Efficacy and safety of segmental ostial versus circumferential extra-ostial pulmonary vein isolation for atrial fibrillation

INTRODUCTION: Pulmonary vein (PV) isolation for atrial fibrillation (AF) can be performed using a segmental ostial or a circumferential extra-ostial approach. The relative merits and potential limitations of each approach are currently debated. Here we report our early experience with each of these approaches, including their relative efficacy and safety. METHODS AND RESULTS: Forty patients with drug-refractory AF underwent segmental ostial PV isolation and were compared to 40 consecutive patients who underwent PV isolation using a circumferential extra-ostial approach. The latter approach described here is novel in two aspects: (1) the endpoint for ablation was PV isolation and not only delay in left atrial to PV conduction time, and (2) isolation of the right and left PVs was achieved by a single encirclement of ipsilateral veins. At follow-up, 60% of the patients in the segmental group were free of AF compared to 75% of the patients in the circumferential group. There was one thromboembolic cerebrovascular complication during the ablation procedure in each group. CONCLUSION: PV isolation using a circumferential extra-ostial approach, where the ipsilateral PVs are isolated together by one encircling line of block using electroanatomic mapping, is a technically feasible procedure. This approach is at least as effective and safe as the more established segmental ostial approach for AF ablation.     

Phased-array intracardiac echocardiography during pulmonary vein isolation and linear ablation for atrial fibrillation

INTRODUCTION: Fluoroscopic imaging provides limited anatomic guidance for left atrial structures. The aim of this study was to determine the utility of real-time, phased-array intracardiac echocardiography during radiofrequency ablation for atrial fibrillation. METHODS AND RESULTS: In 29 patients undergoing pulmonary vein isolation (n = 16) or linear (n = 13) left atrial radiofrequency ablation for atrial fibrillation, intracardiac phased-array echocardiography was used to visualize left atrial anatomy and the pulmonary veins, as well as ablation and mapping catheters during ablation procedures. In the 16 pulmonary vein isolation patients, the mean pulmonary vein ostial diameters measured by venography and intracardiac echocardiography were similar for all veins positions, except that left common pulmonary vein diameters were larger as measured by echocardiography (2.50 +/- 0.29 cm) than by venography (1.79 +/- 0.50 cm, P = 0.001). The ostial diameters measured by echocardiography and venography were not correlated, however (r = 0.23, P = 0.19). As directed by echocardiography, only 1 of 25 circular mapping catheters (4%) used in 16 patients was replaced due to inappropriate sizing of the pulmonary veins. Mean pulmonary vein Doppler flow velocities increased after ablation for left-sided veins but ostial diameters were unchanged. In the linear ablation patients, the entire extent of the linear electrode array could be visualized in only 3 of 52 of catheter positions (6%) in the 13 patients. A portion of the catheter could be seen in only 50% of all target catheter positions. CONCLUSION: Phased-array intracardiac echocardiography (1) allows sizing and positioning of pulmonary vein mapping catheters, (2) provides measures of pulmonary vein ostial diameters, (3) continuously monitors pulmonary vein Doppler flow velocities, and (4) has limited use in positioning linear ablation catheters in the left atrium.     

Incidence of pulmonary vein stenosis 2 years after radiofrequency catheter ablation of refractory atrial fibrillation.

AIMS: Pulmonary vein ablation offers the potential to cure patients with atrial fibrillation. In this study, we investigated the incidence of pulmonary vein stenosis after radiofrequency catheter ablation of refractory atrial fibrillation by systematic long-term follow-up. METHODS AND RESULTS: Forty-seven patients with refractory and highly symptomatic atrial fibrillation underwent radiofrequency catheter ablation of arrhythmogenic triggers inside the pulmonary veins and/or ostial pulmonary vein isolation with conventional mapping and ablation technology. These patients had follow-up examinations at 2 years with transoesophageal doppler-echo and/or angio magnetic resonance imaging for the evaluation of the pulmonary veins. Seventy-seven percent of the patients were free from atrial fibrillation, 51% were without antiarrhythmic drugs, and 26% were on previously ineffective antiarrhythmic drug therapy. However, 13 of the 47 patients showed significant pulmonary vein stenosis or occlusion. Only three of these 13 patients complained of dyspnoea. Distal ablations inside the pulmonary vein were associated with a 5.6-fold higher risk of stenosis than ostial ablations. CONCLUSIONS: At 2-year follow-up, the risk of significant pulmonary vein stenosis/occlusion after radiofrequency catheter ablation of refractory atrial fibrillation with conventional mapping and ablation technology was 28%. Distal ablations inside smaller pulmonary veins should be avoided because of the higher risk of stenosis than ablation at the ostium.     

