先天性心脏病术后下腔静脉口-三尖瓣环峡部依赖性心房扑动的导管消融疗效分析

目的:报道先天性心脏病术后下腔静脉口-三尖瓣环峡部依赖性心房扑动的相对发生率及导管消融的疗效和安全性。方法:选择2002年1月-2006年4月在我院因先天性心脏病术后心房内折返性心动过速行射频消融的40例患者,应用常规电生理标测方法或三维标测方法(Carto和Ensite)指导导管消融,观察下腔静脉口-三尖瓣环峡部心房扑动相对发生率及其导管消融结果。结果:40例患者共诱发出50种房性心动过速,具有典型下腔静脉口-三尖瓣环峡部依赖性心房扑动心电图表现,且成功靶点在下腔静脉口和三尖瓣环峡部者31种(31／50,62．0％)。另外19种(19／50,38．0％)房性心动过速临床心电图表现与典型心房扑动不同,表现为P’波,其中11种(11／50,22．0％)成功靶点在右心房游离壁疤痕-下腔静脉峡部,瘢痕-上腔静脉峡部者2种,瘢痕与瘢痕之间峡部者2种;在瘢痕和三尖瓣环之间2种。房间隔补片和上腔静脉之间、房间隔补片和三尖瓣环之间各消融成功1种。40例患者射频消融成功,无并发症。随访1例患者心动过速复发,二次消融成功;1例患者出现持续性心房颤动伴RR长间歇,植入永久性起搏器。结论:先天性心脏病术后心房内折返性心动过速常常为下腔静脉口-三尖瓣环峡部心房扑动,导管消融具有较高的疗效和安全性。     

射频导管消融典型心房扑动和手术疤痕折返性房性心动过速共存一例

典型心房扑动(房扑)的成功消融部位是右心房的先天性峡部(三尖瓣环-下腔静脉峡部)，而对于手术疤痕折返性房性心动过速(疤痕折返性房速)，消融部位则是与手术疤痕相关的后天性峡部。本文报道1例共存有上述两种心动过速患者的成功消融过程。     

非接触心内膜激动标测系统指导房间隔缺损修补术后Ⅱ型心房扑动的射频消融(附一例报道)

评价非接触球囊导管标测系统 (EnSite 30 0 0 )在指导房间隔缺损 (ASD)修补术后心房扑动 (简称房扑 )的射频消融中的临床应用。 1例女性患者 ,41岁 ,ASD修补术后 2 2年开始频繁发作心动过速 ,体表心电图示Ⅱ型房扑。应用EnSite 30 0 0构建右房三维几何模型 ,标测心动过速的折返激动顺序 ,发现手术疤痕与三尖瓣环之间、下腔静脉与三尖瓣环之间为折返环路的关键峡部 ,应用导航系统指导峡部消融 ,成功阻断心动过速 ;消融后通过起搏标测判定峡部已达完全双向阻滞。随访 2 0个月 ,无心动过速复发。结论 :在ASD修补术后房扑的标测和消融中应用EnSite30 0 0系统是安全有效的 ,不仅能确定折返环路的关键峡部 ,而且能准确判断线性损伤的连续性。     

先天性心脏病术后心房内折返性心动过速的射频消融

先天性心脏病术后常常发生心房内折返性心动过速(IART)而且治疗困难。本研究的目的是观察疤痕下方2下腔静脉开口或/和下腔静脉2三尖瓣环峡部消融的疗效。11例患者12种房性心动过速进行电生理检查和射频消融。在双电位区域仔细寻找碎裂电位和A波最早处为消融开始的靶点,并向自身解剖形成的传导障碍区延伸。结果:10例11种房性心动过速射频消融成功,成功率为11/12(91.7%),8种心动过速的成功靶点位于右心房外侧壁疤痕下方,3例为典型心房扑动的峡部。平均放电次数为5±4次。随访17±6个月,10例无心动过速发作。结论:疤痕2下腔静脉之间或/和下腔静脉2三尖瓣峡部消融可以有效的消除先天性心脏病术后的IART。     

