Radiofrequency catheter ablation within the coronary sinus eliminates a macro-reentrant atrial tachycardia: Importance of mapping in the coronary sinus

We describe a patient who underwent radiofrequency (RF) catheter ablation of symptomatic atrial fibrillation. After left atrial (LA) catheter ablation and pulmonary vein isolation, a macro-reentrant atrial tachycardia (AT) with a critical isthmus at the mitral isthmus was induced by incremental atrial pacing from the coronary sinus. Extensive RF energy applications from endocardial sites using ablation catheters with 4 mm- and 8 mm- tips resulted in no discrete potentials being recorded from the endocardial sites of the isthmus, but the tachycardia could not be terminated. However, discrete potentials were recorded within the CS, and epicardial RF energy applications from the CS eliminated the tachycardia. Thus, mapping in the CS is useful for detecting residual conduction at epicardial sites along the mitral isthmus. RF catheter ablation within the CS should be considered when no distinct electrograms are recorded after extensive ablation from the endocardial sites and when distinct electrograms are recorded within the CS.     

New Mapping Technology for Atrial Tachycardias

Prerequisite for succesful radiofrequency catheter ablation of tachycardias is the exact mapping during the electrophysiological study. The new mapping system CARTO allows a three-dimensional color-coded electroanatomic map of impulse propagation using electromagnetic technology. The aim of this study was to determine the feasibility and safety of the new electromagnetic mapping technology CARTO for atrial tachycardias.Results: Electrophysiologic study and CARTO mapping was performed in 38 atrial tachycardias. The mapping procedure took 26 ± 23 min. We created 33 maps within the right atrium and 5 maps within the left atrium with a mean of 74 ± 38 different catheter positions. The mechanism was determined as reentrant in 9, junctional in 1 and focal in 28 tachycardias. In focal tachycardias the tachycardia cycle length (CL) and the total atrial activation time (AT) were clearly different (352 ± 98 ms vs 99 ± 25 ms). Reentrant tachycardias had a comparable CL and AT (236 ± 44 ms vs 240 ± 56 ms). In 83% of the focal tachycardias and in 67% of the reentrant tachycardias, ablation was performed successfully. No complications occured.Conclusion: The electroanatomic mapping system allows high resolution visualization of electrical activity and may therefore improve precision and simplify the determination of the arrhythmogenic substrate during tachycardias for successful catheter ablation.     

三维标测指导下射频导管消融右心耳起源的局灶性房性心动过速

目的 报道应用三维标测指导射频导管消融起源于右心耳的局灶性房性心动过速(房速),并初步探讨其临床及心电学特征.方法 共6例患者(男性4例,女性2例,年龄(43±19)岁]临床诊断为窄QRS心动过速,其中3例曾行常规射频消融失败,4例左心房内径明显扩大.经电生理检查证实为房速.术中行EnSite-NavX激动标测或者Carto电解剖标测以明确局灶性房速并指出最早激动大致范围.在局部做精细标测找到心房最早激动处,于心动过速时应用盐水灌注导管放电消融,能量30～40 W,温度43℃.即刻成功指标为心动过速终止并不再被诱发.结果 6例心动过速平均心动周期为(343±53)ms.三维激动标测结果显示房速呈右心耳部位点状扩布,并且整个右心房激动时间占心动周期的27%±8%.成功消融靶点局部A波较体表心电图P波提前(52±13)ms.消融后行右心房心耳造影确认消融导管位置.6例右心耳房速均成功消融且未有并发症发生.随访3个月其中1例复发心动过速,经再次标测证实为三尖瓣前侧部局灶性房速并且成功消融.左心房扩大者心房内径较术前显著缩小[(41±6)mm对(36±6)mm,P＜0.05].结论 局灶性房速可起源于右心耳并可以成功消融.三维标测有助于靶点定位及消融成功.     

