１６１±６毫秒。在后间隔旁路中６例心动过速时体表心电图Ｖ１导联ＲＰ≥ＰＲ，仅有１例具有慢旁路特性。１７例全部消融成功，射频消融后随访１～３８个月均无发作。５例心功能不全者，心动过速终止后１周心功能明显改善；４例心动过速所致的扩张性心肌病平均随访１２个月，３例心脏大小和功能恢复正常，１例心脏渐趋缩小。研究结果表明，Ｉ－ＡＶＲＴ的电生理机制可能与下列因素有关：（１）旁路位置，后间隔发生率最高；（２）旁路性质，心动过速时体表心电图显示旁路逆传时间延长和慢旁路特性易发生；（３）多种因素导致房室结传导时间延长。射频消融对于根治ＩＡＶＲＴ和防治其导致扩张性心肌病具有重要的临床意义。     

射频导管消融术阻滞经冠状静脉窦传导通路的实验研究

目的　探讨利用射频导管消融术阻滞经冠状静脉窦的电传导通路的方法及可行性。方法　冠状静脉窦口内 5～ 10mm处射频导管消融 ,低位右心房起搏下 ,观察最早激动部位、冠状静脉窦激动顺序和时间、房间隔激动时间、心房激动时间。结果　 (1)冠状静脉窦口或近端射频导管消融可造成经冠状静脉窦电传导通路的完全或部分阻滞。表现在消融前 ,低位右心房起搏时 ,窦口处的电激动明显早于Bachmann束。消融后 ,窦口处的电激动迟于Bachmann束或两者基本一致 ;(2 )消融前后 ,心房激动时间由 (6 1 14± 8 36 )ms延长至 (88 4 3± 19 2 2 )ms,说明低位心房起搏时冠状静脉窦是优势传导通路 ;(3)消融前后的房间隔激动时间及冠状静脉窦激动时间分别为 (2 6 4 3± 8 87)ms对(15 2 8± 10 13)ms和 (39 4 3± 9 78)ms对 (38 0 0± 5 86 )ms。结论　冠状静脉窦近端射频导管消融术阻断经冠状静脉窦的电传导通路的方法是可行的     

经导管射频消融治疗室性心动过速的疗效观察

室性心动过速是临床上较常见的心律失常,可发生于健康人群和各种心脏病患者。由于其可造成严重的症状甚至危及生命,因而需要积极处理,目前导管射频消融已逐渐成为首选治疗。我院近2年经导管射频消融治疗室性心律失常患者11例,现报道如下,以评价其临床疗效及安全性。     

射频消融治疗频发室性期前收缩的随访研究

目的:探讨射频消融治疗频发室性期前收缩的临床效果和安全性.方法:经常规体检、生化检查、X线胸片、心脏彩超、长程心电图等各种检查后,入选室性期前收缩患者98例,其中右心室流出道室性期前收缩82例,左心室流出道室性期前收缩10例,左心室流人道室性期前收缩6例,分别采用起搏或起搏与激动结合的方法进行标测消融,对临床效果和安全性进行总结.结果:手术成功有90例,好转有6例(再次手术成功5例,1例室性期前收缩较前减少),手术失败2例.术后随访6个月～7年,未发生任何手术并发症.结论:射频消融治疗室性期前收缩是一种安全、有效的方法,该技术可进一步推广.     

经主动脉窦途径射频消融心动过速临床研究

目的:探讨经主动脉窦途径导管射频消融治愈的快速性心律失常患者的心电图特点及射频消融情况.方法:回顾性分析17例室性心动过速/室性期前收缩、前间隔房性心动过速及前间隔旁路等该类患者的体表心电图、及消融成功时靶点电图等心电生理学特征.结果:经主动脉窦途径导管射频消融治愈室性心动过速/室性期前收缩12例,其中起源于左冠状动脉窦(左冠窦)10例、右冠状动脉窦(右冠窦)2例;源于无冠状动脉窦(无冠窦)的局灶性前间隔房性心动过速3例及前间隔旁路2例.室性心动过速/室性期前收缩心电图特点:Ⅱ、Ⅲ和aVF导联为高大R波,胸导联R波移行较早,V1导联r/S波振幅比≥30%,r波时限(82.2±16.4)ms,V1导联中r/QRS波时限比≥50%,V5、V6导联为高振幅R波、无s波.有效消融靶点心内电图示心室波明显比体表心电图QRS波提前(35.2±21.6)ms.前间隔房性心动过速均能被心房刺激反复诱发和终止,其心电图特点:房性心动过速时P波间期明显窄于窦律时P波间期,Ⅰ、aVL导联P波正向,Ⅱ、Ⅲ和aVF导联P呈负正双向.在心房标测中提示最早的心房激动在希氏(His)束区,但在主动脉无冠窦内标测的心房激动较His束区的心房波提前,其解剖定位于His束上后方,消融靶点无His束电位.前间隔旁路心电图示:窦性心律时呈窄QRS波形,未见预激波,心动过速呈窄QRS形,在无冠窦内记录到最早心房激动点,且无His束电位.17例均消融成功.结论:源于主动脉窦内的室性心动过速/室性期前收缩、前间隔房性心动过速和前间隔旁路具有相对的心内电生理学特征,常规心内膜途径消融困难时应该考虑从主动脉窦途径标测消融策略,把握消融导管与冠状动脉的关系,导管消融治疗安全而有效.     

