Initiation of atrial fibrillation by ectopic beats originating from the ostium of the inferior vena cava

Ectopic beats triggering atrial fibrillation may arise from atrial myocardial extensions in the pulmonary veins, superior vena cava, coronary sinus, and vein of Marshall. We report two patients with paroxysmal atrial fibrillation initiated by ectopic beats originating from the inferior vena cava. The foci responsible for the ectopic beats were located and ablated, resulting in elimination of atrial fibrillation. Ectopic beats originating from the os of the inferior vena cava can result in atrial fibrillation. This finding may explain the recurrence of atrial fibrillation in some patients after pulmonary vein isolation.     

药物治疗肺静脉和腔静脉电隔离术后阵发性心房颤动

目的 探讨阵发性心房颤动肺静脉和腔静脉电隔离术后早期复发患者药物治疗方法。方法 阵发性心房颤动患者32例，行肺静脉和腔静脉电隔离术后，均给予美托洛尔治疗，早期复发患者加用普罗帕酮，若仍不能控制心房颤动发作，则给予索他洛尔替代上述两药。结果 美托洛尔加普罗帕酮控制阵发性心房颤动的有效率54％。索他洛尔的有效率达83％。控制心房颤动总有效率92％，未发现严重不良反应。所用剂量小于常规剂量。结论 美托洛尔加小剂量的普罗帕酮，或单用小剂量索他洛尔可有效地控制阵发性心房颤动肺静脉和腔静脉电隔离术后早期复发患者的发作。     

Radiofrequency catheter ablation of atrial fibrillation initiated by spontaneous ectopic beats

Several reports have demonstrated that most paroxysmal atrial fibrillation is initiated by ectopic beats from a focal area, and radiofrequency catheter ablation can effectively cure atrial fibrillation. Although most of the ectopic beats originate from the orifices of the pulmonary veins or from the myocardial sleeves in the pulmonary veins, ectopic beats can also originate from superior vena cava, crista terminalis, coronary sinus, ligament of Marshall, or left atrial posterior free wall. Owing to the potential risk and complexity of catheter ablation, the ideal candidates should have frequent episodes and drug refractory paroxysmal atrial fibrillation.     

Inducibility of atrial arrhythmias after adenosine and isoproterenol infusion in patients referred for atrial fibrillation ablation

INTRODUCTION AND OBJECTIVES: The identification and ablation of atrial ectopic foci could complement the conventional empirical pulmonary vein approach and may increase the success rate of atrial fibrillation ablation. Although both adenosine and isoproterenol infusion have been reported to induce ectopics, no clear findings on their use during ablation have been published. Our aim was to investigate the utility of these two pharmacologic maneuvers in patients referred for atrial fibrillation ablation. METHODS: The effects of adenosine infusion, isoproterenol infusion, or both were evaluated in 53 patients with refractory atrial fibrillation referred for ablation. Patients were in sinus rhythm during evaluation. RESULTS: Administration of adenosine or isoproterenol induced atrial arrhythmias in 46 patients (87%). Arrhythmia inducibility was similar in those with paroxysmal and those with persistent atrial fibrillation (87% and 86%, respectively). Atrial ectopics alone were induced in 31 patients (65%), atrial tachycardia in four (8%), and atrial fibrillation in 13 (27%). In 10 patients (19%), ectopic foci were located outside the pulmonary veins and subsequently underwent ablation. In 32 of the 46 patients with inducible arrhythmias, only the induced ectopic foci were ablated (mean 1.4 [0.6] targets per patient). The long-term success rate of first procedures was 66%. CONCLUSION: Adenosine and isoproterenol infusion induced atrial ectopics in most patients with drug-refractory atrial fibrillation while they were in sinus rhythm. In almost 20%, the ectopic foci were located outside the pulmonary veins. The effectiveness of induced ectopic-guided ablation observed in our patient series supports the clinical utility of this approach.     