心房颤动环肺静脉隔离术后复发左房房性心动过速的特点及消融治疗

目的探讨心房颤动(简称房颤)环肺静脉隔离术后(CPVI)复发左房房性心动过速(简称房速)再次射频消融中,房速机制的鉴别和消融策略的选择。方法18例房颤经CPVI术后复发房速患者,其中男16例,女2例,年龄61.4±6.5(50～70)岁。在持续稳定的自发/诱发房速时在Carto指导下行激动顺序标测,经电生理检测,明确房速机制并选择相应消融方式:对于局灶性房速,重新阻断原消融径线上裂隙或消融最早激动区;对于折返性房速,明确关键峡部,行线性消融,如果有肺静脉电位亦行对裂隙的消融。结果共有13例肺静脉恢复电活动(72.7%)。局灶性房速6例,折返性房速12例(包括11例左房大折返和1例肺静脉-左房折返)。相应方式消融后房速均转为窦性心律,且肺静脉电位消失。结论房颤CPVI术后复发的左房房速与肺静脉电位的恢复密切相关;与消融线和裂隙形成的折返有关。     

Left atrial tachycardia after circumferential pulmonary vein ablation for atrial fibrillation: electroanatomic characterization and treatment.

OBJECTIVES: The purpose of this study was to evaluate the electroanatomic characteristics of left atrial tachycardia (AT) in a series of patients who underwent circumferential pulmonary vein ablation (CPVA) and to describe the ablation strategy and clinical outcome. BACKGROUND: Circumferential pulmonary vein ablation is an effective treatment for atrial fibrillation. A potential midterm complication is the development of left AT. There are only isolated reports describing mapping and ablation of such arrhythmias. METHODS: Thirteen patients (age 57.4 +/- 8.9 years, five female) underwent mapping and ablation of 14 left ATs via an electroanatomic mapping system a mean of 2.6 +/- 1.6 months after CPVA. RESULTS: Three patients were characterized as having focal AT (cycle length: 266 +/- 35.9 ms). Of 11 macro-re-entrant tachycardias studied in the remaining 10 patients (cycle length: 275 +/- 75 ms), 5 showed single-loop and 6 dual-loop circuits. Re-entrant circuits used the mitral isthmus, the posterior wall, or gaps on previous encircling lines. Such gaps and all three foci occurred anterior to the left superior pulmonary vein or at the septal aspect of the right pulmonary veins. Thirteen of 14 tachycardias (93%) were successfully ablated. CONCLUSIONS: Left AT after CPVA can be due to a macro-re-entrant or focal mechanism. Re-entry occurs most commonly across the mitral isthmus, the posterior wall, or gaps on previous ablation lines. Such gaps and foci occur most commonly at the anterior aspect of the left superior pulmonary vein and at the septal aspect of the right pulmonary veins. These arrhythmias can be successfully mapped and ablated with an electroanatomic mapping system.     

慢性心房颤动消融术后房性心动过速的机制和消融治疗

目的 探讨慢性心房颤动(房颤)环肺静脉消融术后房性心动过速(房速)的机制及射频消融的方法.方法 慢性房颤消融术后房速患者9例,均为男性,年龄50～70(62.6±7.2)岁.在三维标测系统和环状标测导管联合指导下,对无心房-肺静脉电传导者的房速经标测在关键峡部消融;对存在心房一肺静脉电传导者的房速,在原消融径线上的裂隙处消融.结果 3例为无心房-肺静脉点传导的折返性房速,于关键峡部线性消融后房速终止;6例为存在心房-肺静脉电传导的房速,对原消融径线裂隙消融后,4例房速终止,余2例附加左心房峡部线性消融后房速亦终止.消融术时间为90～295(211.7±75.4)min,X线曝光时间为11.5～67.6(25.5±16.5)min.消融术后各种刺激亦均不能诱发房速,没有出现肺静脉狭窄和其他相关并发症.随访4～8(6.2±1.4)个月,9例患者停用抗心律失常药物后仍为窦性心律.结论 慢性房颤消融术后恢复心房-肺静脉电传导的房速(66.7%)占大多数;无心房-肺静脉电传导的房速多为折返机制;针对恢复传导部位的补点式消融和对折返环关键峡部的线性消融,可以成功终止并发的房速.     