Multimodality imaging to diagnose pulmonary vein stenosis following atrial fibrillation ablation

BACKGROUND: Atrial fibrillation (AF) is increasing in prevalence. Although experienced centers performing radiofrequency pulmonary vein isolation procedures have reported success rates approaching 72%, in rare instances it is complicated by stenosis of one or more pulmonary veins. In this report we present a case of recurrent pulmonary vein stenosis (PVS) following radiofrequency ablation for AF.     

阵发性心房颤动局灶消融后复发病例的大静脉肌袖电隔离治疗

对肺静脉内点消融治疗术后随访 2 2± 1 1 .1个月内的心房颤动 (简称房颤 )复发病例 ,在Lasso标测导管指引下 ,进行再次心内电生理检查及大静脉肌袖电隔离治疗。探讨点消融治疗阵发性房颤后复发的机制 ,并对再次经验性大静脉肌袖电隔离治疗的结果进行分析与评价。 5例患者共接受心内电生理标测和电隔离治疗 6次 (一例行第二次电隔离 ) ,除一例行右下肺静脉靶肌袖的电隔离外 ,其余病例均进行了经验性全部大静脉的电隔离 ,共电隔离心脏大静脉 1 5根 ,其中肺静脉 1 3根、上腔静脉 2根 ,即刻电隔离成功率 1 0 0 %。术后随访 1 1 .8± 8.9个月 ,均无房颤复发。因此 ,对于阵发性房颤导管射频点消融后复发病例进行经验性全部大静脉肌袖电隔离治疗可以满意控制房颤的发作。     

Randomized comparison of bipolar versus unipolar plus bipolar recordings during segmental ostial ablation of pulmonary veins

INTRODUCTION: Segmental ostial ablation to isolate pulmonary veins is guided by pulmonary vein potentials. The aim of this prospective randomized study was to compare the utility of unipolar plus bipolar electrograms versus only bipolar electrograms as a guide for segmental ablation to isolate the pulmonary veins in patients with atrial fibrillation. METHODS AND RESULTS: Isolation of the left superior, right superior, and left inferior pulmonary veins was attempted in 44 patients (35 men and 9 women; mean age 54 +/- 10 years) with paroxysmal atrial fibrillation. A decapolar Lasso catheter was positioned in the pulmonary veins, near the ostium, and a conventional ablation catheter was used for segmental ablation aimed at elimination of all pulmonary vein potentials. One hundred fourteen pulmonary veins were randomly assigned for ostial ablation guided by either bipolar or unipolar plus bipolar recordings. Electrical isolation was achieved in 51 (96%) of 53 pulmonary veins randomized to the bipolar approach, and 57 (93%) of 61 pulmonary veins randomized to the unipolar plus bipolar approach (P = 0.7). In the unipolar plus bipolar group, the total duration of radiofrequency energy needed to achieve isolation, 5.5 +/- 2.8 minutes/vein, was significant shorter than in the bipolar group, 7.6 +/- 4.1 minutes/vein (P < 0.01). Mean procedure and fluoroscopy durations per vein were 19% to 28% shorter in the unipolar plus bipolar group. CONCLUSION: Segmental ostial ablation to isolate the pulmonary veins can be achieved more efficiently and with less radiofrequency energy when guided by both unipolar and bipolar recordings than by bipolar recordings alone.     

环单侧靶肺静脉-前庭射频消融治疗心房颤动

目的 Carto系统指导下对心房颤动（房颤）相关的靶肺静脉进行环同侧上、下肺静脉-前庭单环线性消融隔离,观察疗效.方法 对25例术中反复自发肺静脉相关房性早搏（房早）,并触发房性心动过速（房速）和/或房颤的患者,在Carto系统结合单Lasso环状标测导管指导下进行环靶肺静脉-前庭单环射频消融术,达到肺静脉隔离.结果 消融过程中25例患者房早、房速、房颤终止,其中19例患者有自发的肺静脉电位,15例慢于窦性心率.4例患者隔离后肺静脉内发生房颤或房速,2例在肺静脉内补点消融后肺静脉电位消失.随访（22.24±9.01）个月,23例无房速、房颤发作,2例患者术后复发房颤,1例接受再次手术,术后房颤发作减少,1例口服胺碘酮控制.结论 术中能够明确靶肺静脉、单个触发灶的房颤患者,在Carto系统结合单Lasso导管指导下行单环线性消融隔离治疗房颤,成功率高、复发率低,可减少手术损伤.     