Catheter Ablation for Long-Standing Persistent Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and represents a major burden to health care systems. Atrial fibrillation is associated with a 4- to 5-fold increased risk of thromboembolic stroke. The pulmonary veins have been identified as major sources of atrial triggers for AF. This is particularly true in patients with paroxysmal AF but not always the case for those with long-standing persistent AF (LSPAF), in which other locations for ectopic beats have been well recognized. Structures with foci triggering AF include the coronary sinus, the left atrial appendage (LAA), the superior vena cava, the crista terminalis, and the ligament of Marshall. More than 30 studies reporting results on radiofrequency ablation of LSPAF have been published to date. Most of these are observational studies with very different methodologies using different strategies. As a result, there has been remarkable variation in short- and long-term success, which suggests that the optimal ablation technique for LSPAF is still to be elucidated. In this review we discuss the different approaches to LSPAF catheter ablation, starting with pulmonary vein isolation (PVI) through ablation lines in different left atrial locations, the role of complex fractionated atrial electrograms, focal impulses and rotor modulation, autonomic modulation (ganglionated plexi), alcohol ablation, and the future of epicardial mapping and ablation for this arrhythmia. A stepwise ablation approach requires several key ablation techniques, such as meticulous PVI, linear ablation at the roof and mitral isthmus, electrogram-targeted ablation with particular attention to triggers in the coronary sinus and LAA, and discretionary right atrial ablation (superior vena cava, intercaval, or cavotricuspid isthmus lines).     

环状标测电极指导下射频消融治疗阵发性房颤的临床分析

目的探讨环状标测电极指导下射频消融治疗阵发性心房颤动的疗效。方法对23例阵发性房颤患者在环状电极指示下行经验性肺静脉和（或）上腔静脉电隔离。结果23例阵发性房颤患者中共隔离肺加上腔静脉87条，左上肺静脉22条，左下肺静脉18条，右上肺静脉22条，右下肺静脉12条，上腔静脉13条，平均每例3．78条。平均操作时间和X线透视时间分别为（148±34）min和（52±9）min。1例发生术中心包填塞，2例行2次手术。平均随访（3．8±1．6）个月，20例无房颤复发，2例有房早发作，成功22例。结论阵发性心房颤动采用环状标测电极指导下射频消融电隔离术对绝大多数患者是有效的，并能改善患者的心功能情况。     

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。     

射频消融肺静脉电隔离术治疗阵发性房颤20例

目的观察电生理标测指导下肺静脉电隔离术治疗阵发性房颤的临床疗效.方法阵发性房颤患者20例,环状电极指示下对肺静脉行射频消融电隔离术.结果20例患者共接受心脏大静脉电隔离治疗28次(6例进行了第2次,1例进行了第3次),隔离静脉68根,肺静脉62根,上腔静脉6根,在房颤心律下消融58根,62根肺静脉中54根达到消触终点.平均操作时间和X线透视时间分别为(120±18)min和(32±9)min.平均随访(5.0±2.3)个月,示13例无房颤发作、2例房颤发作明显减少,总有效率达75%.结论肺静脉电隔离术治疗阵发性房颤具有较好临床疗效.     

Curative treatment of atrial fibrillation 2000: percutaneous catheter ablation techniques and intraoperative ablation with minimally invasive techniques

Summary Experimental and clinical mapping studies have indicated that the initiation of atrial fibrillation has to be differentiated from the perpetuation. Curative treatment of atrial fibrillation is one of the main challenges of today's electrophysiology, and the trigger as well as the substrate have recently been targeted. The arrhythmogenic foci which have been identified as being critical for the initiation of paroxysmal atrial fibrillation have been found in the vast majority of patients in the area of the proximal pulmonary veins. In a subset of patients with paroxysmal atrial fibrillation, these firing foci may be the only electrophysiologic abnormality. In other patients, different atrial arrhythmia types may be driven by pulmonary vein foci. Haissaguerre et al. have introduced mapping strategies to identify active foci within the pulmonary veins. The success rate of percutaneous pulmonary vein focus ablation strongly depends on the number of active foci. In contrast to elimination of the initiating triggers in patients with paroxysmal atrial fibrillation, modification of the maintaining substrate of atrial fibrillation is the alternative target for ablation in patients with chronic atrial fibrillation or in patients with prolonged episodes of paroxysmal atrial fibrillation. Different linear lesion line concepts within the right and/or left atrium have been followed within the last few years with moderate success rates. The lesion geometries that have been applied percutaneously so far seem to be empirical, and no successful lesion geometry concept for percutaneous application has been validated. A surgical curative treatment concept for patients with chronic atrial fibrillation is the maze procedure introduced by Cox et.al. which, however, is an extensive and time consuming surgical technique. Within the last few years, several attempts have been made to develop alternative surgical treatment strategies that should be safe, effective, and easy to apply. One of the promising new concepts is the intraoperative radiofrequency ablation of atrial fibrillation by elemination of anatomically determined so-called anchor reentrant circuits involving the pulmonary vein orifices and the mitral annulus. In this review, data on percutaneous ablation of pulmonary vein foci, percutaneous placement of linear right and/or left atrial lesion lines and, finally, intraoperative radiofrequency (RF) ablation using minimally invasive techniques are summarized.     