非接触心内膜激动标测系统指导房间隔缺损修补术后H型心房扑动的射频消融（附一例报道）

评价非接触球囊导管标测系统(EnSite 3000)在指导房间隔缺损(ASD)修补术后心房扑动(简称房扑)的射频消融中的临床应用。1例女性患者，41岁，ASD修补术后22年开始频繁发作心动过速，体表心电图示H型房扑。应用EnSite 3000构建右房三维几何模型，标测心动过速的折返激动顺序，发现手术疤痕与三尖瓣环之间、下腔静脉与三尖瓣环之间为折返环路的关键峡部，应用导航系统指导峡部消融，成功阻断心动过速；消融后通过起搏标测判定峡部已达完全双向阻滞。随访20个月，无心动过速复发。结论：在ASD修补术后房扑的标测和消融中应用EnSite 3000系统是安全有效的，不仅能确定折返环路的关键峡部，而且能准确判断线性损伤的连续性。     

儿童室间隔修补术后远期心房内折返性心动过速的消融

目的报道儿童先天性心脏病室间隔缺损（VSD）术后远期出现的心房内折返性心动过速（IART）的电生理标测及导管消融疗效。方法8例患儿（男、女各4例）,平均年龄（7．1±4．1）岁,VSD术后1～5年发生持续性IART,8例均有左心室扩大,其中5例合并慢性心力衰竭。行心房电生理标测,部分应用三维标测（EnSiteNavX）技术,标测折返环的关键峡部并行导管消融。结果8例均自发IART,折返环关键部位分布：6例位于三尖瓣环峡部,1例于右心房界嵴至下腔静脉间,1例于三尖瓣环9点位置至界嵴问。所有（100％）患儿手术即刻成功,无并发症。平均随访（25．2±16．5）个月,2例复发,其中1例再次消融成功,总成功率7／8（87．5％）。左心室人小及射血分数均明显好转。结论儿童VSD术后IART机制多为三尖瓣环一下腔静脉峡部依赖型心房扑动,可经导管消融治愈或明显改善。三维标测技术能准确快速定位折返环的电生理峡部并指导消融,显著减少曝光时间。     

Carto标测指导导管消融心脏病术后心房内折返性心动过速

目的：心脏外科术后的心房折返性心动过速（IART）折返环涉及无传导的或各向异性的传导障碍区，本研究的目的是利用三维电解剖标测系统（Carto）标测这些障碍区并确定与折返环的关系，指导导管消融。方法：22例患者共26种IART进行了Carto标测，首先确定形成IART的基质以及与折返环的关系，并在其峡部消融。结果：22例患者诱发出27种心动过速，对其中26种进行标测，12种IART中心障碍区为三尖瓣环，其消融靶点在下腔静脉一三尖瓣环峡部；12种IART中心障碍区在右心房游离壁，其消融靶点在其周围；2种IART中心障碍区在房间隔，并在此障碍区下方消融成功。即刻成功21例，其中峡部消融成功者12例、游离壁消融成功者7例、间隔部消融成功者2例。平均随访（22±7）个月，20例无心律失常发生而不需用药。结论：可以利用三维电解剖标测方法标测IART基质，这些基质构成IART的中心传导障碍区，消融靶点常常位于其周围。     

慢传导带传导阻滞和为心房扑动消融终点的意义

应用Ｈａｌｏ导管标测技术，结合冠状动脉窦与希氏束电图识别心房扑动折返环的慢传导带，在下腔静脉口到三尖瓣环峡部作射频线性消融，并以慢传导带出现双向阻滞作为心房扑动消融成功的标志，治疗了１例Ｉ型心房扑动患者。随访１个月心动过速未发。     

大折返房性心动过速的电解剖标测和导管射频消融

目的应用电解剖标测系统分析3例大折返房性心动过速(房速)的电生理机制并导航消融。方法3例房速患者(男1例,女2例),平均年龄51±12岁,心动过速病史19±11年。常规电生理检查初步确定房速所在心腔,使用电解剖标测系统构建心房三维模型,完成电压和激动标测,分析心动过速的机制并确定缓慢传导区(即关键峡部),使用冷生理盐水灌注导管消融。结果3例患者临床常规检查初步排除结构性心脏病,电压标测均显示被标测心房存在疤痕区。病例1为围绕三尖瓣环顺钟向的大折返房速,关键峡部位于三尖瓣环与后侧壁的疤痕之间。病例2为围绕上腔静脉逆钟向的大折返房速,关键峡部位于右房侧壁疤痕与上腔静脉之间。病例3为左房8字形折返,关键峡部位于左房顶部的两片疤痕之间。3例患者均在关键峡部消融成功,随访9～10个月未见复发。结论电解剖标测可以揭示大折返房速的基质,阐明折返机制,并有效指导消融。     