The role of posterior wall isolation in catheter ablation of persistent atrial fibrillation

The left atrial posterior wall has many embryologic, anatomic, and electrophysiologic characteristics, that are important for the initiation and maintenance of persistent atrial fibrillation. The left atrial posterior wall is a potential target for ablation in patients with persistent atrial fibrillation, a population in whom pulmonary vein isolation alone has resulted in unsatisfactory recurrence rates. Published clinical studies report conflicting results on the safety and efficacy of posterior wall isolation. Emerging technologies including optimized use of radiofrequency ablation, pulse field ablation, and combined endocardial/epicardial ablation may optimize approaches to posterior wall isolation and reduce the risk of injury to nearby structures such as the esophagus. Critical evaluation of future and ongoing clinical studies of posterior wall isolation requires careful scrutiny of many characteristics, including intraprocedural definition of posterior wall isolation, concomitant extrapulmonary vein ablation, and study endpoints.     

射频消融治疗起源于肺静脉的房性心律失常的临床疗效评价

评价射频消融 1 4例起源于肺静脉的房性早搏 (简称房早 )或房性心动过速 (简称房速 )的临床疗效。 1 4例患者因频发房早 (6例 )和房速 (8例 )而接受肺静脉消融治疗。经房间隔穿刺肺静脉造影确定肺静脉口部及近端 ,大头电极或环状电极标测左房和肺静脉 ,以心律失常的异常电活动最早起源为靶肺静脉和消融靶点 ,消融后房早消失或房速终止且不再诱发和自发为消融终点。结果 :1 4例心律失常起源于右上 (8例 )、左上 (5例 )和左下 (1例 )肺静脉近端 ,1 0例在异常电活动最早部位行局灶点消融达到手术终点 ,4例患者在靶肺静脉口部行多点电隔离消融达手术终点。随访 4～ 2 7个月 ,1例心律失常复发。结论 :射频消融治疗肺静脉口部及近端的房早和房速具有良好的临床疗效     

Minimally invasive off-pump pulmonary vein isolation to treat paroxysmal atrial fibrillation

BACKGROUND: Minimally invasive off-pump pulmonary vein isolation to cure paroxysmal atrial fibrillation (PAF) may be an alternative to percutaneous catheter-based procedures. METHODS: Three patients with highly symptomatic lone PAF refractory to medical treatment and having undergone unsuccessful catheter-based ablation underwent pulmonary vein isolation using the Cardioblate BP device with a minimally invasive approach. RESULTS: There were no complications and all patients were discharged in sinus rhythm. Mean ablation time per lesion was 15.2 sec and mean operation time was 118 min. CONCLUSIONS: Irrigated bipolar radiofrequency ablation of the pulmonary veins is safe and can be performed off-pump in a minimally invasive manner.     

Comparison of atrial fibrillation ablation using cryoballoon versus radiofrequency in patients with left common pulmonary veins: mid-term follow-up results

Journal of Interventional Cardiac Electrophysiology - Cryoballoon (CB) and radiofrequency (RF) ablation techniques have similar outcomes for pulmonary vein isolation (PVI) in patients with atrial...     

Catheter ablation of atrial fibrillation: Radiofrequency catheter ablation for redo procedures after cryoablation

AIM: To evaluate the effectiveness of two different strategies using radiofrequency catheter ablation for redo procedures after cryoablation of atrial fibrillation.METHODS: Thirty patients(paroxysmal atrial fibrillation: 22 patients,persistent atrial fibrillation: 8 patients) had to undergo a redo procedure after initially successful circumferential pulmonary vein(PV) isolation with the cryoballoon technique(Arctic Front Balloon,CryoCath Technologies/Medtronic).The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy(CARTO;Biosense Webster) depending on the intra-procedural findings.After discharge,patients were scheduled for repeated visits at the arrhythmia clinic.A 7-day Holter monitoring was performed at 3,12 and 24 mo after the ablation procedure.RESULTS: During the redo procedure,a mean number of 2.9 re-conducting pulmonary veins(SD ± 1.0 PVs) were detected(using a circular mapping catheter).In 20 patients,a segmental approach was sufficient to eliminate the residual pulmonary vein conduction because there were only a few recovered pulmonary vein fibres.In the remaining 10 patients,a circumferential ablation strategy was used because of a complete recovery of the PV-LA conduction.All recovered pulmonary veins could be isolated successfully again.At 2-year follow-up,73.3% of all patients were free from an arrhythmia recurrence(22/30).There were no major complications.CONCLUSION: In patients with an initial circumferential pulmonary vein isolation using the cryoballoon technique,a repeat ablation procedure can be performed safely and effectively using radiofrequency catheter ablation.     

