How to perform posterior wall isolation in catheter ablation for atrial fibrillation

Catheter ablation has become standard of care in patients with symptomatic atrial fibrillation (AF). Although there have been significant advances in our understanding and technology, a substantial proportion of patients have ongoing AF requiring repeat procedures. Pulmonary vein isolation (PVI) is the cornerstone of AF ablation; however, it is less effective in patients with persistent as opposed to paroxysmal atrial fibrillation. Left atrial posterior wall isolation (PWI) is commonly performed as an adjunct to PVI in patients with persistent AF with nonrandomized studies showing improved outcomes. Anatomical considerations and detailed outline of the various approaches and techniques to performing PWI are detailed, and advantages and pitfalls to assist the clinical electrophysiologist successfully and safely complete PWI are described.     

Persistent Atrial Fibrillation Ablation: Where Do We Go From Here?

Catheter ablation is being used increasingly for the treatment of atrial fibrillation (AF). Pulmonary vein antral isolation is considered the "cornerstone" for the ablation of AF. This approach has demonstrated consistent rates of success for paroxysmal AF, but the rates of success for persistent AF are lower. There has long been a hypothesis that additional ablation beyond pulmonary vein isolation is required to achieve better outcomes in the population with persistent AF. However, large clinical trials have demonstrated recently that such approaches as empiric linear ablation and/or ablation of complex fractionated electrograms may add no benefit over pulmonary vein isolation alone in persistent AF. Furthermore, new technologies are improving the durability and outcome of pulmonary vein isolation alone. These observations have endorsed a search for new potential targets for adjuvant ablation, which currently include ablation of dynamic phenomena during AF such as rotational and focal activations, ablation of scar regions in the atria, isolation of the left atrial posterior wall, and ablation of nonpulmonary vein triggers. Whether any of these additional approaches will add to the success of ablation for persistent AF is unknown. Smaller study results are mixed. Only the performance of large-scale randomized trials will definitively answer whether additional ablation over pulmonary vein isolation alone with improve outcomes for persistent AF.     

Atrial Fibrillation Ablation Using Vein of Marshall Ethanol Infusion

Catheter ablation has become a cornerstone treatment for atrial fibrillation (AF). Pulmonary vein isolation is the accepted approach for paroxysmal AF ablation, but it is less effective for persistent AF. The vein of Marshall (VOM) is located in the epicardial left atrium and can be a source of AF triggers as well as a tract for autonomic nerves. It directly communicates with the underlying myocardium, including the left atrial ridge and the posterior mitral isthmus. This review discusses the latest evidence regarding the mechanisms, procedural aspects, and outcomes of VOM ethanol infusion when used as an adjunct to pulmonary vein isolation in patients with persistent AF.     

Our approach to persistent atrial fibrillation in the setting of pulmonary vein isolation

In patients with persistent atrial fibrillation (AF) despite durable pulmonary vein isolation, there are a variety of approaches to further ablation. Here we summarize our strategy in this population. In brief, our approach is to isolate the posterior wall, ablate the coronary sinus musculature and left lateral ridge, complete a lateral mitral line, and achieve cavotricuspid isthmus block. Subsequently, we target organized atrial flutters and if AF persists, we ablate areas of long, fractionated electrograms within scarred regions. We administer isuprel in patients with a presentation consistent with triggered atrial fibrillation (low scar burden, paroxysms of AF).     

Approach to repeat ablation of atrial fibrillation when the pulmonary veins are already isolated

In this article, we summarize our approach to a repeat ablation for persistent atrial fibrillation when the pulmonary veins are already isolated. We summarize the approach to posterior wall isolation, ablation of drivers of atrial fibrillation, and also ablation of incompletely ablated regions identified during sinus rhythm.     

Catheter ablation of atrial fibrillation. -State of the Art-

Atrial fibrillation (AF) is an arrhythmia associated with increased morbidity and mortality. Since the first report of catheter ablation curing AF, numerous techniques have evolved, from linear ablation to segmental pulmonary vein (PV) isolation, to extensive encircling PV isolation, to left atrial (LA) linear ablation, to ablation of complex fragmented atrial electrograms (CFAEs) and ablation of ganglionated plexi. A new approach for complete isolation of the posterior LA, including all PVs, is box isolation. PV isolation is associated with a high clinical success rate in paroxysmal AF. However, in persistent AF or longstanding persistent AF, PV isolation only may not be sufficient, so additional ablation at sites with CFAEs is needed to improve the clinical outcome. A hybrid approach of combining PV isolation plus CFAE ablation is highly effective in the majority of patients with persistent AF or longstanding persistent AF. Thus, AF ablation is an effective and established treatment for AF that offers an excellent chance of a lasting cure. It is about time that AF ablation became a first-line therapy for selected patients with AF.     

