环肺静脉左心房线性消融术后复发的房性心律失常

目的研究心房颤动(房颤)患者环肺静脉左心房线性消融术后复发房性心律失常的机制。方法28例房颤患者接受环肺静脉左心房线性消融术,平均年龄(54±11)岁,其中阵发性房颤10例,持续性房颤18例。采用Carto电解剖标测系统及双Lasso标测导管技术,分别进行环左、右侧肺静脉线性消融;消融终点为肺静脉电位消失,左心房-肺静脉双向阻滞。复发患者再次消融术采用双Lasso导管指导在原环形消融线上标测“漏点”并消融封闭之,对不能终止心动过速者再行拖带标测、激动标测或结合Carto系统标测;对典型心房扑动(房扑)行右心房峡部线性消融。结果初次消融术后平均随访(245±65)d,18例无复发;8例复发房性心律失常包括5例典型房扑、2例其他房性心动过速、1例阵发性房颤;2例左上肺静脉电位未完全隔离者仍持续房颤。除外1例持续性房颤,另外9例接受了再次消融术,证实所有复发患者均有左心房-肺静脉传导恢复;8例射频消融成功并随访(192±92)d无复发。结论左心房-肺静脉传导恢复是环肺静脉左心房线性消融术后复发房性心律失常的重要因素;初次手术附加右心房峡部线性消融可能减少复发率。     

双Lasso导管和三维标测指导下环肺静脉线性隔离术治疗心房颤动

目的在双Lasso导管和三维标测指导下环肺静脉线性消融并彻底隔离肺静脉以治疗心房颤动(简称房颤)。方法28例房颤患者接受射频消融治疗,其中阵发性房颤12例,持续性房颤16例。所有患者首先利用三维电解剖标测系统(CARTO)进行左房重建,然后将两根Lasso导管同时置入右(左)上下肺静脉内,在肺静脉口外0.5~1cm左右行环肺静脉线性消融,消融终点为左房-肺静脉完全性传导阻滞。结果28例均电隔离成功,肺静脉完成隔离后,共86.6%(97/112)的肺静脉内可见缓慢自律性电活动。手术时间205±67min,X线透视时间27±16min,无并发症发生。术后随访8.5±3.7个月,23例无房颤复发,总成功率82.1%。结论双Lasso导管和三维标测指导下有明确电学隔离指标的环肺静脉线性消融术治疗房颤安全而有效。     

肺静脉冷冻消融电隔离治疗心房颤动的即刻效果

目的探讨冷冻消融行肺静脉电隔离的即刻效果。方法选择临床确诊心房颤动(房颤)患者20例,阵发性房颤16例,持续性房颤4例。采用北极圈冷冻消融导管冷冻隔离肺静脉,Lasso导管标测肺静脉电位,肺静脉电位消失30 min为消融隔离成功。结果平均手术时间(265.88±52.20)min,曝光时间(43.42±17.23)min。实际电隔离57支肺静脉,平均每支肺静脉消融(5.64±2.57)次。2例持续性房颤在消融中终止,2例消融后电转复。7支肺静脉(占总消融肺静脉12.28%)在电位消失后30 min内恢复传导,再次行冷冻消融成功。消融即刻成功率100%。结论经导管冷冻肺静脉电隔离即刻效果较好。为减少复发,隔离后的等待时间是必要的。     

