A multi-purpose spiral high-density mapping catheter: initial clinical experience in complex atrial arrhythmias

Purpose

There is an increasing need for catheter ablation procedures to treat complex atrial tachycardias (AT) and atrial fibrillation (AF), often requiring detailed endocardial mapping. The sequential point-to-point contact mapping of complex arrhythmias is time-consuming and may not always be feasible. We assessed the utility of a novel spiral duo-decapolar high-density (HD) mapping catheter to delineate complex arrhythmia substrates for ablation.

Methods

The patients underwent HD mapping using a spiral catheter (AFocusII) and the EnSite NavX system, during catheter ablation procedures, to treat atrial arrhythmias.

Results

In 26 patients, a total of 32 atrial arrhythmias were mapped and ablated, comprising of five focal AT, eight macroreentrant AT, 11 persistent AF and eight paroxysmal AF. The HD catheter was used to acquire endocardial surface geometries in all cases and to map the pulmonary veins in patients undergoing AF ablation. In persistent AF, HD catheter mapping permitted the creation of highly detailed complex fractionated electrogram maps (left atrium 449?±?128 points in 7.2?±?2.6 min; right atrium 411?±?113 points in 6.7?±?1.6 min). In AT, activation mapping was performed with the acquisition of 305?±?158 timing points in 7.3?±?2.6 min, guiding successful ablation in all cases. During the follow-up of 7.0?±?2.6 months, all AT patients remained free of significant arrhythmia.

Conclusions

High-density contact mapping with a novel spiral multipolar catheter allows rapid assessment of focal and macroreentrant AT, and complex fractionated electrical activity in the atria. It has further multi-functional capabilities as a pulmonary vein mapping catheter and for accurate geometry creation when used with a 3D mapping system.     

Advanced mapping techniques in atrial fibrillation

Catheter ablation has emerged as an excellent treatment option for atrial fibrillation especially in patients with paroxysmal AF. Several obstacles however remain regarding ablation strategies for persistent and chronic AF. In this setting, adequate success rates can only be achieved with left atrial ablation in addition to complete PV isolation. Important techniques in this regard are mapping of complex fractionated atrial electrograms as well as identification of atrial sites serving as sources of persistent AF. Other mapping techniques reviewed in this article are rapid geometry acquisition with spiral catheters and the Ensite/NAVX system, the 64-pole Constellation basket catheter as well as the MESH Mapper catheter.     

Efficacy of extended antrum ablation based on substrate mapping plus pulmonary vein isolation in the treatment of atrial fibrillation

Introduction and objectivesPulmonary vein isolation (PVI) technique has become the cornerstone of atrial fibrillation (AF) catheter ablation. The objective of this study was to assess the efficacy and safety of extended antrum ablation based on electrophysiological substrate mapping plus PVI in AF patients who underwent cryoballoon ablation.MethodsIn this observational study, a total of 121 paroxysmal AF patients and 80 persistent AF patients who did not achieve the procedure endpoint after cryoballoon ablation received extra extended antrum ablation (EAA) based on electrophysiological substrate mapping via radiofrequency ablation (EAA group). As a control group (PVI group), among paroxysmal AF and persistent AF patients, we conducted a propensity score-matched cohort, in whom only PVI was completed.ResultsThe average follow-up time was 15.27±7.34 months. Compared with PVI group, paroxysmal AF patients in the EAA group had a significantly higher rate of AF-free survival (90.1% vs. 80.2%, p=0.027) and AF, atrial flutter, or atrial tachycardia (AFLAT) -free rate survival (89.3% vs. 79.3%, p=0.031). Persistent AF patients in the EAA group also had a significantly higher rate of AF-free survival (90.0% vs. 75.0%, p=0.016) and AFLAT-free survival (88.8% vs. 75.0%, p=0.029) than PVI group. Complication rates did not significantly differ between both groups, in either paroxysmal AF or persistent AF patients.ConclusionOur findings demonstrate that extra extended antrum ablation based on electrophysiological substrate mapping is effective and safe. Moreover, the strategy can improve the outcome of AF cryoablation.     