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。     

特发性室性心动过速的临床特点和射频消融治疗

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、心电图特点和消融结果.方法对127例特发性室性心动过速的发病年龄、性别、室性心动过速的起源部位和心电图进行分析,观察室性心动过速的诱发率,射频消融的成功率和复发率,分析消融术失败或室性心动过速复发的原因.结果经消融治疗的特发性室性心动过速好发于年轻人,左心室室性心动过速较右心室室性心动过速多见,11.8%的患者室性心动过速发作时可出现11室房逆传.右心室室性心动过速男女比例为1.01.3,额面QRS波平均心电轴为(+82.96±26.18),诱发率为90.2%,射频消融的成功率为85.4%.左心室室性心动过速男女比例为8.61.0,额面QRS波平均心电轴为(-88.15±43.73),诱发率为96.5%,射频消融成功率为93.0%.结论射频消融术是治疗特发性室性心动过速的一项成功率高、并发症少的相对成熟的技术,可以作为特发性室性心动过速的首选治疗手段.     

射频消融治疗快速心律失常复发原因分析

目的　分析射频消融治疗快速心律失常复发的原因。方法　射频消融治疗快速心律失常 30 0例 ,包括房室结折返性心动过速 (AVNRT)、房室折返性过速 (AVRT)、特发性室性心动过速 (IVT)、心房扑动 (AF) ,快心室率心房纤颤房室结改良。结果　其中 10例复发 ,复发率 3 4%。复发病例包括 :AVNRT 2例、AVRT 5例、IVT 2例、AF 1例。结论　分析复发因素可归纳为 :AVNRT :①以双径路现象消失为最佳终点 ;②电生理检查中 ,最长A2 H2 间期 >32 0ms ,复发率增高。AVRT :①选择最佳靶点除强调AV或VA融合外 ,更强调V或A提前 ;②温控消融电极和Swartz鞘的应用可降低复发率 ;③正确识别和处理某些特殊病例。AF :对峡部的消融要达到峡部传导全部阻断。IVT :①选择最佳靶点 ;②导管与组织的密切接触或采用温控消融电极。     

右侧房室旁道导管射频消融治疗的体会

采用导管射频消融术（ＲＦＣＡ）阻断右侧房室旁道治疗房室折返性心动过速５０例，其中单旁道４５例，双旁道４例，三旁道１例，共５６条旁道。首次消融成功率９４％，二次消融成功率１００％。平均随访９个月，３例复发（６％），均经再次消融成功，其余病例未服用任何抗心律失常药物无心动过速复发，术后除１例右后间隔旁道消融后出现一过性Ⅲ°房室传导阻滞外无其它并发症发生。就右侧旁道消融的体会进行了讨论。     

射频消融房室结改良消融前后心脏电生理变化的探讨

目的比较房室结双径路伴房室结内折返性心动过速(AVNRT)患者,射频消融(RFCA)慢径路改良术,消融前、后心脏各部分腔内电生理改变。方法在相同条件下,于消融前、后分别进行腔内电生理检查。记录消融前、后:希氏束电图(HIS),心房有效不应期(A—ERP),功能不应期(A—FRP),心室有效不应期(V—ERP),功能不应期(V—FRP),房室结前传有效不应期(AVN—ERP),前传文氏点(AVN—WKB),房室结逆传有效不应期(VAN—ERP),逆传文氏点(VAN—WKB),将消融前、后心脏各部分电生理参数进行配对,经SPSS统计分析软件进行T检验分析。结果消融前、后:HIS电图,A—ERP,A—FRP,V—ERP,V—FRP,AVN—ERP,及VAN—WKB均无显著差异(P>0.05)。AVN—WKB,VAN—ERP有显著差异(P<0.05)。讨论射频消融房结改良对房室结双径路AVNRT疗效肯定。在消融前、后(急性期)房室结前、逆传电生理均有一定改变。这与消融改变了房室结的部分结构,如大部分病列慢径路消失有关。不同消融部位对房室结传导电理改变产生不同的结果。没有证据表明消融后,45岁以上年龄组房室结传导改变大于45岁以下年龄组。男女不同性别组之间亦无差异。     

A prospective, randomized comparison of temperature-controlled vs manually delivered radiofrequency catheter ablation in patients undergoing atrioventricular nodal modification or accessory pathway ablation