Initial experience in the use of integrated electroanatomic mapping with three-dimensional MR/CT images to guide catheter ablation of atrial fibrillation

INTRODUCTION: No prior studies have reported the use of integrated electroanatomic mapping with preacquired magnetic resonance/computed tomographic (MR/CT) images to guide catheter ablation of atrial fibrillation (AF) in a series of patients. METHODS AND RESULTS: Sixteen consecutive patients with drug-refractory AF underwent catheter ablation under the guidance of a three-dimensional (3D) electroanatomic mapping system (Carto, Biosense Webster, Inc., Diamond Bar, CA, USA). Gadolinium-enhanced MR (n = 8) or contrast-enhanced high-resolution CT (n = 8) imaging was performed within 1 day prior to the ablation procedures. Using a novel software package (CartoMerge, Biosense Webster, Inc.), the left atrium (LA) with pulmonary veins (PVs) was segmented and extracted for image registration. The segmented 3D MR/CT LA reconstruction was accurately registered to the real-time mapping space with a combination of landmark registration and surface registration. The registered 3D MR/CT LA reconstruction was successfully used to guide deployment of RF applications encircling the PVs. Upon completion of the circumferential lesions around the PVs, 32% of the PVs were electrically isolated. Guided by a circular mapping catheter, the remaining PVs were disconnected from the LA using a segmental approach. The distance between the surface of the registered 3D MR/CT LA reconstruction and multiple electroanatomic map points was 3.05 +/- 0.41 mm. No complications were observed. CONCLUSIONS: Three-dimensional MR/CT images can be successfully extracted and registered to anatomically guided clinical AF ablations. The display of detailed and accurate anatomic information during the procedure enables tailored RF ablation to individual PV and LA anatomy.     

Disparate activation of the coronary sinus and inferior left atrium during atrial tachycardia after persistent atrial fibrillation ablation: prevalence, pitfalls, and impact on mapping

Partial Coronary Sinus Disconnection During Atrial Tachycardia . Introduction: Persistent atrial fibrillation (AF) ablation may lead to partial disconnection of the coronary sinus (CS). As a result, disparate activation sequences of the local CS versus contiguous left atrium (LA) may be observed during atrial tachycardia (AT). We aimed to evaluate the prevalence of this phenomenon and its impact on activation mapping. Methods: AT occurring after persistent AF ablation were investigated in 74 consecutive patients. Partial CS disconnection during AT was suspected when double potentials with disparate activation sequences were observed on the CS catheter. Endocardial mapping facing CS bipoles was performed to differentiate LA far‐field from local CS potentials. Results: A total of 149 ATs were observed. Disparate LA–CS activations were apparent in 20 ATs after magnifying the recording scale (13%). The most common pattern (90%) was distal to proximal endocardial LA activation against proximal to distal CS activation, the latter involving the whole CS or its distal part. Perimitral macroreentry was more common when disparate LA–CS activations were observed (67% vs 29%; P = 0.002). Partial CS disconnection also resulted in “pseudo” mitral isthmus (MI) block during LA appendage pacing in 20% of patients as local CS activation was proximal to distal despite distal to proximal activation of the contiguous LA. Conclusion: Careful analysis of CS recordings during AT following persistent AF ablation often reveals disparate patterns of activation. Recognizing when endocardial LA activation occurs in the opposite direction to the more obvious local CS signals is critical to avoid misleading interpretations during mapping of AT and evaluation of MI block. (J Cardiovasc Electrophysiol, Vol. 23, pp. 697‐707, July 2012)     

Ventricular location of a part of the right atrial isthmus after tricuspid valve replacement for Ebstein’s anomaly: a challenge for atrial flutter ablation

We report the case of a patient with atrial flutter late after tricuspid valve replacement for Ebstein’s anomaly. Computed tomographic angiography revealed that coronary sinus ostium and part of the right atrial isthmus were located on the ventricular side of the valve ring due to the specific surgical approach in this condition. Based on the results of electroanatomic mapping and entrainment, the arrhythmia was found to be cavotricuspid isthmus dependent clockwise atrial flutter. Completion of the isthmus line required ablation lesions across the artificial valve. When these were delivered the arrhythmia terminated and isthmus block was achieved. Due to arrhythmia recurrence a redo procedure was performed which demonstrated conduction recovery in the ventricular part of the cavotricuspid isthmus. Intracardiac ultrasound-guided ablation successfully eliminated conduction across the isthmus with subsequent freedom from arrhythmia on follow up.     