三维标测系统指导下环肺静脉消融治疗心房颤动

目的 探讨三维标测系统指导下环肺静脉消融治疗心房颤动的安全性和有效性.方法 阵发性心房颤动92例和持续性或永久性心房颤动36例,接受环肺静脉消融术.采用Carto电解剖标测系统,进行环肺静脉左心房线性消融,消融终点为肺静脉电隔离.手术结束时对心律仍为心房颤动者行同步直流电心脏复律.结果 完成"解剖学"环形消融线256条,其中58.6%达到电隔离肺静脉的终点,经寻找缝隙补充消融后最终248条(96.9%)消融线达到终点.手术时间(231±45)min、X线曝光时间(42±13)min和放电时间(66±17)min.术后随访平均10个月,无复发101例(78.9%).接受了再次手术15例,心内电生理检查证实14例有左心房-肺静脉传导,射频消融成功并随访30～270 d,两次射频消融术后总成功率为87.5%,其中阵发性心房颤动成功率为93.0%,持续性或永久性心房颤动为76.7%.并发症发生率为6.2%,包括心包填塞2例、小脑梗死2例、股静脉穿刺部位血肿1例和左侧大量血胸1例,经治疗后均痊愈.结论 以肺静脉电隔离为目标的环肺静脉消融术治疗心房颤动有效和安全.     

三维标测系统指导心房颤动导管消融的临床研究

目的 探讨三维标测系统指导下导管射频消融治疗心房颤动的有效性与安全性.方法 回顾性分析39例在三维标测系统指导下行环肺静脉线性消融术的心房颤动患者(其中阵发性心房颤动33例和持续性心房颤动6例)的临床资料,着重分析术前准备、标测及消融方法 、手术结果 、术后治疗和随访.结果 消融终点为Lagso标测的所有肺静脉均达到完全电学隔离,若消融结束后心房颤动仍未终止,即行同步直流电复律恢复窦性心律.39例患者共完成78条环形消融线,肺静脉完全电学隔离率为93.6%(73/78).手术操作时间为(245±56)min、X线曝光时间为(46±15)min.术后随访6个月～12个月,33例临床症状得到改善,无心房颤动复发,6例需服用抗心律失常药维持窦性心律,其中3例心房颤动复发患者接受再次导管消融后无发作.射频消融术后总成功率为84.6%(33/39).结论 三维标测系统指导下导管射频消融治疗心房颤动是安全和有效的治疗方法.     

国产ColumbusTM三维标测系统在心房颤动射频消融中的初步应用

目的报道国产ColumbusTM三维电解剖标测系统在射频消融治疗持续性心房颤动（简称房颤）中的初步应用经验。方法2012年3月至2013年4月入选持续性房颤患者10例作为实验组,术中两次穿刺房间隔成功后送入环形标测电极和冷盐水灌注消融电极导管,使用Columbus系统构建左房和肺静脉电解剖结构后行房颤消融。另取10例使用CaaoXP系统辅助消融的持续性房颤患者作为对照组。结果实验组和对照组患者术中均成功完成肺静脉电隔离和必的线性消融。与对照组相比,实验组建模时间、X线曝光时间和放电时间无显著性差异[分别为（11±4）minVS（9±4）min;（13±3）minVS（4±5）min;（35±8）minVS（33±9）min,P均〉0．05]。实验组总手术时间长于对照组[（135±20）minvs（120±17）min,P〈O．05]。两组在术中、术后均没有严重并发症出现。在术后至少1年的随访时间中,实验组和对照组分别有4例和5例患者复发。结论国产Columbus三维标测可安全有效地指导房颤的射频消融手术。     