标测指导下点消融隔离三尖瓣环-下腔静脉峡部

目的自三尖瓣环至下腔静脉口线状消融隔离下腔静脉-三尖瓣环峡部是根治大折返环性心房扑动(简称房扑)的标准方法,但是这种方法消融点数多、消融径线盲目.标测指导下点消融隔离下腔静脉-三尖瓣环峡部无系统报告,本研究介绍采用这种方法隔离下腔静脉-三尖瓣环峡部的结果.     

Location of acutely successful radiofrequency catheter ablation of intraatrial reentrant tachycardia in patients with congenital heart disease

Intraatrial reentrant tachycardia (IART) is common after surgery for congenital heart disease (CHD). Radiofrequency (RF) catheter ablation of IART targets anatomic areas critical to the maintenance of the arrhythmia circuit, areas that have not been well defined in this patient population. The purpose of this study was to determine the anatomic areas critical to IART circuits, defined by activation mapping and confirmed by an acutely successful RF ablation at the site. A total of 110 RF ablation procedures in 88 patients (median age 23.4 years, range 0.1 to 62.7) with CHD were reviewed. Patients were grouped according to surgical intervention: Mustard/Senning (n = 15), other biventricular repaired CHD (n = 24), Fontan (n = 43), and palliated CHD (n = 6). In first-time ablation procedures, > or = 1 IART circuits were acutely terminated in 80% of Mustard/Senning, 71% of repaired CHD, and 72% of Fontan (p = NS). The palliated CHD group underwent 1 of 6 successful procedures (17%), and this patient was excluded. The locations of acutely successful RF applications in Mustard/Senning patients (n = 14 sites) were at the tricuspid valve isthmus (57%) and at the lateral right atrial wall (43%). In patients with repaired CHD (n = 18 sites), successful RF sites were at the isthmus (67%) and the lateral (22%) and anterior (11%) right atria. In the Fontan group (n = 40 sites), successful RF sites included the lateral right atrial wall (53%), the anterior right atrium (25%), the isthmus area (15%), and the atrial septum (7%). Location of success was statistically different for the Fontan group (p = .002). In conclusion, the tricuspid valve isthmus is a critical area for ablation of IART during the Mustard/ Senning procedure and in patients with repaired CHD. IART circuits in Fontan patients are anatomically distinct, with the lateral right atrial wall being the more common area for successful RF applications. This information may guide RF and/or surgical ablation procedures in patients with CHD and IART.     

Pericaval and periannular intra-atrial reentrant tachycardias in patients with congenital heart disease

INTRODUCTION: Intra-atrial reentrant tachycardia (IART) is a frequent late sequel of congenital heart surgery, often involving the cavotricuspid isthmus. In this report, we characterize pericaval reentry, a novel mechanism of isthmus-dependent IART in congenital heart patients, and compare its electrophysiologic characteristics with periannular atrial flutter. METHODS AND RESULTS: Electrophysiologic and electroanatomic mapping data and acute outcomes were reviewed in postoperative patients with congenital heart disease who underwent electrophysiologic study/radiofrequency catheter ablation at The Children's Hospital, Boston between January 1999 and November 2000. The study included all congenital heart patients with IART and who had undergone (1) the Fontan procedure and (2) a biventricular surgical repair other than atrial switch procedures. Thirty-seven IARTs were mapped in 22 Fontan patients. Twelve of 37 IARTs (33%) that revolved about the inferior vena cava (IVC) and involved the isthmus between the IVC and the tricuspid dimple/right-sided AV valve were identified in 12 patients (48%). Mean pericaval IART cycle length was 332 +/- 60 msec (range 240-410). An adjacent or surrounding area of scarring was observed in 10 of 12 IARTs. Slow zones (mean activation latency 39% +/- 11% IART cycle length) were detected in 8 of 12 circuits. The boundaries of the zone of slow conduction were scar-low crista (6) and scar-IVC (2). Periannular IART with CL 289 +/- 65 ms was observed in 14 of 20 patients with 4-chambered hearts. Slow zones (mean activation latency 28 +/- 9% IART cycle length) were found in 8 of 14 circuits. In both forms of IART, the predominant direction of activation of the isthmus was lateral to septal; 83% in pericaval IART and 87% in periannular IART. Radiofrequency catheter ablation successfully terminated 11 of 11 pericaval and 13 of 14 periannular IARTs. CONCLUSION: Pericaval reentry is a novel and ablatable mechanism of IART in patients specific to the Fontan procedure. It is distinguished from periannular atrial reentry by its association with Fontan anatomy, longer cycle lengths, and occurrence of a prominent discrete zone(s) of slow conduction. Both pericaval and periannular reentry show a marked preference for utilization of the isthmus in a lateral-to-septal direction.     