Pulmonary vein dimensions and variation of branching pattern in patients with paroxysmal atrial fibrillation using magnetic resonance angiography

Pulmonary veins are the most frequent origin of focal and paroxysmal atrial fibrillation. Although radiofrequency ablation has been attempted for the treatment of focal and paroxysmal atrial fibrillation, the anatomy of the pulmonary vein is still not fully understood. To investigate the dimensions and anatomical variation of the pulmonary vein in patients with paroxysmal atrial fibrillation, we performed breath-hold gadolinium enhanced magnetic resonance (MR) angiography using a 1.5 T cardiac MR imager (GE CV/i) in 32 patients with paroxysmal atrial fibrillation (61 +/- 8 years old), 11 patients with chronic atrial fibrillation (64 +/- 9 years old), and 26 patients with normal sinus rhythm (55 +/- 15 years old). Three dimensional images of the pulmonary veins were thus obtained, and the diameters of the most proximal portion of the left or right superior pulmonary vein and left or right inferior pulmonary vein were measured. Pulmonary vein branching variations were determined by a visual qualitative analysis by two separate readers' agreements, who were blinded to any clinical information. We focused on the existence of a complex-branching pattern draining into the orifice of four pulmonary veins. Patients with either paroxysmal atrial fibrillation or chronic atrial fibrillation showed larger superior pulmonary veins than those with normal sinus rhythm (mean +/- SD; in the left superior pulmonary vein, 20 +/- 3 mm, 23 +/- 3 mm vs 16 +/- 3 mm, P < 0.05; in right superior pulmonary vein, 19 +/- 4 mm, 19 +/- 2 mm vs 16 +/- 2 mm, P < 0.05). Complex-branching pattern was frequently observed in inferior pulmonary veins in patients with either paroxysmal atrial fibrillation or chronic atrial fibrillation; 25/32 patients with paroxysmal atrial fibrillation, 11/11 patients with chronic atrial fibrillation, compared to 7/26 patients with normal sinus rhythm. Complex-branching patterns were not observed in superior pulmonary veins in any patients in this cohort. CONCLUSION: In patients with paroxysmal atrial fibrillation or chronic atrial fibrillation, significant pulmonary vein dilation occurred mainly in the superior pulmonary veins, while a complex-branching pattern was frequently observed in the inferior pulmonary veins. These MR angiographic findings might be useful when performing radiofrequency ablation procedures and catheter manipulation for the treatment of paroxysmal atrial fibrillation.     

Electrogram-guided isolation of the left superior vena cava for treatment of atrial fibrillation.