三维电解剖标测指导下经导管射频消融治疗心房颤动的初步体会

目的探讨在三维电解剖标测系统(CARTO)指导下经导管射频消融治疗心房颤动(房颤)的安全性和有效性。方法将接受治疗的30例患者(阵发性房颤28例,持续性房颤2例)利用CARTO进行左心房重建后,对阵发性房颤患者行环绕同侧肺静脉的线性消融,射频消融终点为房颤终止且不能诱发;对持续性房颤患者进行左心房和冠状静脉窦的重建,标测射频消融复杂心房碎裂电位区,至房颤终止或行直流电转复。并检测其中16例阵发性房颤患者术后心脏生化标记物动态变化。结果28例阵发性房颤均达到射频消融终点,2例持续性房颤患者中,1例在射频消融中转为窦性心律,1例行直流电转复。术后随访2~14(5.6±3.5)个月,25例患者无房颤复发,单次手术成功率83.3%。16例患者术后第1天肌钙蛋白T由术前的(0.01±0.00)μg/L升至(2.20±0.99)μg/L(P<0.01)。结论在CARTO指导下射频消融治疗房颤安全有效,但肌钙蛋白T明显增高。     

Bi-atrial mapping of atrial arrhythmias

Cardiac mapping of atrial activation was originally performed in animals during open chest preparations, using epicardial electrodes. The development of endocardial egg-shaped multiple electrodes provided detailed assessment of the minimum number of wavelengths required to sustain atrial fibrillation (AF), as well as the role of interatrial connections during AF. Subsequently, several studies on bi-atrial epicardial high-density mapping in animals and humans also reported on the importance of interatrial connections, as well as the specific characteristics of the left atrium as compared with the right atrium during chronic AF. Endocardial bi-atrial mapping studies using electrode catheters were reported using basket-shaped catheters carrying 64 electrodes. Animal studies suggested that septal activation was asynchronous and discordant, while a human study outlined the multiple origins of atrial ectopic beats following DC cardioversion in patients with chronic atrial fibrillation. The advent of non-fluoroscopic mapping systems significantly changed our approach to percutaneous endocardial mapping. Simultaneous bi-atrial studies using electroanatomic mapping were performed in sinus rhythm as well as in atrial flutter. These studies demonstrated the predominance of interatrial conduction over Bachmann's Bundle and the coronary sinus-left atrial connection during respectively, sinus rhythm and atrial flutter. Simultaneous bi-atrial non-contact mapping was initially performed during porcine studies and later in humans, demonstrating asynchronous and discordant septal activation both during sinus rhythm or left lateral atrial pacing. Preliminary studies from simultaneous bi-atrial non-contact mapping in humans in whom AF occurred spontaneously or was induced suggests three main types of atrial activation, consisting of left atrial drivers causing the right atrium to fibrillate following conduction over interatrial connections, the right atrium independently sustaining AF, even after pulmonary vein disconnection, and both atria fibrillating independently without activation over interatrial connections. Bi-atrial mapping has been essential for our understanding of normal and abnormal atrial activation, and ultimately may provide new approaches for ablation of atrial fibrillation.     

Image integration in electroanatomic mapping

Abstract Over the past five years, integration of the pre-procedural MR/CT images with a 3D electroanatomic mapping system has been developed to facilitate catheter ablation of clinical arrhythmias. It presents a significant advantage over the less-detailed surrogate geometry created by the 3D mapping systems. The process of image integration consists of pre-procedural imaging, image segmentation and image registration. Clinical studies have demonstrated the feasibility and accuracy of the use of image integration to guide catheter ablation of atrial fibrillation (AF). Accurate registration of the 3D left atrial MR/CT image to the real-time catheter mapping space can be technically challenging. Several important considerations should be taken into account to minimize registration error. Enhanced ability of catheter navigation with image integration may improve the efficacy and safety of anatomically based ablation strategies such as ablations of AF and nonidiopathic ventricular tachycardia. New developments in the field include integration of pathophysiologic as well as real-time anatomic information to the 3D mapping systems, and the use of new navigation system to improve registration. Drs Dong and Dickfeld are consultants of and received research grants from Biosense Webster Inc.     