阵发性心房颤动患者肺静脉前庭电生理现象及分析

目的采用EnSite/NavX系统指导下,结合单Lasso进行环肺静脉电隔离术治疗阵发性心房颤动(简称房颤),分析消融过程中肺静脉前庭电生理现象。方法入选2004年10月~2005年12月症状性阵发性房颤患者143例,男85例、女58例,年龄60.7±10.3(35~80)岁,房颤病程5.5±6.7年(21天~50年),左房内径36.9±6.4(24~54)mm。在EnSite-NavX系统引导下行环肺静脉消融达到肺静脉电隔离。结果143例完成环肺静脉隔离术,手术时间157±30(90~240)min,放射线时间25.8±8.8(9.8~60.1)min。环单侧左、右肺静脉前庭消融电隔离率分别为81.2%、78.3%,其余病例结合节段性消融(SOA)达到肺静脉电隔离。房颤终止的比例为69.7%(23/33例),第一次消融63.6%(91/143)可记录到肺静脉内自发电位,2.1%(3/143)可记录到肺静脉内快速的自主节律,而体表心电图为稳定的窦性心律。房颤复发患者第二次消融时,所有21例均有肺静脉电位(PVP)恢复,其中第一次消融时结合SOA达到肺静脉隔离的患者:57.1%左侧PVP恢复,55.6%右侧PVP恢复。第二次消融时,85.7%(18/21)例存在肺静脉内自发电位。术后房性心动过速/心房扑动15例(10.5%),12例再次行射频消融治疗,11例消融成功。术后随访10.7±4.9(4~18)个月,包括第二次消融术后患者在内,共90.2%(129/143)在无抗心律失常药物治疗下无房颤发作。心包积液2例,Ensite/NavX电极贴片故障1例。结论心房-肺静脉传导存在优势传导径路,且传导方式并非“全或无”;结合SOA的消融方法复发率较高;多数患者肺静脉隔离后可记录到自发肺静脉电位,复发患者的肺静脉通常具有较高的兴奋性。     

阵发性心房颤动的射频导管消融大静脉电隔离治疗

目的报道阵发性心房颤动(房颤)的射频导管消融电隔离肺静脉和腔静脉的疗效。方法阵发性房颤患者36例,年龄(42.5±13.2)岁。经1次房间隔穿刺放置环状标测电极导管(Lasso导管)和冷盐水灌注消融导管,在Lasso导管的指导下,采用全肺静脉或上腔静脉与靶静脉节段性电隔离相结合的方法对肺静脉和腔静脉行标测和电隔离治疗。窦性心律时最早激动的肺静脉和腔静脉电位处和/或心房起搏时最短的心房和静脉电位间期处为靶点行消融。结果36例阵发性房颤患者均接受一次电隔离治疗,共电隔离大静脉115根,其中左上肺静脉34根,左下肺静脉22根,右上肺静脉30根,右下肺静脉17根,上腔静脉12根,即刻电隔离成功率为95.6%,术中并发症发生率2.78%。随访3~22个月,成功率(无房颤发作或房颤发作明显减少)为75.0%。结论射频导管消融电隔离肺静脉或腔静脉与心房间的电活动连接,可有效预防房颤的复发。治疗的关键是消融靶点的标测和确定。     

电生理标测指导下肺静脉电隔离术治疗慢性心房颤动

目的探讨电生理标测指导下的肺静脉电隔离术治疗慢性心房颤动(房颤)的可行性.方法 20例慢性房颤患者,男14例,女6例,年龄56～72岁(平均68±7岁);房颤病史1～9年(平均3±7年),经过至少一次的体外同步心脏电复律,房颤均在30 min内复发.电生理标测指导下的肺静脉隔离方法为(1)最早激动点指导下消融.肺静脉内的Basket导管记录的心房电活动显示节律较规整,激动顺序一致.(2)房颤长间歇(连续记录的最长心房电活动间期>300 ms)指导下消融.肺静脉内电位节律紊乱,激动顺序不一致,房颤长间歇后的第一次心脏搏动的最早激动部位为消融靶点.(3)3型房颤波指导下的消融.房颤频率快,肺静脉内Basket导管记录的电活动激动顺序紊乱,部分电极记录的心内电图等电位线消失而不能确定孤立的心房电活动(3型房颤),此部位作为消融靶点.在房颤过程中完成4支肺静脉电隔离后,房颤不能自发终止者应用体外同步电复律.重新将Basket 导管放入肺静脉,仍记录到肺静脉电位者将在窦性心律下完成电隔离.结果 (1)临床结果所有患者在肺静脉隔离后成功转复为窦性心律,其中1例患者自行转复为窦性心律,2例患者转为心房扑动,经右心房峡部消融后转为窦性心律,余患者经体外同步电复律转为窦性心律.随访3～19个月(平均8±9个月),维持窦性心律者9例(45%),11例(55%)患者复发,无有症状性的肺静脉狭窄.(2)消融结果20例患者的76 支肺静脉电隔离被完成.68支(89.5%)肺静脉电隔离在房颤中完成,其中的23支肺静脉在窦性心律时记录到肺静脉电位,继续在窦性心律下消融,均完成电隔离;8支(10.5%)在房颤时未能完成电隔离的肺静脉,在窦性心律下成功隔离.手术时间4.2～7.6 h(平均5.3±3.7 h),平均X线曝光时间2.7 h,无栓塞、心包填塞及肺静脉狭窄等严重并发症.结论 (1)电生理指导下的肺静脉隔离治疗慢性房颤仍能达到较高的临床成功率.(2)电生理指导下的肺静脉隔离是安全可行的.(3)房颤过程中隔离的肺静脉仍需要在窦性心律下被重新证实.(4)在房颤过程中较难隔离的肺静脉可在转复窦性心律后进行隔离.     