Prevention of esophageal thermal injury during radiofrequency ablation for atrial fibrillation

Pulmonary vein isolation using radiofrequency ablation is an effective therapy in patients with atrial fibrillation. However, the esophagus descends in close proximity to the posterior wall of the left atrium and renders this structure susceptible to thermal injury. Esophageal ulceration has been hypothesized to be a precursor to left atrial-esophageal fistula, a procedural complication associated with poor prognosis. In this review, we have analyzed and summarized the published data regarding esophageal thermal injury during catheter ablation for atrial fibrillation and strategies to minimize risk of this complication. While esophageal temperature monitoring can be useful, multiple factors such as patient characteristics and specific strategies for radiofrequency energy delivery also merit consideration.     

Ganglionated plexi as neuromodulation targets for atrial fibrillation

The autonomic nervous system plays an important role in the genesis of atrial fibrillation and is one of the candidate targets for atrial fibrillation therapy. This review focuses on the role of the autonomic nervous system in atrial fibrillation development and discusses the results of the ganglionated plexi catheter and surgical ablation in preclinical and clinical studies. The heart is innervated by the extrinsic and intrinsic autonomic nervous systems. The intrinsic autonomic nervous system consists of multiple ganglionated plexi and axons, which innervate the neighboring atrial myocardium and control their electrophysiological properties. Abnormal autonomic innervation has been observed in an animal model of atrial fibrillation and in humans. Direct recordings of autonomic nerve activity in canine models showed that atrial tachyarrhythmia episodes were invariably preceded by intrinsic cardiac autonomic nerve activity, thus supporting the importance of intrinsic cardiac autonomic nerve activity as the triggers for atrial tachyarrhythmia. Targeting ganglionated plexi with catheter ablation improves the outcomes of paroxysmal atrial fibrillation ablation in addition to pulmonary vein antrum isolation. Ablation of ganglionated plexi alone without pulmonary vein isolation is also useful in controlling paroxysmal atrial fibrillation in some patients. However, surgical ganglionated plexi ablation in patients with a large left atrium, persistent atrial fibrillation, and/or a history of prior catheter ablation does not result in additional benefits. These different outcomes suggest that ganglionated plexi ablation is effective in managing patients with paroxysmal atrial fibrillation, but its effects in patients with persistent atrial fibrillation and advanced atrial diseases might be limited.     

关于心房颤动导管消融治疗方法学的思考

现阶段心房颤动导管消融治疗的方法学主要包括以下四种:⑴肺静脉节段性电学隔离;⑵环肺静脉左心房线性消融;⑶超声引导下的近肺静脉开口部心房环状消融;⑷三维标测 双肺静脉环状标测电极导管指导下的环肺静脉射频消融电隔离。现对这4种消融方法的有效性、存在问题及理论意义等进行了论述。     

干预自主神经对心房颤动影响的研究进展

心房颤动是临床中常见的快速型心律失常.阵发性心房颤动的病理生理机制相对单一,消融术式首选肺静脉电隔离术,临床疗效满意.相比之下,持续性心房颤动的发生机制较为复杂,消融术式百花齐放:肺静脉电隔离术及其基础上的复合术式、肾去交感化、复杂心房碎裂电位消融及神经节消融等.大量动物实验及临床研究证实自主神经与心房颤动的发生及维持...     

左心耳电隔离在持续性心房颤动治疗中的研究进展

肺静脉隔离是心房颤动(房颤)导管消融的基石,对于阵发性房颤有良好效果,但在持续性房颤中的效果则不尽人意.肺静脉隔离以外的辅助消融策略有助于提高持续性房颤的手术成功率.左心耳不仅是心腔内血栓的常见起源,还是导致快速性房性心律失常发生或维持的因素,因而左心耳电隔离成为持续性房颤辅助消融策略之一,研究表明其可能有助于提高持续...     

Left atrial-esophageal fistula following radiofrequency catheter ablation of atrial fibrillation

This report describes a fatal case of left atrial-esophageal fistula occurring in a 72-year-old man after a radiofrequency catheter ablation of paroxysmal atrial fibrillation. Catheter ablation was performed around the pulmonary vein using an 8-mm-tip electrode (60 W or 55 degrees C) guided by a 25-mm circular catheter. On day 22 of follow-up, the patient presented with seizures followed by hematemesis due to left atrial-esophageal fistula. His clinical condition deteriorated, and he died of speticemia. Thus, left atrial-esophageal fistula is a sever complication of radiofrequency catheter ablation of the left atrial posterior wall.     

Is pulmonary vein isolation enough for persistent atrial fibrillation?

Pulmonary vein isolation (PVI) is a well‐established treatment for atrial fibrillation (AF); however, studies report suboptimal outcomes in persistent AF. Adjuvant ablation targeting the substrate outside the pulmonary veins has been proposed to improve the success rates of the procedure. In this review, we summarize the current evidence regarding additional ablation over PVI in persistent AF. We describe the different approaches for adjuvant ablation, outcomes, and future perspectives.     