导管射频消融治疗持续性心房颤动的体会

目的研究持续性心房颤动(房颤)导管射频消融最佳手术方式及复发心律失常的处理策略。方法2005年3月~2007年8月共40例持续性房颤患者接受导管射频消融治疗,三维电解剖标测系统指导下行环同侧肺静脉左心房线性消融;2005年的12例患者部分附加左心房峡部、右心房峡部、左心房顶部线性消融;2006年的12例患者常规进行左心房峡部、右心房峡部射频消融,部分患者附加碎裂电位、左心耳或根据术中的房性心律失常附加其他部位射频消融;2007年的16例患者则在上述基础上进行冠状窦左心房心内膜面射频消融。结果2005年复发8例(66.7%),2006年复发3例(25.0%),2007年复发4例(25.0%)。复发的患者中8例接受第二次导管射频消融术,其中5例维持窦性心律。平均随访(17.6±10.4)个月,总治疗成功率82.5%。结论持续性房颤患者在以肺静脉口为核心的导管射频消融前提下,适当改进导管射频消融策略,可以显著提高成功率。     

Cryoballoon in atrial fibrillation ablation

Encouraging results of ablation therapy in patients with paroxysmal atrial fibrillation (AF) have prompted changes in professional practice guidelines. The most recent European guidelines have suggested that ablation might be offered as first-line therapy in selected patients. Cryoballoon ablation is a promising technology in interventional AF therapy. Two different sizes of the cryoballoon are currently available: a smaller (23?mm) and a larger (28?mm) balloon relative to the ostial diameter of the pulmonary veins. New tools, the circular mapping catheter and the use of intracardiac echocardiography, provide important periprocedural information. A meta-analysis of previous studies revealed outcome data with an AF-free survival rate of 72.83% at the 1-year follow-up in paroxysmal AF patients undergoing cryoballoon ablation. The most frequent, but reversible complication is phrenic nerve palsy with reported incidences up to 10%. All efforts must be taken to overcome this limitation, since the overall major complication rate tends to be lower in cryoballoon compared to radiofrequency ablation. In persistent AF, reported results in cryoballoon ablation had a limited success rate below 50% after a single procedure. A double balloon approach using both cryoballoon sizes might overcome some of the limitations in persistent AF. Prospective data and randomized studies are required. This article outlines the current status of cryoballoon technology in AF ablation therapy.     

Left atrial ablation versus biatrial ablation for persistent and permanent atrial fibrillation: a prospective and randomized study.

OBJECTIVES: The aim of this study was to compare--in patients with persistent and permanent atrial fibrillation (AF)--the efficacy and safety of left atrial ablation with that of a biatrial approach. BACKGROUND: Left atrium-based catheter ablation of AF, although very effective in the paroxysmal form of the arrhythmia, has an insufficient efficacy in patients with persistent and permanent AF. METHODS: Eighty highly symptomatic patients (age, 58.6 +/- 8.9 years) with persistent (n = 43) and permanent AF (n = 37), refractory to antiarrhythmic drugs, were randomized to two different ablation approaches guided by electroanatomical mapping. A procedure including circumferential pulmonary vein, mitral isthmus, and cavotricuspid isthmus ablation was performed in 41 cases (left atrial ablation group). In the remaining 39 patients (biatrial ablation group), the aforementioned approach was integrated by the following lesions in the right atrium: intercaval posterior line, intercaval septal line, and electrical disconnection of the superior vena cava. RESULTS: During follow-up (mean duration 14 +/- 5 months), AF recurred in 39% of patients in the left atrial ablation group and in 15% of patients in the biatrial ablation group (p = 0.022). Multivariable Cox regression analysis showed that ablation technique was an independent predictor of AF recurrence during follow-up. CONCLUSIONS: In patients with persistent and permanent AF, circumferential pulmonary vein ablation, combined with linear lesions in the right atrium, is feasible, safe, and has a significantly higher success rate than left atrial and cavotricuspid ablation alone.     