最紊乱的心房颤动波在心房内分布特点及肺静脉隔离对其影响

目的针对心房颤动(房颤)基质消融是房颤消融的最终目标,最紊乱的房颤波(Ⅲ型房颤)所在部位可能为房颤维持的关键所在。本文分析Ⅲ型房颤波在双侧心房的分布特点及肺静脉隔离对其影响。方法11例持续性房颤患者,用普通的电生理检查导管或64极Basket导管分别在上腔静脉、右心房游离壁、右心房后壁、右心耳、右心房间隔部、左心房后壁、左心耳、肺静脉及冠状静脉窦记录2分钟房颤心内电图。根据Wells对房颤电活动的分类,人工计算Ⅲ型房颤占所记录的2分钟心电图的百分比(房颤紊乱指数,DI)。比较肺静脉隔离前及房颤自动终止或电复律前冠状窦口及冠状窦中、远端房颤紊乱指数的变化。肺静脉隔离在房颤中进行。在窦性心律下证实仍然存在心房—肺静脉间电活动传导,在窦性心律或心房刺激下完成肺静脉隔离。结果在所有720次采样中,房颤紊乱指数成双峰分布,第二峰起始点为75%。在左心房后壁(包括肺静脉)采样326次,房颤紊乱指数大于75%占22.4%,在间隔部(包括冠状静脉窦开口部)采样118次,房颤紊乱指数大于75%占37.3%,在心房其它部位(包括右心房游离壁、右心房后壁、上腔静脉、左心耳及冠状静脉窦左房部)采样276次,房颤紊乱指数大于75%占6.2%。左心房后壁及间隔部与心房其它部位比较有统计学差异(P<0.001)。肺静脉隔离导致了冠状静脉窦远端的房颤电活动变化(房颤紊乱指数消融前14.34±25.01,消融后4.62±8.64,P=0.016),而对冠状静脉窦口无明显影响(房颤紊乱指数消融前37.49±38.09,消融后46.83±41.96,P=0.243)。平均随访7个月,6例患者维持窦性心律,5例患者转为阵发性或持续性房颤。结论Ⅲ型房颤多集中在左心房后部,包括肺静脉。肺静脉隔离可降低Ⅲ型房颤在左心房的百分比,而对右心房影响较小。提示Ⅲ型房颤的集中部位可能为房颤维持的关键部位,肺静脉隔离可能改变了房颤维持的物质基础。     