Catheter ablation of persistent atrial fibrillation: anatomically based circumferential pulmonary vein ablation in combination with a potential-guided segmental approach to achieve complete pulmonary vein isolation

Background  

Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. However, catheter ablation of persistent atrial fibrillation is still a challenge. Various rather complex ablation strategies exist and their results are not very favorable. Therefore, the aim of our study was to evaluate a well-defined reasonable approach to catheter ablation of persistent atrial fibrillation. The strategy consisted of a circumferential pulmonary vein ablation in combination with a potential-guided segmental approach to achieve complete pulmonary vein isolation and a linear lesion at the roof of the left atrium.     

ATP对阵发性心房颤动环肺静脉电隔离术后疗效判断的价值

目的探讨三磷酸腺苷（ATP）对阵发性心房颤动患者环肺静脉电隔离（CPVI）术后左房-肺静脉电传导恢复的影响。方法75例阵发性心房颤动患者在完成消融术后两次给予三磷酸腺苷诱导肺静脉电传导恢复,对肺静脉电位恢复者补充消融重新到达肺静脉隔离。另有对照组84例阵发性心房颤动患者常规完成消融术后不做诱导试验。比较两组患者心房颤动术后复发率。结果试验组心房颤动复发率21.33％,对照组心房颤动复发率30.95％,差异有统计学意义（ P＜0.05）。结论补充消融三磷酸腺苷“暴露”的肺静脉电传导间隙,可减少阵发性心房颤动的复发率。     

Vorhofflimmerablation: Wer kommt in Frage?

Atrial fibrillation ablation is, since the introduction of the guidelines in 2006 and which were updated in 2007, now a standard procedure in many electrophysiological centers. Pulmonary vein isolation has proven itself as a way to eliminate focal triggers. From pathophysiological studies of atrial fibrillation development, it is known that ablation performed early in paroxysmal atrial fibrillation has the highest chance for success. In patients with persistent or permanent atrial fibrillation, success rates are lower and repeat interventions are needed more often. Therefore, continuation of antiarrhythmic drug therapy is often necessary in these patient groups. Thus, the curative use of ablation for atrial fibrillation is only possible with the current techniques for patients with paroxysmal atrial fibrillation.     

Persistent atrial fibrillation; It is time to regroup

Pulmonary vein isolation (PVI) is the only proven ablation strategy for paroxysmal and persistent atrial fibrillation (AF). However, when AF recurs despite durable PVI in a subgroup of patients with persistent AF, there is no scientifically proven ablation strategy to pursue. Here, we summarized how we approach persistent AF at Johns Hopkins Hospital.     

肺静脉电隔离术联合碎裂电位消融治疗持续性房颤疗效观察

目的：观察肺静脉电隔离术（ pulmonary vein isolation , PVI ）联合碎裂电位（ complex fractionated atrial electrograms , CFAE）消融对持续性房颤的疗效。方法对比观察23名于本院行房颤射频消融术的持续性房颤患者,所有患者均行PVI及左房顶部线性消融,其中12例联合CFAE消融,术后随访1年;观察两组手术时间、X线曝光时间、消融时间、手术并发症、左房大小、左房血栓、一次手术成功率等指标。结果联合CFAE消融组总手术时间（252±35） min、X线曝光时间（42±9．1）min、消融时间（94±11）min,单纯行PVI 组分别为（176±22）min、（34±7．6）min、（63±8）min,联合CFAE消融组手术各时间均明显延长（P＜0．01）;两组手术并发症、对左房大小及左房血栓的影响比较差异均无统计学意义;联合CFAE消融组一次手术成功率（75％）明显高于单纯行PVI组（64％）（ P＜0．05）。结论 PVI联合CFAE消融治疗持续性房颤虽增加手术、消融及X线曝光时间,但并不会提高并发症发生率,可提高房颤消融的一次手术成功率。     

Fibrillating areas isolated within the left atrium after radiofrequency linear catheter ablation

INTRODUCTION: Nonpulmonary vein sources have been implicated as potential drivers of atrial fibrillation (AF). This observational study describes regions of fibrillating atrial tissue isolated inadvertently from the left atrium (LA) following linear catheter ablation for AF. METHODS AND RESULTS: We report four patients with persistent/permanent AF who underwent pulmonary vein isolation with additional linear lesions and who presented with recurrent AF (mean AF cycle length [AFCL] 175-270 ms). Further catheter ablation resulted in the inadvertent electrical isolation of significant areas of the LA in which AF persisted at the same AFCL as was measured prior to disconnection, despite the restoration of sinus rhythm (SR) in all other left and right atrial areas, strongly suggesting that these islands were driving the remaining atria into fibrillation. The disconnected areas were located in the lateral LA, including the left atrial appendage (LAA) in three patients (limited to the LAA in one) and in the posterior LA in one patient. These isolated fibrillating regions represented 15-24% of the global LA surface, as estimated by electroanatomic mapping. CONCLUSION: Fibrillation can be maintained within electrically isolated regions of the LA following catheter ablation of AF, demonstrating the importance of atrial drivers in the maintenance of AF. Further mapping of these drivers is needed to characterize their mechanism and thereby allow for a more specific ablation strategy.