Automatic 3D mapping of complex fractionated atrial electrograms (CFAE) in patients with paroxysmal and persistent atrial fibrillation

Background: Complex fractionated atrial electrograms (CFAE) are a possible target for atrial fibrillation (AF) ablation and can be visualized in three‐dimensional (3D) mapping systems with specialized software. Objective: To use the new CFAE software of CartoXP® (Biosense Webster, Diamond Bar, CA, USA) for analysis of spatial distribution of CFAE in paroxysmal and persistent AF. Methods: We included 16 consecutive patients (6 females; mean 59.3 years) with AF (6 paroxysmal and 10 persistent) undergoing AF ablation. Carto maps of left atrium (LA) were reconstructed. Using the new CFAE software, the degree of local electrogram fractionation was displayed color‐coded on the map surface. LA was divided into four regions: anterior wall, inferior wall, septum, and pulmonary veins (PV). The relationship among regions with CFAE visualized and CFAE ablation regions (persistent AF only) was analyzed retrospectively. Results: In paroxysmal and persistent AF, CFAE were observed in all four LA regions. In paroxysmal AF, the density of CFAE around the PV was significantly higher than in other regions (P < 0.05) and higher than in persistent AF (P < 0.05). In persistent AF, CFAE were evenly distributed all over the LA. Of 40 effective ablation sites with significant AF cycle length prolongation, 33 (82.5%) were judged retrospectively by CFAE map as CFAE sites. Conclusion: CFAE software can visualize the spatial distribution of CFAE in AF. CFAE in persistent AF were observed in more regions of LA compared to paroxysmal AF in which CFAE concentrated on the PV. Automatically detected CFAE match well with ablation sites targeted by operators.     

Catheter ablation of atrial fibrillation guided by a 3D electroanatomical mapping system: a 2-year follow-up study from the Italian Registry On NavX Atrial Fibrillation ablation procedures (IRON-AF)

Aims

Clinical trials have established that atrial fibrillation (AF) catheter ablation improves symptoms in appropriately selected patients. Confirmation of these results by long-term prospective observational studies is needed. This registry was created to describe the experience of 16 Italian centers with a large cohort of AF patients treated with catheter ablation guided by the NavX 3D mapping system.

Methods

From November 2006 to May 2008, 545 consecutive patients (age 60.4?±?9.8, 67 % male) with paroxysmal (44 %), persistent (43 %), and long-standing persistent (13 %) AF referred for catheter ablation guided by the NavX system, were included in this registry. For this paper, follow-up was censored at 24 months; however, patients are being followed in the ongoing registry.

Results

Before the ablation, 80 % of patients failed to respond to at least one antiarrhythmic drug aimed at rhythm control. Pulmonary vein (PV) isolation guided by a circular mapping catheter was performed in 70 % of patients whereas non potential-guided PV encircling was performed in 30 % of patients. In 67 % of patients, additional left atrial (LA) substrate modification was performed. Image integration was performed in 9.2 % of patients. Considering a 3-month blanking period, after a single-ablation procedure, the patients had 1- and 2-year freedom from AF recurrence of 67.4 and 57.0 % (36.1 % off antiarrhythmic drugs), respectively. Cox regression analysis showed that AF recurrences during blanking (HR 2.1), and previous AF ablation (HR 3.3) were independent predictors of AF recurrences. Major procedure-related complications occurred in 53 patients (9.7 %). In 35 patients (6.7 %), a repeat procedure was performed at a median of 5 months after the initial procedure.

Conclusions

This prospective, multicenter clinical experience provides significant insights into current ablation care of patients with AF. Despite favorable outcomes, real-world complication rates appear higher than previously recognized.     

Sites of focal atrial activity characterized by endocardial mapping during atrial fibrillation.