肺静脉电隔离治疗持续性心房颤动方法学及效果评价

目的对肺静脉电隔离治疗持续性心房颤动(房颤)的方法学及效果进行评价。方法14例持续性房颤患者,房颤病史6个月～20年,房颤持续时间1周～4个月,左心房直径37～47 mm平均(40．8±26．0)mm,左心室射血分数0．26-0．68平均0．55±0．11。术前抗凝治疗2～3周。术中常规放置冠状静脉窦导管及右心室起搏导管。房间隔穿刺成功后送入肺静脉环状标测电极导管(Lasso电极导管)及盐水灌注消融导管,预设功率30 W,温度50℃,于肺静脉口依次对4根肺静脉进行隔离。电复律恢复窦性心律后,再将Lasso电极导管依次送入各肺静脉口部标测,在残存肺静脉电位(PVP)的部位继续消融至心房与肺静脉完全电隔离。结果共对54根肺静脉进行电隔离,左上肺静脉14根,左下肺静脉13根,右上肺静脉14根,右下肺静脉13根,电隔离成功后PVP均完全消失,即刻成功率100％,平均放电时间(2 972±843)s。1例出现心脏压塞。随访12-18个月,无房颤复发5例(36％);症状明显减轻、房颤发作频率及持续时间明显减少4例(28％);症状无改善,房颤仍持续发作5例(36％),总有效率64％。结论肺静脉电隔离对持续性房颤治疗有效,其方法学可行但存在一定局限性。     

联合应用磁共振扫描与三维电解剖标测系统图像融合技术及Lasso导管标测技术指导环肺静脉隔离治疗心房颤动

目的报道联合应用三维电解剖标测系统图像融合技术(Carto-Merge)及Lasso导管标测技术指导环肺静脉电隔离术治疗心房颤动(房颤)的结果。方法共入选56例症状明显、药物治疗无效的阵发性房颤患者,男性41例,女性15例,平均年龄58·5±12·7岁。应用Carto-Merge技术定位肺静脉口,之后环双侧肺静脉前庭线形消融左心房,终点为Lasso导管所标测的同侧肺静脉电位消失或肺静脉电位与心房电活动的分离。结果全组患者的电解剖标测点与影像图像(MRI)的空间差距均值1·79±0·33mm。首次手术的肺静脉隔离率为92·9%(52/56)。经随访18·3±5·7个月,有73·2%的患者(41/56)仍维持窦性心律。10例患者接受再次消融;经再次随访8·2±6·9个月,8位患者仍维持窦性心律。无一例患者出现肺静脉狭窄。结论联合应用Carto-Merge及Lasso导管标测技术,可有效地确保肺静脉的隔离,降低肺静脉狭窄等并发症的发生率。     

起源于肺静脉的阵发性房颤的电生理特点及射频消融治疗

目的探讨环状电极(Lasso电极)标测诱发阵发性房颤的肺静脉电位的电生理特点并对射频消融靶点进行评介。方法16例阵发性房颤者在Lasso电极标测寻找优势肺静脉电位(PVP),温控消融放电。结果起源于肺静脉的局灶性房颤其电生理特征包括:①异位激动灶主要分布于两上肺静脉。②肺静脉内可观察到从肺静脉内至心房传导阻滞。消融成功的靶点与体表心电图P′波提前(74±33)ms。成功隔离38条肺静脉:其中左上肺静脉16条,右上肺静脉12条。术程(186.7±63.8)min,X线曝光时间(51.5±15.0)min。术后随访1～12个月,11例(68.7%)无需药物而维持窦性心律。结论阵发性房颤异位起源点大多数位于左房肺静脉,起源于肺静脉的局灶性房颤有其特殊的电生理表现。     

Effectiveness of a handmade “New Carotid Catheter” in transradial carotid angiography: A comparison with conventional multipurpose catheters

Objective

The incidence and severity of carotid atherosclerosis increases in proportion with coronary artery disease and its severity. A special catheter specifically used for transradial carotid angiography has not yet been marketed. In this study, we investigate the feasibility and safety of our carotid catheter, which was made by reshaping currently available catheters.

Methods

Between 2010 and 2017, a total of 921 patients with indications for carotid angiography were identified after angiographic examinations and included in the study. Carotid angiography was performed in 403 patients (female, n = 161) using the 3.5 JL catheter, while in 518 (female, n = 207) patients, new catheters were employed. The new catheter was shaped like a hook in the laboratory with a heat gun. Demographic information and angiographic data from the patients in both groups were retrospectively analyzed.