CARTO标测指导射频消融治疗非峡部依赖性心房扑动的初步研究

初步探讨非峡部依赖性心房扑动 (简称房扑 )———非典型房扑CARTO标测的方法学和射频消融效果。 4例经电生理标测证实的非典型房扑患者 ,男、女各 2例 ,年龄 2 4～ 5 7岁。 1例为先天性心脏病 (简称先心病 )三房心外科术后 ,1例为慢 快综合征。房扑发作时在右房或左房CARTO标测 ,三维重建右房或左房 ,寻找房扑折返径路的关键峡部区域行线性消融。结果 :3例为右房非峡部依赖性房扑 ,1例消融径线为 2条 ,即三尖瓣环至下腔静脉(IVC)口和右房后外侧至IVC ,1例消融径线为右房前中外侧 ,1例为右房下外侧。 1例左房房扑 ,消融径线位于右上肺静脉口下方至卵园窝。 4例均即时消融成功。随访 8～ 2 4个月 ,有 1例先心病术后房扑复发 ,再次行CARTO标测发现房扑折返环位于左房 ,划线消融未成功。结论 :CARTO标测非峡部依赖性房扑有一定的优势 ,能显示房扑折返环和关键峡部 ,并能指导线性消融     

Randomized comparison of anatomical versus voltage guided ablation of the cavotricuspid isthmus for atrial flutter.

OBJECTIVES: The purpose of this prospective study was to compare radiofrequency catheter ablation of the cavotricuspid isthmus using a strictly anatomic approach to an approach guided by a bipolar voltage map to avoid high voltage zones in the cavotricuspid isthmus. BACKGROUND: It is not clear whether local atrial electrogram amplitude influences the achievement of complete cavotricuspid isthmus block during radiofrequency catheter ablation for atrial flutter. METHODS: Thirty-two patients with atrial flutter were randomized to cavotricuspid isthmus ablation using an anatomical approach (group I, 16 patients) or guided by a bipolar voltage map (group II, 16 patients). A 3-dimensional electroanatomic mapping system and an 8-mm-tip ablation catheter were used in all patients. With the anatomical approach, an ablation line was created in the cavotricuspid isthmus at a 6 o'clock position in the 45 degree left anterior oblique projection. During voltage-guided ablation, a high-density bipolar voltage map of the cavotricuspid isthmus was created, and then contiguous applications of radiofrequency energy were delivered to create an ablation line through the cavotricuspid isthmus sites with the lowest bipolar voltage. RESULTS: Complete cavotricuspid isthmus conduction block was achieved in 100% of patients in each group. The mean maximum voltages along the line were 3.6 +/- 1.5 mV in group I, and 1.2 +/- 0.9 mV in group II (P < .01). Creating a high-density voltage map was associated with approximately 15-minute increase in the total procedure time (P = .2). During a mean follow-up of 177 +/- 40 days, there were no recurrences of atrial flutter in either group. There were no complications in either group. CONCLUSIONS: When cavotricuspid isthmus ablation for atrial flutter is performed with an 8-mm-tip catheter, complete block can be achieved in all patients regardless of local voltage. Ablation of high voltage zones is not associated with a higher recurrence rate. Therefore, anatomic ablation without voltage mapping is the preferred initial approach for cavotricuspid isthmus ablation.     