AIMS: Radiofrequency ablation targeting the pulmonary veins offers potential cure for patients with symptomatic paroxysmal atrial fibrillation (AF). Initiating ectopics can also arise from other sites including the major thoracic veins, vein of Marshall and more rarely, persistent left superior vena cava (LSVC). We report our experience with arrhythmogenic persistent LSVC initiating AF. METHODS AND RESULTS: The LSVC was present in four patients from an overall series of 204 patients undergoing AF ablation at our centre. All were males, mean age 50 +/- 11 years. All patients underwent pre-procedure transesophageal echocardiography. The mapping of the LSVC was performed with a circumferential mapping catheter following pulmonary vein isolation. Atrial ectopics from the LSVC were observed to initiate AF. Catheter ablation (power controlled mode; 65 degrees C and 30 W at irrigation flow rate of 30 mL/min) resulted in electrical isolation of the LSVC in all patients and was accompanied by termination of AF in one of four patients. There were no complications. All patients underwent multiple procedures (three procedures in one patient, two procedures in three patients). After a mean follow-up of 18 +/- 7 months (range 7-24 months), three of the four patients remained free of AF off antiarrhythmic medications. CONCLUSION: Arrhythmogenic foci within persistent LSVC can result in AF despite electrical isolation of pulmonary veins. This report demonstrates the importance of the LSVC as a potential source of atrial ectopics initiating and perpetuating AF.     

Ablation of a single pulmonary vein arrhythmic focus triggering several supraventricular arrhythmias.

Pulmonary veins are a well-recognized source of focal ectopies that may trigger atrial fibrillation. Many ablative strategies, in particular ablation of the four pulmonary vein ostia, have been developed in order to cure atrial fibrillation. In some patients, the predominant arrhythmia may be an ectopic atrial tachycardia arising from a pulmonary vein and atrial fibrillation may be only a consequence of rapid atrial activation. There is a paucity of data regarding the electrocardiographic and electrophysiological characteristics of pulmonary vein tachycardia and the ablation strategy of this arrhythmia. In the present paper, we describe a case of a young woman with an arrhythmic focus localized in the right superior pulmonary vein with episodes of atrial tachycardia, paroxysmal atrial fibrillation and atrial flutter, who was successfully treated with transcatheter ablation.     

Identification of pulmonary vein foci by non-contact mapping in patients with paroxysmal atrial fibrillation.

AIMS: Ectopies from the pulmonary veins may cause paroxysmal atrial fibrillation and their discrete ablation may be curative. In the absence of focal activity during the procedure, identification of target sites with conventional techniques is difficult. We investigated the feasibility of non-contact mapping (EnSite) for identification and successful ablation of pulmonary vein foci in such cases. METHODS AND RESULTS: We studied 7 patients with idiopathic paroxysmal atrial fibrillation referred for percutaneous ablation and not presenting spontaneous or inducible atrial premature beats during the procedure. An EnSite balloon catheter and an ablation catheter (NaviStar) were placed inside the left atrium. The ablation catheter was also used for electroanatomic mapping (CARTO) of specific sites. Multiphasic pulmonary vein potentials were detected on virtual electrograms and tagged on the non-contact map and confirmed with conventional mapping. The procedural endpoint was elimination or dissociation of the multiphasic potential. Non-contact mapping identified 13 foci of multiphasic potentials in the seven patients (5 foci were initially identified by EnSite), and discrete ablation suppressed 9 of them (69%). Six months later, 4 of the 5 patients in whom all foci were suppressed remain asymptomatic, in sinus rhythm, under no medication. CONCLUSION: In patients with paroxysmal atrial fibrillation and no ectopic activity during electrophysiological study virtual electrograms may complement conventional techniques in detecting hidden pulmonary vein foci and may be used to evaluate ablation efficacy.     

经导管射频消融治疗局灶性心房颤动

报道19例局灶性心房颤动（简称房颤）射频消融治疗的结果,其中药物治疗无效且发作频繁（＞1次／日）的阵发性房颤17例、慢性房颤2例。17例患者尚同时合并有频发房性早搏（简称房早）（动态心电图显示＞700个／日）。同步记录高位有房、冠状静脉窦及左、右上肺静脉电图。根据房早或房颤开始发作时的心房激动顺序确定异位兴奋灶部位,以局部双极电图较体表心电图P'波起点最提前处为消融靶点。成功标准为消融后6Omin内房早／房颤消失及随访期内可以无须药物而维持窦性心律。结果：92．6％（25／27）的异位兴奋灶位于肺静脉,其中尤以双上肺静脉居多（21／25）。随访2．4±3．7个月后有13例患者（68．4％）达上述成功标准,其房早数目由术前的3720±2741个／日降至216±139个／日,除1例发生心房穿孔外无其他严重并发症。结论：射频消融治疗局灶性房颤效果较好,可以作为药物治疗无效的阵发性房颤患者的治疗选择。     