Catheter ablation of arrhythmias in ebstein's anomaly: a multicenter study

Catheter Ablation in Ebstein's Anomaly. Introduction: In patients with Ebstein's anomaly (EA) arrhythmias are frequently encountered. Although most arrhythmias can be targeted with catheter ablation, specific issues render the procedure more challenging in EA. This study examines the mechanisms of the different arrhythmias related to EA and the outcome after catheter ablation. Methods And Results: Clinical and procedural data of catheter ablation in patients with EA in 4 European centers were analyzed. In 32 patients (mean age 24 ± 15 years), 34 accessory pathways (APs), 8 intra‐atrial reentry tachycardias (IART), 5 cavotricuspid isthmus‐dependent atrial flutter (CTI‐AFL), 2 focal atrial tachycardias, and 1 atrioventricular nodal reentry tachycardia were ablated. In 11 patients (34%), multiple ablation targets were present. Eighteen patients (56%) required multiple procedures either for repeat ablation of the same arrhythmia (n = 12), ablation of a different arrhythmia (n = 4), or both re‐ablation of the same and of a different arrhythmia (n = 2). Procedural success rate after first ablation was 80% for APs and CTI‐AFL ablation, and 100% for IART ablation. Redo procedures were necessary in 40% of the patients after ablation of an APs, and in 60% after CTI‐AFL ablation, but in none of the patient with IART ablation. Conclusion: Most arrhythmias related to EA are amenable to catheter ablation. However, ablation procedures are challenging and the need for repeat procedure is particularly high, because some patients have multiple ablation targets and because of technical issues in relation with the dysplastic tricuspid annulus. In addition, several patients develop other arrhythmia mechanisms following ablation . (J Cardiovasc Electrophysiol, Vol. 22, pp. 1391‐1396, December 2011)     

Atypical Electrocardiographic Features of Cavotricuspid Isthmus‐Dependent Atrial Flutter Occurring during Left Atrial Fibrillation Ablation

Background: Patients who have undergone percutaneous catheter ablation for atrial fibrillation (AF) may develop cavotricuspid isthmus (CTI)‐dependent atrial flutter (AFL), which can occur either spontaneously during left atrial (LA) ablation for AF or by induction from sinus rhythm during the procedure. The electrocardiographic (ECG) characteristics of CTI‐dependent AFL occurring during LA ablation have not been described. The purpose of this study was to describe the ECG features of CTI‐dependent AFL occurring during percutaneous LA catheter ablation for AF. Methods and Results: Of 223 patients presenting for first AF ablation at our institution between May 2004 and February 2008, 20 patients (9%) developed CTI‐dependent AFL during LA ablation for AF. CTI‐dependent AFL developed spontaneously in 4 patients (20%) and was induced in 16 patients (80%). Among these 20 patients, 3 (15%) had typical ECG patterns and 17 (85%) had atypical ECG patterns. Flutter waves in the inferior leads were biphasic in 10 patients (50%), downward in 3 patients (15%), positive in 3 patients (15%), and not fitting the above classifications in 4 patients (20%). There was no statistically significant association between AFL pattern and LA size, left ventricular ejection fraction, total ablation time, duration of prior AF, or type of prior AF. Conclusion: A majority of patients with CTI‐dependent AFL occurring during LA ablation have atypical ECG patterns. Biphasic flutter waves in the inferior leads are common ECG features, occurring in one‐half of patients. Right atrial CTI‐dependent AFL should be suspected even if the ECG appearance is atypical. Ann Noninvasive Electrocardiol 2010;15(3):200–208     