Carto 3指导阵发性房颤的导管消融

目的探讨Carto 3系统指导下,其对于阵发性房颤导管消融有效性及优势性所在;方法利用Carto 3系统构建左房三维电解剖模型,在Carto 3指导下行环肺静脉线性消融;结果在本研究中,6例患者采用Lasso导管运用Carto3快速解剖建模方式构建左房模型,20例患者采用消融电极（MAP）重建左房模型。左房建模时间为12.8±3.3分钟,所有患者均完成环肺静脉电隔离术,无严重并发症出现。结论运用Carto3快速解剖建模方式可建立媲美CT的高精度解剖模型,CARTO 3系统的导管实时可视化功能可提供心腔内精确的电极位置,保证导管可及时准确的到位。     

Mechanisms of right atrial tachycardia occurring late after surgical closure of atrial septal defects

Postatriotomy atrial tachycardia ablation. INTRODUCTION: In patients without structural heart disease, the most frequently occurring AT is the common atrial flutter. In patients with repaired congenital heart disease other mechanisms of AT may occur, due to the presence of an atriotomy that can provide a substrate for reentry. The aim of the present study was to identify the mechanisms of atrial tachycardia (AT) occurring late after atrial septum defect (ASD) repair, with the help of a three-dimensional electroanatomical mapping system. METHODS AND RESULTS: Twenty-two consecutive patients presenting with AT underwent complete electroanatomic mapping (CARTO, Biosense Webster, Diamond Bar, CA) of spontaneously occurring and inducible right ATs. Complete maps of 26 ATs were obtained. Three tachycardia mechanisms were identified: single-loop macroreentrant atrial tachycardia (MAT) (n=7), double-loop MAT (n=18), and focal AT (n=1). In all MATs, protected isthmuses were identified as the electrophysiological substrate of the arrhythmia, most frequently the cavotricuspid isthmus (CTI) (n=24), and a gap between the inferior vena cava and a line of double potentials (n=11). A mean number of 13.5+/-2.1 radiofrequency applications were delivered to transect these critical parts of the circuit. During a follow-up of 25+/-16 months the RF ablation was acutely successful in all patients. Thirteen patients (59%) had an early recurrence of MAT and needed an additional ablation procedure. One of those patients needed two additional ablation procedures. CONCLUSIONS: Three-dimensional electroanatomic mapping is useful to identify postsurgical AT mechanisms; the CTI isthmus is involved in 92% MAT, and if the right atrial free wall (RAFW) abnormal tissue related to surgical scar is present this substrate contributes to the MAT circuit.     

心脏外科手术后房性心律失常的三维电解剖标测和射频消融

目的应用Carto系统对心脏外科手术后房性心律失常患者进行三维电解剖标测和射频消融。方法入选心脏外科手术后房性心律失常患者29例,平均年龄（47±13）岁,男性15例,女性14例。在心动过速时,电解剖标测三维重建右心房和／或左心房。根据双极电图电压确定瘢痕区。对于折返性房性心动过速（房速）,线性消融关键峡部或瘢痕区与正常解剖障碍区之间或两瘢痕区间,对于局灶性房速,点消融局部最早激动区域。结果29例患者中,共标测39种心动过速,右心房切口性房速13例（45％）,右心房峡部心房扑动（房扑）19例（66％）,其中单一出现患者11例（38％）,伴发出现患者8例（28％）,即时消融成功率93％（27／29）,无消融术相关并发症发生。随访（26±20）个月,2例复发,1例再次消融成功。结论心脏外科手术后房性心律失常常见为右心房切口性房速和右心房峡部房扑,Carto电解剖标测系统可有效指导射频消融治疗。     

Catheter ablation of long-lasting persistent atrial fibrillation: critical structures for termination