OBJECTIVES: The aim of the present study was to assess the feasibility of identifying sites of focal atrial activity by localized high-density endocardial mapping during atrial fibrillation (AF). BACKGROUND: Sites of focal activity in the left atrium have been demonstrated by epicardial mapping during AF. METHODS: Twenty-four patients (15 with paroxysmal, 3 with persistent, and 6 with permanent AF) underwent endocardial mapping during AF. A 20-pole catheter with five radiating spines was used to map both atria for 30 s in each of 10 pre-determined segments. A focal activity was defined as > or =3 atrial cycles with activation spreading from center to periphery of the mapping catheter. Catheter ablation was performed independent of the mapping results. RESULTS: Spontaneous focal activities were observed in 13 sites in the left atrium (9%; anterior 1, roof 2, posterior 6, inferior 4) in 12 patients (9 paroxysmal, 3 persistent). Focal activity was observed continuously (two sites) or intermittently (11 sites, median 5 episodes), and associated with shortening of the cycle length (from 183 +/- 33 ms to 172 +/- 29 ms; p < 0.05). The mean duration of an intermittent episode was 1.5 s (range 0.4 to 7.1 s). Atrial fibrillation terminated without ablation at the foci in all of 12 patients, but in 2 of them, re-initiated arrhythmia was successfully ablated at these foci. Nine of these 12 patients (75%) were arrhythmia-free without antiarrhythmic drugs during a follow-up period of 7.0 +/- 3.1 months. CONCLUSIONS: Termination of AF without ablation at the sites of atrial focal activity suggests that this activity may be triggered by impulses originating from other regions, such as the pulmonary veins.     

三维电解剖标测及单根环状标测电极指导下CPVA术治疗心房颤动

目的探讨在三维电解剖标测及单根环状标测电极指导下以环肺静脉口电隔离术（CPVA）为核心治疗心房颤动（房颤）的疗效。方法对32例房颤患者均在CARTO三维电解剖标测及单根环状标测电极指导下行CPVA,其中辅助行碎裂电位消融6例,上腔静脉消融术2例,三尖瓣峡部、二尖瓣峡部及冠状窦内消融各1例。结果26例阵发性房颤不再被诱发,6例慢性房颤中术中房颤终止2例、电复律转为窦性心律4例;手术操作时间（119&#177;37）min,X线透视时间（25&#177;12）min;随访（9&#177;5）个月成功率为90.6%。均无手术并发症。结论三维电解剖标测及单根环状标测电极指导下以CPVA为核心,其他消融方法为辅的房颤消融策略安全有效,可提高消融成功率,缩短手术时间,减少并发症、复发。     

Validation of computed tomography image integration into the EnSite NavX mapping system to perform catheter ablation of atrial fibrillation

Introduction: The complex anatomy of the left atrium (LA) makes location of ablation catheters difficult using fluoroscopy alone, and therefore 3D mapping systems are now routinely used. We describe the integration of a CT image into the EnSite NavX System with Fusion and its validation in patients undergoing atrial fibrillation (AF) or left atrial tachycardia (AT) catheter ablation. Methods and Results: Twenty‐three patients (61 ± 9.2 years, 16 male) with paroxysmal (14) and persistent (8) AF and persistent (1) AT underwent ablation using CT image integration into the EnSite NavX mapping system with the EnSite Fusion Dynamic Registration software module. In all cases, segmentation of the CT data was accomplished using the EnSite Verismo segmentation tool, although repeat segmentation attempts were required in seven cases. The CT was registered with the NavX‐created geometry using an average of 24 user‐defined fiducial pairs (range 9 to 48). The average distance from NavX‐measured lesion positions to the CT surface was 3.2 ± 0.9 mm (median 2.4 mm). A large, automated, retrospective test using registrations with random subsets of each patient's fiducial pairs showed this average distance decreasing as the number of fiducial pairs increased, although the improvement ceased to be significant beyond 15 pairs. In confirmation, those studies which had used 16 or more pairs had a smaller average lesion‐to‐surface distance (2.9 ± 0.7 mm) than those using 15 or fewer (4.3 ± 0.8 mm, P < 0.02). Finally, for the 13 patients who underwent left atrial circumferential ablation (LACA), there was no significant difference between the circumference computed using NavX‐measured positions and CT surface positions for either the left pulmonary veins (178 ± 64 vs. 177 ± 60 mm; P = 0.81) or the right pulmonary veins (218 ± 86 vs. 207 ± 81 mm; P = 0.08). Conclusion: CT image integration into the EnSite NavX Fusion system was successful in all patients undergoing catheter ablation. A learning curve exists for the Verismo segmentation tool; but once the 3D model was created, the registration process was easily accomplished, with a registration error that is comparable with registration errors using other mapping systems with CT image integration. All patients went on to have subsequent successful ablation procedures. Where LACA was performed (13 patients), only four patients required segmental ostial lesions to achieve electrical isolation.     