AIMS: In a prospective, randomized study, the effect of temperaturecontrol on radiofrequency catheter ablation was compared in69 patients undergoing atrioventricular nodal modification (n=32)or ablation of an accessory pathway (n=37) METHODS AND RESULTS: Thirty-five patients were randomized to temperature control,34 to manually delivered radiofrequency ablation. The successrate was 92·5% for accessory pathway ablation and 100%for atrioventricular nodal modification. Mapping duration wassignificantly reduced only in patients undergoing atrioventricularnodal modification. The number of applications was higher formanually delivered ablation in patients undergoing atrioventricularnodal modification (5·6 ± 1·1 vs 1·9± 0·4, P=0·004) as was the cumulative energydelivered (5034 ± 1008 vs 2054 ± 517 W, P=0·013)whereas the mean power per application was higher with temperaturecontrol (41·4 ± 1·8 vs 34·1 ±1·1 W, P=0·002). No significant differences inthese parameters were found in patients undergoing accessorypathway ablation. Coagulum formation on the catheter tip wasobserved more often with manually delivered ablation 5·3%vs 0·9%, P=0·026). The success rate with the initiallyrandomized application mode was higher for temperature control(94·3 vs 61·8%, P=0·003). CONCLUSION: Temperature control during radiofrequency current ablation significantlyreduces mapping duration, necessary applications and cumulativeenergy in atrioventricular nodal modification, but not accessorypathway ablation. Coagulum formation on the catheter tip stilloccurs but is significantly reduced compared to manually deliveredradiofrequency current.     

持续性交界性反复性心动过速射频消融治疗的临床应用评价

目的观察射频消融(RFCA)治疗持续性交界性反复性心动过速(PJRT)的疗效.方法对8例持续性交界性反复性心动过速患者,男3例,女5例,平均年龄30.4岁±18.1岁(12～50岁).行电生理检查确诊为PJRT后射频消融治疗.结果8例患者均射频消融成功,术中发现具有递减性传导特性的隐匿性房室旁道是发生持续性交界性反复性心动过速的电生理基础.结论射频消融是根治持续性交界性反复性心动过速的有效方法之一.     

小儿心导管射频消融术的麻醉体会

射频消融术是治疗快速性心律失常安全、有效的方法。本文报导42例小儿心导管射频消融术的麻醉处理，认为咪唑安定和芬太尼静脉复合麻醉具有安全、起效快、麻醉过程平稳、深度适宜、无明显副作用的特点，对手术过程无明显影响，是射频消融术一种安全、可行的麻醉方法。     

射频消融房室结慢径术发生房室传导阻滞的探讨

目的 :分析房室结折返性心动过速 （AVNRT）患者射频消融术 （RFCA）术中、术后发生房室传导阻滞 （AVB）与靶点选择的关系 ,以探讨选择消融靶点的安全性。方法 :选取 AVNRT患者 97（男 34,女 6 3）例 ,在窦性心律下行RFCA,每次放电前多导生理记录仪记录靶点图 ,放电时观察并用多导生理记录仪记录体表心电图及腔内电生理图 ,分析靶点选择与 AVB发生的关系。结果 :在靠近冠状窦口电极的 C区消融时 ,AVB发生率低 ,而在靠近希氏束电极的 A区消融时 ,AVB发生率高 ;靶电图中出现 His时 AVB发生率高 ;靶电图中 His波振幅高者 ,AVB发生率高 ;A/ V比值 <1时 AVB发生率低。结论 :尽量避免在 A区消融 ,RFCA中靶点图呈小 A大 V,不出现 His波均是避免发生 AVB的关键。     

典型心房扑动导管射频消融终点评价

目的 :探讨峡部双向阻滞在射频导管消融 (RFCA)典型心房扑动 (AF)中的临床意义。方法 :将完成RFCA的 4 3例典型AF患者分为 3组 :①A组 ,12例 ,为静脉滴注 (静滴 )异丙肾上腺素 (1～ 5 μg/min)下不能诱发AF者 ;②B组 ,16例 ,为峡部发生双向传导阻滞者 ;③C组 ,15例 ,为在静滴异丙肾上腺素下 (1～ 5 μg/min)峡部双向传导阻滞者。对上述 3组患者进行常规的心内电生理检查及标测 ,下腔静脉至三尖瓣后叶或 (和 )三尖瓣隔叶至冠状窦口的欧氏嵴进行线性消融 ,以静滴异丙肾上腺素下不能诱发AF或峡部双向阻滞为消融终点。结果 :4 3例AF患者全部消融成功。A组中有 1例伴房室结折返性心动过速患者 ,进行房室结慢径改良后 ,AF不能被诱发。B组中有 1例并发房性心动过速及心房颤动患者 ,经过对AF线性消融后房性心动过速及心房颤动亦消失。随访 1～ 6 0个月 ,A组中有 4例复发 ,B组中有 2例复发 ,C组中无一例复发。结论 :下腔静脉、三尖瓣环和冠状窦口之间的峡部是典型AF折返环的一部分 ,RFCA治疗典型AF安全、可靠 ;静滴异丙肾上腺素下峡部双向传导阻滞作为典型AF的终点 ,可减少AF的复发