三维影像融合技术指引导管消融治疗心房颤动

目的 探索三维影像融合技术指引导管消融治疗心房颤动的意义。方法 入选66例房颤患者,随机分为两组,Carto组(32例)和Carto-Merge组(34例),分别在单独Carto三维标测和Carto-Merge融合CT影像指导下行环肺静脉前庭线性消融,持续性房颤和持久性房颤附加行左房顶部、二尖瓣峡部线和右房三尖瓣峡部线消融,消融终点为环肺静脉彻底隔离,消融线双向阻滞,术后随访18个月。对比两组手术操作时间、射频消融时间、X线曝光时间、手术并发症及随访成功率和房性心律失常复发构成比的差异。结果 ①两组患者基线资料无明显差异(P>0.05);②Carto-Merge组肺静脉即时隔离率高于Carto组,平均手术操作、射频消融、X线曝光时间及并发症发生率均低于Carto组(P<0.05);③随访完成后,两组射频消融成功率、复发房性心律失常构成类型比较无明显差异(P>0.05)。结论 三维电解剖标测合并CT影像融合在保证房颤射频消融成功率的前提下,提高了手术效率,降低手术并发症,减少X线曝光,尤其对初期开展房颤消融工作度过学习曲线大有帮助,值得临床射频电生理手术尝试应用。     

入心静脉口环状超声消融动物实验

观察入心静脉口环状超声消融对心电传导及影像学的影响 ,探讨超声消融在治疗局灶源性心房颤动 (简称房颤 )中的临床价值。选用健康成年杂种犬 7只 ,用特制的超声球囊导管和温控大头导管在S1S1快速刺激下分别环状消融肺静脉口和上、下腔静脉口。超声消融时预设温度 60℃、功率 2 0W、脉宽 15ms,3 0 %输出方式 ;若放电 10s后温度达不到 5 0℃ ,则加大功率、脉宽或输出方式 ,直至达到有效消融温度 ( 5 5℃以上并持续 3 0s以上 ) ;观察消融前后心电传导的变化及管腔形态的变化。结果 :共超声消融入心静脉口 10个 ,除一个上腔静脉口因管腔直径过大只在放电时引起一过性电隔离外 ,其余 9个超声消融后都可造成持久的电隔离 ,且未见急性狭窄 ;而 7个射频消融的入心静脉口无一例形成持久的电隔离 ,且有 4例发生急性狭窄。结论 :超声消融更易在入心静脉口形成完全、持久的电隔离 ,很少导致管腔狭窄 ,且操作简单 ,安全可靠 ,优于射频消融。     

Left atrial ablation for atrial fibrillation: creating the "box lesion" with a bipolar radiofrequency device

The maze procedure is the gold standard for the ablation of atrial fibrillation, and the "box lesion" around the pulmonary veins is the most important part of this procedure. We have created this lesion with a bipolar radiofrequency ablator, abandoning the usual use of this device (to achieve bilateral epicardial isolation of the pulmonary veins).From March 2004 through the end of May 2010, we performed surgical ablation of atrial fibrillation in 240 patients. Of this number, 205 underwent operation by a hybrid maze technique and the remaining 35 (our study cohort) underwent the creation of a box lesion around the pulmonary veins by means of a bipolar radiofrequency device. Ablation lines were created by connecting the left atriotomy to the amputated left atrial appendage, with 2 ablation lines made with a bipolar radiofrequency device above and below the pulmonary veins. Lesions were made along the transverse and oblique sinuses by epicardial and endocardial application of a bipolar device. The left atrial isthmus was ablated by bipolar radiofrequency and cryoprobe. No complications were associated with the box lesion: 90% and 89% of patients were in sinus rhythm at 3 and 6 months of follow-up, respectively.By creating a box lesion around the pulmonary veins, we expect to improve transmurality by means of epicardial and endocardial ablation of 1 rather than 2 layers of atrial wall, as in epicardial pulmonary vein isolation. Isolation of the entire posterior wall of the left atrium is better electrophysiologically and renders dissection around the pulmonary veins unnecessary.     