心房颤动上腔静脉节段性电隔离方法及安全性评估

目的:分析心房颤动(房颤)上腔静脉节段性电隔离的具体手术方法,并评估其安全性.方法:入选2017年11月至2018年9月期间我院阵发性房颤患者50例,患者常规进行肺静脉隔离后,继续行上腔静脉隔离.消融前进行上腔静脉造影,显示上腔静脉与右心房解剖关系,并在CARTO系统运用PentaRay电极导管进行上腔静脉及右心房三维...     

Atrial Fibrillation: Role of Arrhythmogenic Foci

Atrial fibrillation, the most common of all sustained cardiac arrhythmias can be cured by Surgical atriotomies or linear RF catheter ablation. We have investigated the role of focal RF ablation in paroxysmal atrial fibrillationMethods: sixteen patients with focal atrial fibrillation (extrasystoles, atrial tachycardia and atrial fibrillation due to the same focus firing irregularly at different rates) and 45 with common AF initiated by extrasystolic foci were included. The ablation site was determined on the basis of earliest bipolar activity relative to a stable atrial electrogram reference or to the P wave onset during atrial fibrillation initiation.Results: All the patients with focal atrial fibrillation were treated with a mean of 5 ± 4 RF applications delivered on a right atrial site (n = 4) or on a pulmonary venous site (n = 13), (one patient had 2 foci). Sixty nine foci (located in the pulmonary veins in 94%) were identified in the 45 patients with common atrial fibrillation initiated by extrasystoles. They were ablated with a mean of 4.5 ± 2 RF applications. Using a mean follow up of 8 ± 6 months, 28/45 (62%) were cured without antiarrhythmic drugs.Conclusion: Pulmonary veins play an important role in paroxysmal atrial fibrillation. They are the most frequent source of focal atrial fibrillation and of initiating foci amenable to RF ablation.     

Ablation of atrial fibrillation: where are we now?]

Atrial fibrillation is the commonest arrhythmia. Besides the risk of complications, a significant number of patients remain symptomatic despite the different anti-arrhythmic drugs currently available. The only curative treatment is by surgery or catheter ablation. Since 1994, several approaches have been developed based on two main concepts: modification of the arrhythmogenic substrate by linear lesion to prevent the perpetuation of the arrhythmia and ablation of the foci initiating the atrial fibrillation. The later approach is the most popular one at the moment because the concentration of foci at the site of the pulmonary veins makes it possible to isolate them relatively easily. The presence of atrial foci in some patients complicates matters and limits the success rate to 70%. Despite these limitations and with an acceptable rate of complications, this approach appears preferable to His bundle ablation in young patients with symptomatic paroxysmal atrial fibrillation resistant to antiarrhythmic therapy.     

阵发性心房颤动患者非肺静脉触发灶的诱发及消融

目的探讨环肺静脉电隔离（CPVI）术中静脉注射异丙肾上腺素（ISO）和三磷酸腺苷：ATP）,在检出阵发性心房颤动（房颤）非肺静脉触发灶中的价值。方法回顾性分析2010年4～12月色浙江邵逸夫医院心内科所有患者接受三维标测系统指导下CPVI术136例患者,其中87例消融前后分别应用ISO＋ATP诱发房颤,Lasso导管置于右上肺静脉口、消融导管置于左上肺静脉中,结合冠状静冰窦导管判断房颤的触发灶,然后通过消融验证。结果87例首次接受导管消融的阵发性房颤患者,吏用ISO＋ATP后16例证实有非肺静脉房颤触发灶。其中,消融前诱发8例房颤、1例房性心动过速（房塞）、1例频发房性早搏（房早）。2例消融前诱发的患者CPVI术后房性快速性心律失常（ATa）仍存在,余8例及5例消融前未被诱发者CPVI后再次诱发时又检出非肺静脉触发灶。其中,9例为房颤（起源上腔静脉5例、冠状静脉窦内靠近口部1例、左心房后壁2例、不明1例）,3例房性心动过速（均为冠状挣脉窦口起源）和1例频发房性早搏（上腔静脉起源）。14例患者在相应非肺静脉触发灶部位消融后心聿失常均终止,且不再被诱发。2例起源不明的房颤患者电复律后转为窦性心律。随访2年,单次手术或功率为87．5％（14／16）。结论静脉注射ISO＋ATP可简单有效地检出阵发性房颤非肺静脉触发灶。     