BACKGROUND: The relative contributions of different atrial regions to the maintenance of persistent atrial fibrillation (AF) are not known. METHODS: Sixty patients (53 +/- 9 years) undergoing catheter ablation of persistent AF (17 +/- 27 months) were studied. Ablation was performed in a randomized sequence at different left atrial (LA) regions and comprised isolation of the pulmonary veins (PV), isolation of other thoracic veins, and atrial tissue ablation targeting all regions with rapid or heterogeneous activation or guided by activation mapping. Finally, linear ablation at the roof and mitral isthmus was performed if sinus rhythm was not restored after addressing the above-mentioned areas. The impact of ablation was evaluated by the effect on the fibrillatory cycle length in the coronary sinus and appendages at each step. Activation mapping and entrainment maneuvers were used to define the mechanisms and locations of intermediate focal or macroreentrant atrial tachycardias. RESULTS: AF terminated in 52 patients (87%), directly to sinus rhythm in 7 or via the ablation of 1-6 intermediate atrial tachycardias (total 87) in 45 patients. This conversion was preceded by prolongation of fibrillatory cycle length by 39 +/- 9 msec, with the greatest magnitude occurring during ablation at the anterior LA, coronary sinus and PV-LA junction. Thirty-eight atrial tachycardias were focal (originating dominantly from these same sites), while 49 were macroreentrant (involving the mitral or cavotricuspid isthmus or LA roof). Patients without AF termination displayed shorter fibrillatory cycles at baseline: 130 +/- 14 vs 156 +/- 23 msec; P = 0.002. CONCLUSION: Termination of persistent AF can be achieved in 87% of patients by catheter ablation. Ablation of the structures annexed to the left atrium-the left atrial appendage, coronary sinus, and PVs-have the greatest impact on the prolongation of AF cycle length, the conversion of AF to atrial tachycardia, and the termination of focal atrial tachycardias.     

Non-Contact-Mapping des linken Vorhofs mittels Multielektroden-Ballonkatheter

In contrast to the sequential mapping systems such as the conventional and the electroanatomic mapping, the non-contact mapping provides simultaneous mapping. The non-contact-mapping system detects far-field endocardial potentials from a multielectrode-array catheter and reconstructs over 3,000 unipolar virtual electrograms. Based on the virtual electrograms, the system produces an instantaneous three-dimensional (3-D) isopotential map. High-density mapping of the endocardial activation sequence allows immediate and simultaneous identification of a propagation vector along the line and the identification of an arrhythmogenic focus on a single beat. The methods and results of different ablation strategies for atrial fibrillation using the non-contact-mapping system are reported.     

Epicardial‐endocardial breakthrough site ablation: Demonstration of alternative target for perimitral atrial tachycardia

A 62‐year‐old man underwent the catheter ablation for persistent atrial tachycardia (AT) with a cycle length of 357 milliseconds. An ultrahigh resolution mapping revealed that this tachycardia was a clockwise perimitral AT despite the conduction was apparently blocked across the lateral mitral isthmus line both at the endocardium and within the coronary sinus. The AT was terminated by the single radiofrequency application at the site below the mitral isthmus line where the endocardial activation breakout was seen. This case suggests that the epicardial‐endocardial conduction breakthrough site may be an alternative ablation target in a difficult ablation case of perimitral AT.     

Electrophysiologic and clinical consequences of linear catheter ablation to transect the anterior left atrium in patients with atrial fibrillation

OBJECTIVES: To evaluate the feasibility and outcome of ablation to transect the anterior left atrium (LA) in patients with atrial fibrillation (AF). BACKGROUND: While the Maze procedure is effective in maintaining sinus rhythm in patients with AF, it is associated with significant morbidity. This prospective clinical study evaluates the feasibility and consequences of limited LA linear ablation to transect the anterior LA in patients with AF. METHODS: Twenty-four patients (51.2 +/- 7.3 years) with paroxysmal (n = 16) or chronic (n = 8) AF resistant to pulmonary vein (PV) isolation were studied. To transect the anterior LA, linear ablation was performed joining the superior PVs; this line was then connected to the anterior mitral annulus. Pulmonary vein isolation and cavotricuspid isthmus ablation were performed in all cases. Ablation was performed using an irrigated catheter with the endpoint of achieving complete linear block demonstrated by online double potentials, differential pacing techniques, and an activation detour. RESULTS: Of 20 patients in AF prior to linear ablation, arrhythmia terminated in 12 (60%), including half the patients with chronic AF, during ablation. Despite repeated ablation, complete linear block was achieved in only 14 of 24 patients (58%). Complete linear conduction block resulted in an activation detour around the mitral annulus and PVs with a delay of 158 +/- 30 ms (P = .0001), significantly delayed activation of the lateral LA with prolongation of P-wave duration (P = .002), and characteristic change in P-wave morphology during sinus rhythm (P = .002). Of the 14 with anterior LA transection, 4 (29%) have had regular atrial tachycardias due to macroreentry through recovered gaps. Nine of these 14 (64%) have remained arrhythmia-free without antiarrhythmics compared to 3 of 10 (30%) with incomplete block at 28 +/- 4 months following their last procedure (P = .2). CONCLUSIONS: This study demonstrates the feasibility of catheter ablation to transect the anterior LA in humans. While being effective in the termination of AF, this configuration of linear lesions is technically challenging to complete, results in significant delayed LA activation, and is associated with modest long-term arrhythmia suppression.     