Focal Atrial Tachycardia Originating from the Right Atrial Appendage: First Successful Cryoballoon Isolation

Electrical Isolation of the Right Atrial Appendage Using the Cryoballoon. Focal atrial tachycardias (AT) can arise from the right atrial appendage (RAA). However, conventional catheter mapping and radiofrequency (RF) ablation inside the RAA is associated with the risk of cardiac perforation. The cryoballoon catheter represents a novel ablation device that was originally developed to facilitate pulmonary vein isolation. This report describes the first successful RAA isolation using a cryoballoon in a patient with an incessant focal RAA AT despite previous irrigated tip endo- and epicardial ablation attempts. Further, cryoballoon ablation targets beyond pulmonary veins may evolve.     

Effects of operator experience on the outcome and duration of pulmonary vein isolation procedures for atrial fibrillation

Segmental, ostial ablation to isolate the pulmonary veins has been shown to be effective for the treatment of atrial fibrillation (AF). The purpose of this study was to determine the effects of operator experience on the outcome and duration of pulmonary vein isolation procedures for AF. One hundred three consecutive patients with AF underwent segmental, ostial ablation to isolate pulmonary veins. The effect of operator experience on the outcome and duration of the procedure was measured. The mean procedure duration was 232 +/- 70 minutes (range 50 to 460). There was an indirect linear relation between the total procedure time and the number of procedures performed (r = -0.68; p <0.001), and between the total fluoroscopic time and the number of procedures performed (r = -0.71; p <0.001). The percentage of patients in whom complete isolation of the pulmonary veins was achieved and the total duration of radiofrequency energy delivered during the procedures remained stable as operator experience increased. Operator experience was not an independent predictor of recurrent AF. The primary effect of operator experience on pulmonary vein isolation procedures for AF was a marked reduction in the duration of the procedure and fluoroscopic time. Long procedure durations and large amounts of radiation exposure may currently limit the widespread application of this therapy. The results of this study suggest that after >75 cases, segmental ablation to isolate the pulmonary veins using fluoroscopy and conventional radiofrequency ablation usually is feasible in <3 hours.     

Conventional pulmonary vein isolation compared with the “box isolation” method: a randomized clinical trial

Purpose  

Esophageal injury is a potential complication with radiofrequency ablation in the posterior wall of the left atrium (LA). The “box isolation” method isolates the posterior LA wall including the pulmonary veins without ablation on the posterior LA wall. This study compares the acute and long-term efficacy of the box isolation method with conventional circumferential pulmonary vein isolation (PVI) for catheter ablation of AF.     

Epicardial Connections Between the Pulmonary Veins and Left Atrium: Relevance for Atrial Fibrillation Ablation

Epicardial Connections Between PVs and the LA. Introduction: Some observations support the existence of epicardial connections (ECs) between ipsilateral pulmonary veins (vein to vein ECs [VVECs]), and we have observed venoatrial ECs inserted at distance from the pulmonary vein ostium (vein to atrium ECs [VAECs]). Our aim was to determine the prevalence of ECs and their relevance for pulmonary vein isolation. Methods and Results: We studied 100 consecutive patients with drug‐refractory atrial fibrillation who underwent ostial pulmonary vein isolation by cooled radiofrequency catheter ablation. A VVEC was identified if pulmonary vein pacing activated the ipsilateral vein before the atrium, requiring ablation of both venous ostia to isolate either pulmonary vein. A VAEC was identified if pacing produced atrial breakthrough located at distance from the venous ostium, requiring extraostial ablation to isolate the pulmonary vein. Patients with ECs (20%) were younger (P = 0.02) and had a higher prevalence of structural heart disease (P = 0.01) than patients without ECs. VVECs and VAECs were identified in 32 pulmonary veins (10%) and VAECs in 10 veins (3%). Veins with ECs had a higher rate of early recurrence of conduction following isolation (29% vs 11%; P = 0.01). Conclusion: Twenty percent of patients with atrial fibrillation had ECs resistant to ostial ablation in one or more pulmonary veins. Isolating veins with ECs may require a different ablation approach. These connections are associated with an increased rate of early recurrence of conduction . (J Cardiovasc Electrophysiol, Vol. 22, pp. 149‐159, February 2011)