Results

The baseline characteristics of both groups were comparable. When compared with the use of a 3.5 JL catheter, right transradial carotid angiographies performed with our new handmade catheter resulted in lesser amounts of opaque material used (55 mL vs 66 mL, P < 0.001) and shorter total fluoroscopy time, (3.60 ± 1.85 min vs 3.14 ± 1.55 min, P < 0.001). The handmade catheter also resulted in a higher success rate of selective visualization (97% vs 40%, P < 0.001). Rates of minor complication were comparable between the two catheters (6.5% vs 6.6% P = 234). Neither permanent damage nor morbidity or mortality was observed in either arm.

Discussion

Currently available catheters and methods are inadequate for routine transradial carotid angiography. For routine transradial carotid angiography, innovatively designed catheters are required. The catheter we developed for transradial carotid angiography was more successful than the conventional catheter in obtaining satisfactory images. High quality images can be obtained with the newly designed catheters.

Conclusion

Transradial carotid angiography can be performed using our newly developed carotid catheter. The carotid arteries of patients with widespread coronary artery disease can be visualized, while asymptomatic patients carrying a high risk of stroke can be treated, preventing potential stroke occurrence. In a larger‐scale comparative study, the favorable contributions of routine use of the new method and a decreased frequency of stroke may be demonstrated.     

POST INSERTION CATHETER CARE IN PERITONEAL DIALYSIS (PD) CENTRES ACROSS EUROPE. PART 2: COMPLICATION RATES AND INDIVIDUAL PATIENT OUTCOMES

The first part of this report, which looked at centre policy, showed that there was no consensus on the best way to manage a patient in the rest period between PD catheter insertion and the first use of the catheter for dialysis. This paper intends to investigate if the differences in policy had any effect on complication rate and individual patient outcomes. Data were included from 298 patients of 49 participating centres. The results revealed a high rate of catheter related complications, with half of the patients having been treated for complications including leakage (29%), malfunction (23%) or infection (10%), and a quarter of patients having been hospitalised for catheter problems. Leakage was more frequently observed in lean and obese patients and if the catheter was only immobilized for a short time period. Diabetes, having constipation at first use and having rested for less than 6 hours after catheter insertion were significant risk factors for malfunction. Infection seemed to be related to the type of catheter used and hygienic precautions (not significant) and showed a significant relationship with the frequency of dressing changes. There is still an important lack of evidence on which to develop an optimal protocol for PD catheter insertion and care before first use.     

Comparison of Ventricular Radiofrequency Lesions in Sheep Using Standard Irrigated Tip Catheter versus Catheter Ablation Enabling Direct Visualization

Comparison of Ventricular Radiofrequency Lesions in Sheep. Introduction: In vivo assessment of RF ablation lesions is limited. Improved feedback could affect procedural outcome. A novel catheter, IRIS? Cardiac Ablation Catheter (IRIS), enabling direct tissue visualization during ablation, was compared to a 3.5 mm open‐irrigated tip ThermoCool? Catheter (THERM) for endocardial ventricular RF ablation in sheep. Methods: Sixteen anesthetized sheep (6 ± 1 years old, 60 ± 10 kg) underwent ventricular RF applications with either the THERM (Biosense Webster) or IRIS (Voyage Medical) ablation catheter. In the THERM group, RF was delivered (30 W, 60 seconds) when electrode contact was achieved as assessed by recording high‐amplitude electrogram, tactile feedback, and x‐ray. In the IRIS group, direct visualization was used to confirm tissue contact and to guide energy delivery (10–25 W for 60 seconds) depending on visual feedback during lesion formation. Results: A total of 160 RF applications were delivered (80 with THERM; 80 with IRIS). Average power delivery was significantly higher in the THERM group than in the IRIS group (30 ± 2 W [25–30 W] for 57 ± 14 seconds vs 21 ± 4 W [10–25 W] for 57 ± 27 seconds; P<0.001). At necropsy, 62/80 (78%) lesions created with THERM were identified versus 79/80 (99%) with IRIS (P<0.001). The lesion dimensions were not significantly different between THERM and IRIS. Conclusion: Despite best efforts using standard clinical assessments of catheter contact, 22% of RF applications in the ventricles using a standard open‐irrigated catheter could not be identified on necropsy. In vivo assessment of catheter contact by direct visualization of the tissue undergoing RF ablation with the IRIS? catheter was more reliable by allowing creation of 99% prescribed target lesions without significant complications. (J Cardiovasc Electrophysiol, Vol. 23, pp. 869‐873, August 2012)     