Mapping and ablation of atrial arrhythmia after valve surgery plus mini-maze procedure

Background Recurrent atrial arrhythmia is very common in patients after mitral valve surgery plus mini-maze procedure.Investigation about the mechanism for these patients may have important implication to improve the surgery strategy.Methods Mini-maze procedure was defined as follow: Pulmonary vein encircling incision and roof line connecting the two circles lesion,left atrial isthmus lesion,and the right atrial isthmus lesion.There were 517 patients with rheumatic valvular disease and pre-operative atrial fibrillation (AF) undergoing valve surgery plus mini-maze procedure in our hospital in the last 3 years,and 93 patients(18%) had recurrent atrial arrhythmia.Twelve patients(6 males and 6 females,mean age 53.8±7.8 ys) underwent electrophysiological study using 3-D mapping system(10 pts) or conventional mapping method(2 pts).Results The first recurrent time from surgery was 4.4±2.2 months.The mean follow-up time after catheter ablation was(12.0±6.0) months.One patient with sinus bradycardia had recurrent incessant atrial tachycardia (AT),but the AT was terminated by catheter position and never could be induced any more.She underwent a repeat procedure but failed just as the course in the first time, and was treated with DDDR pacemaker plus amiodarone.Six patients had 10 kinds of stable AT,including 5 at right atrial isthmus,2 at roof line,1 related to right atrial incision, 1 at anterior wall of left atrial,and 1 related to left superior pulmonary vene.All the stable AT were eliminated and remained sinus rhythm.Three patients had ATs with variable cycle length and the 3-D mapping suggested macro-reentry AT around mitral annulus.We tried to ablate at routine mitral isthmus and also in coronary sinus,but could not reach bi-directional conduction blocking.The other 2 patients were AF with reconnection at all previous ablation sites.Ablation strategy for AF included lesion at re-conduction sites and complex fractionated atrial electrogram.The patients with AF and mitral isthmus related AT were administrated with     

高密度标测指导下射频导管消融房性心动过速

目的 探讨EnSite NavX系统高密度标测对房性心动过速（房速）射频导管消融的指导作用.方法 17例房速患者,平均年龄（45.9±16.9）岁,男性15例,女性2例.心动过速均呈持续性发作,应用EnSite NavX系统于心房进行高密度标测,建立激动图.对于折返性房速,线性消融关键峡部或传导通道（channel）,对于局灶性房速,点消融局部最早心房激动区域.结果 17例患者中,共标测到19种房速,周长为（254±49）ms,平均取点（316±90）个,标测时间为（8.4±2.6）min,建立19种激动图 激动图显示大折返性房速10种,局灶性房速9种 19种房速中,18种即时消融成功 无标测与消融相关并发症发生.随访（3.0±1.6）个月,2例服用胺碘酮可预防发作（1例患者房速复发,1例患者术中有1种房速未消融成功）.结论 EnSite NavX系统高密度标测对心动过速机制可作出快速、准确的判断,有助于确定消融靶点,提高消融成功率.