经导管射频消融治疗起源于肺静脉的心房颤动(附二例报告)

报道 2例经射频消融治疗成功的起源点位于肺静脉的心房颤动 (简称房颤 ) ,均伴有频发房性早搏 (简称房早 )的阵发性房颤。电生理检查时行两次房间隔穿刺 ,将两根 10极标测导管通过长鞘送入左、右上肺静脉 ,选择性肺静脉造影证实肺静脉开口部位。静脉滴注异丙肾上腺素后 1例诱发出频发房早 ,另 1例诱发出频发房早及房颤 ,且房早及房颤开始发作时的心内电图均显示最早心房激动点位于右上肺静脉内 ,其局部电位分别较体表心电图异位 P波的起点提前 61和 96ms。在最早心房激动点处以 15～ 2 0 W的输出功率消融 60～ 180 s后房早及房颤消失 ,静脉滴注异丙肾上腺素亦未再诱发房颤。术后随访 8～ 12个月 ,房颤无复发。结论 :射频消融治疗起源于肺静脉的房颤效果较好且相对安全 ;在这类患者应用两根多极导管同步标测双上肺静脉是一种有效的标测和消融方法。     

Validation of three-dimensional cardiac image integration: use of integrated CT image into electroanatomic mapping system to perform catheter ablation of atrial fibrillation

INTRODUCTION: Accurate visualization of the complex left atrial (LA) anatomy and the location of an ablation catheter within the chamber is important in the success and safety of ablation for atrial fibrillation (AF). We describe the integration of CT into an electroanatomic mapping (EAM) system and its validation in patients undergoing catheter ablation for AF. METHODS AND RESULTS: Thirty patients (59.2 +/- 8 years, 25 M) with paroxysmal (12) and persistent (18) AF underwent ablation using CT image integration into an electroanatomic mapping system. CT registration using the pulmonary veins as markers (landmark) was achieved with an error of 6.4 +/- 2.8 mm with repeat registration required in two patients. Registration of the CT by best fit to a electroanatomic geometry (surface) was achieved with an error of 2.3 +/- 0.4 mm. There was no significant difference in the regional LA registration error at superior (1.7 +/- 0.7 mm), inferior (2.2 +/- 1.4 mm), septal (1.7 +/- 0.8 mm), and lateral (1.7 +/- 0.7 mm, P = 0.13) sites. Cardiac rhythm at the time of CT did not have a significant effect on total or regional surface registration accuracy (mean total 2.5 +/- 0.3 in AF patients vs 2.3 +/- 0.5 in SR patients, P = 0.22). The integrated CT was used to guide the encirclement of the pulmonary veins (PV) in pairs with electrical isolation achieved by maintaining ablation along the ablation line in 58 of 60 PV pairs. Postprocedural PV angiography did not demonstrate significant stenosis. CONCLUSION: CT image integration into an EAM system was successfully performed in patients undergoing catheter ablation for AF. With a greater appreciation of the complex and variable nature of the PV and LA anatomy this new technology may improve the efficacy and safety of the procedure.     

Elimination of focal atrial fibrillation with a single radiofrequency ablation: use of a basket catheter in a pulmonary vein for computerized activation sequence mapping

A focal source for atrial fibrillation (AF) may be found in the first few centimeters of the pulmonary veins. Radiofrequency (RF) ablation may be directed at this source using activation mapping, but if the responsible atrial extrasystoles are infrequent or difficult to map, elimination of the source may require complete electrical isolation of the vein with multiple RF lesions. A new three-dimensional mapping system using a 64-pole basket catheter has been developed recently. We report the use of this system for ablation of focal AF in two patients. Mapping identified foci in the left and right superior pulmonary veins. Each focus was eliminated with a single RF ablation.