Early Experience with a Computerized Robotically Controlled Catheter System

Background: Recently, the use of robotic assisted surgery has been utilized in cardiac surgical procedures. The use of robotics may offer benefits in precision, stability and control of instruments remotely. We report early experience with a novel remote robotic catheter control system (CCS).Methods: We used a computerized robotically controlled catheter system that enables the user to remotely manipulate the tip of a catheter precisely in three dimensions. We tested the robotic catheter control systems ability to navigate within the heart and to make precise, rapid and repeatable movements. We compared the CCS with the ability of a standard quadripolar steerable ablation catheter placed in a deflectable sheath to navigate and make precision movements. Twelve ex-vivo porcine hearts were utilized to permit accurate measurements of navigation and precision. Eight targets were selected for navigation and precision testing. Time was measured for the catheter to reach the predefined target from a specific starting point to test navigation. In addition, time was measured to contact a discrete 0.8 mm target in order to test precision.Results: The use of the CCS reduced the time needed for both navigation (8.5 ± 13.9 sec vs. 22.7 ± 26.7 sec, p = 0.002) and significantly decreased the time for precision targeting (10.1 ± 6.9 sec vs. 29.6 ± 26.4 sec, p < 0.001) in the specific RA and LA sites in the ex-vivo hearts.Conclusions: The use of a computerized robotically assisted catheter control system is feasible and shows promise in rapid precision movement of the catheter. Further study is needed to elucidate the role of such a system in-vivo and in patient specific catheter ablation and mapping.     

Balloon catheter systems for PTCA: The importance of the catheter length

The length of a balloon catheter system plays an important role in successfully dilating distal coronary or vein graft stenoses. We herein report a case in which a distal saphenous vein graft lesion could not be reached with a conventional balloon catheter. Factors responsible for this failure included insufficient length. The lesion was eventually reached and successfully dilated with another balloon catheter, which according to the manufacturer had the same length as the first balloon. In order to study this phenomenon eleven balloon catheters were examined using the following measurements: functional catheter length, deliverable catheter length, crossing distance and longitudinal compression. Seven guide catheters were also measured. Results showed variations in standard functional length between several manufacturers, ranging from 132.2–137.8 cm. The deliverable length ranged from 18.3–23.9 cm, crossing distance ranged from 7–37 mm, and the longitudinal compression ranged from 4–30 mm. Guiding catheter length varied among several manufacturers, ranging from 100.6–107 cm. A significant variation was found not only among certain manufacturers, but also among several standard catheters made by one manufacturer. The results of this study suggest that significant variations exist in the length of standard balloon catheters and guiding catheters even among those made by the same manufacturer. These findings can affect the ability to reach a lesion and should be taken into account, especially when attempting to perform angioplasty of stenoses located in the distal portion of a coronary artery or saphenous vein graft.     