Impact of Systematic Isolation of Superior Vena Cava in Addition to Pulmonary Vein Antrum Isolation on the Outcome of Paroxysmal, Persistent, and Permanent Atrial Fibrillation Ablation: Results from a Randomized Study

Impact of the Systematic Isolation of the Superior Vena Cava.   Background: Pulmonary veins (PVs) have been shown to represent the most frequent sites of ectopic beats initiating paroxysmal atrial fibrillation (AF). However, additional non-PV triggers, arising from different areas, have been reported as well. One of the most common non-PV sites described is the superior vena cava.
Aims: The purpose of the study was to investigate the impact resulting from the systematic isolation of the superior vena cava (SVCI) in addition to pulmonary vein antrum isolation (PVAI) on the outcome of paroxysmal, persistent, and permanent AF ablation.
Methods: A total of 320 consecutive patients who had been referred to our center in order to undergo a first attempt of AF ablation were randomized into 2 groups. Group I (160 patients) underwent PVAI only; Group II (160 patients) underwent PVAI and SVCI.
Results: AF was paroxysmal in 134 (46%), persistent in 75 (23%), and permanent in 111 (31%) of said patients. SVCI was performed on 134 of the 160 patients (84%) in Group II. SVC isolation was not performed on the remaining 26 patients either because of phrenic nerve capture or the lack of SVC potentials. Comparison of the outcome data between the 2 groups, after a follow-up of 12 months, revealed a significant difference in total procedural success solely with patients manifesting paroxysmal atrial fibrillation (56/73 [77%] Group I vs. 55/61 [90%] Group II; P = 0.04; OR 2.78).
Conclusions: In our study, the strategy of the empiric SVCI in addition to PVAI has improved the outcome of AF ablation solely in patients manifesting paroxysmal AF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1–5, January 2010)     

Effect of atrial overdrive pacing on pulmonary vein focal discharge in patients with atrial fibrillation.

AIMS: Recently, it has been shown that atrial fibrillation may be caused by spontaneously discharging foci located predominantly in the pulmonary veins. However, the effect of atrial overdrive pacing on these pulmonary vein foci has not been studied. METHODS AND RESULTS: In 58 patients with drug refractory paroxysmal or persistent atrial fibrillation we performed radiofrequency catheter ablation of arrhythmogenic triggers inside the pulmonary veins and/or an ostial pulmonary vein isolation with conventional mapping and ablation technology. Continuous bigeminal pattern of discharge from one or more arrhythmogenic pulmonary veins was recorded in 14 patients. Atrial overdrive pacing resulted in suppression of pulmonary vein 'focus' activity in all patients. The longest mean atrial pacing cycle length resulting in overdrive suppression was 587+/-114 ms. Independent of pacing rate and duration, bigeminal pulmonary vein focus activity reemerged 2.5+/-3.7s after cessation of pacing. Overdrive suppression of the pulmonary vein focus was incomplete in 9 pacing attempts, and resulted in induction of atrial fibrillation from the same vein in 3 of 31 pacing manoeuvres. At 2 years follow-up 79% of these patients were free of atrial fibrillation, 55% without antiarrhythmic drugs, 24% on previously ineffective antiarrhythmic drug therapy. CONCLUSION: Stable pulmonary vein 'focus' activity in patients with atrial fibrillation can be suppressed by atrial overdrive pacing. However, 'proarrhythmic' effects of atrial overdrive pacing, such as induction of atrial fibrillation, were also seen.