Antibiotic lock therapy for salvage of tunneled central venous catheters with catheter colonization and catheter‐related bloodstream infection

Central venous catheters (CVCs) represent a significant source of infection in patients undergoing hematopoietic stem cell transplantation and can add to the cost of care, morbidity, and mortality. Organisms forming biofilms on the inner surface of catheters require a much higher local antibiotic concentration to clear the pathogen growth. Antibiotic lock therapy (ALT) represents one such strategy to achieve such high intraluminal concentrations of antibiotics and can facilitate catheter salvage. Patients with catheter colonization (CC) or hemodynamically stable catheter‐related bloodstream infection (CRBSI) received ALT per institutional policy. We analyzed the incidence of CC and CRBSI and salvage rate of tunneled CVCs (Hickman) with ALT in patients undergoing hematopoietic stem cell transplant in this retrospective study. Catheter colonization was noted in 9.8% and CRBSI in 10.7% patients. Gram‐negative bacilli (GNB) accounted for 45% and 83% of isolates in CC and CRBSI, respectively. In patients with CRBSI, the rate of catheter salvage with the use of ALT in addition to systemic antibiotics was 86% compared to 55% in patients with systemic antibiotics use only (P = 0.06). There was no CRBSI related mortality, and no increase in resistant strains was noted at subsequent CRBSI. In conclusion, ALT represents an important strategy for catheter salvage, especially for gram‐negative infections, in a carefully selected patient population.     

Electroanatomic Magnetic Mapping during Ablation of Isthmus-dependent Atrial Flutter

Introduction: Although recent studies have demonstrated that the endpoint of isthmus conduction block is superior to that of termination and subsequent inability to induce atrial flutter (AFl), the optimal method for determining isthmus conduction block has not been determined. Electroanatomic magnetic mapping during coronary sinus (CS) pacing may provide a reliable endpoint for AFl ablation. Methods and Results: Catheter mapping and ablation was performed in 42 patients with isthmus-dependent AFl. The patients were divided into two groups, based on procedural endpoint: Group I (28 patients) – isthmus conduction block was determined based on multipolar catheter recordings and electroanatomic mapping, and Group II (14 patients) – isthmus conduction block was determined by electroanatomic mapping during CS pacing alone. In Group I, ablation procedures were acutely successful in 25 of 28 patients (89±%). A 100±% concordance between the data presented by multipolar catheter recordings and electroanatomic mapping was noted in determining the presence or absence of isthmus conduction block. In Group II, ablation procedures were acutely successful in 13 of 14 patients, 13 (93±%). After a mean of 16.3±3.7 months follow up, there was 1 atrial flutter recurrence in the 38 patients (2.6±%) with demonstrated isthmus block at the end of the procedure. Conclusions: Electroanatomic magnetic mapping during CS pacing is comparable to the multipolar catheter mapping technique for assessing isthmus conduction block as an endpoint for AFl ablation procedures.     

GOLDART--Gold Alloy Versus Platinum-Iridium Electrode for Ablation of AVNRT

Introduction: Radiofrequency (RF) catheter ablation targeting the slow pathway is currently the most effective treatment for patients with atrioventricular nodal reciprocating tachycardia (AVNRT). Gold exhibits a more than four times greater thermal conductivity than platinum, and the creation of deeper lesions was demonstrated in ex vivo animal experiments. The current clinical trial was initiated to compare gold catheters with standard platinum–iridium (Pt–Ir) material and to analyze differences in the increase of power or temperature as a function of time during RF ablation.
Methods: A prospective, randomized multicenter study design was used to compare RF deliveries at the slow pathway with standard Pt–Ir tip catheters (128 patients), as well as gold alloy tip electrodes (124 patients) during AVNRT ablation.
Results: Although there was a trend towards higher power delivery in the gold group (4.96 vs. 4.28 W/s), this trend was not statistically significant. Likewise, cumulative duration of all RF ablations, total procedure time, and power delivered at other time points were not significantly different between the groups. Also, the occurrence of AV-block and sensations of pain were similar in both treatment groups. However, charring on the catheter tip after the intervention was observed eightfold more frequently in the Pt–Ir group.
Conclusion: In conclusion, power delivery cannot be significantly increased by RF ablation of AVNRT with gold electrodes. But the electrode material seems to be safe and well-tolerated and specifically did not increase the risk of AV-block. The significant reduction of coagulum formation on gold tips suggests a possible advantage of this material beyond its better conduction properties.