Catheter tip cooling during radiofrequency ablation of intra-atrial reentry: effects on power,temperature, and impedance

INTRODUCTION: Cooling the catheter tip either passively with increased tip size or actively during radiofrequency catheter ablation (RFCA) has been shown in canine thigh preparations to create larger lesions than standard catheter tips, yielding a theoretical advantage for improving the outcome of RFCA for intra-atrial reentrant tachycardia (IART). METHODS AND RESULTS: The pediatric RFCA database at the Medical University of South Carolina was reviewed for RFCA of IART in patients with structural heart disease. From a total of 31 patients who underwent procedures during the study period, 8 patients in whom ablation with conventional ablation techniques failed and who went on to passive cooling with an 8-mm tip catheter or active cooling with an internally cooled-tip catheter were studied. Power delivery was greater but temperature and impedance were lower during cooled ablation than during conventional ablation. Passive cooling was associated with higher power than active cooling. These changes in RF biophysical characteristics were associated with successful elimination of 11 of 13 IART circuits in 7 of 8 patients. CONCLUSION: Cooling during RF ablation of atrial tachycardia clearly yielded greater power delivery in vivo and was associated with success.     

Correlation of atrial electrocardiographic amplitude with radiofrequency energy required to ablate cavotricuspid isthmus-dependent atrial flutter

OBJECTIVES: The purpose of this study was to evaluate a possible correlation between atrial ECG amplitude in common atrial flutter (AFL) and radiofrequency (RF) energy required to achieve cavotricuspid isthmus block. BACKGROUND: The amount of RF delivery required for ablation of typical AFL is variable. This variation has been attributed to the cavotricuspid isthmus anatomy. Atrial ECG amplitude can be a marker of atrial anatomic variations and therefore may correlate with RF duration required to achieve cavotricuspid isthmus block. METHODS: Seventy consecutive patients were prospectively studied. Ablation of the cavotricuspid isthmus was performed by creating a line of block between the inferior tricuspid annulus and the inferior caval vein using 8-mm-tip electrode catheters. If more than 20 minutes of RF time was required to achieve conduction block, the catheter was changed to an irrigated-tip catheter. Atrial ECG amplitude was assessed in leads II, III, aVF, and aVL. RESULTS: A total of 14 +/- 11 minutes of RF energy was delivered to achieve block in all patients; 12 patients (8%) required more than 20 minutes. Atrial ECG amplitude showed highly significant correlations with cumulative RF energy (F and P waves in lead II: r = 0.703 and r = 0.737, P < .001). P-wave amplitude <0.2 mV and/or flutter wave amplitude <0.35 mV in lead II have a high negative predictive value to predict <20 min RF delivery (96% and 89% respectively). CONCLUSIONS: A significant correlation exists between atrial ECG amplitude and amount of RF required to ablate typical AFL. Atrial ECG amplitude may be a surrogate marker of characteristics of isthmus anatomy. These findings may influence the choice of catheter used for cavotricuspid isthmus ablation.     

Mechanisms of atrial tachyarrhythmias following surgical atrial fibrillation ablation

INTRODUCTION: Typical and atypical atrial flutters (AFLs) and atrial tachycardias (ATs) have been reported in patients with prior surgical atrial fibrillation ablation. The underlying mechanisms for this group of atrial tachyarrhythmias have not been well characterized and the efficacy of catheter ablation in their treatment is unknown. METHODS AND RESULTS: Twenty patients (6 females) with a surface ECG diagnosis of AFL or AT following surgical atrial fibrillation ablation underwent 26 electrophysiology studies. Patients manifesting sustained, organized, and beat-by-beat reproducible atrial electrical activity underwent complete right and left atrial catheter mapping and catheter ablation. One patient had no inducible tachyarrhythmia, while 5 patients had nonmappable arrhythmias. Nineteen of the 31 potentially mappable atrial tachyarrhythmias were completely characterized in 14 patients. The underlying mechanisms were macro-reentrant left AFL (n = 9), focal left AT (n = 3), typical right AFL (n = 6), and atypical right AFL (n = 1). Of the 19 completely characterized atrial arrhythmias, catheter ablation was performed for 18, and the procedure was successful for 13 of these. After a mean follow-up of 15 +/- 10 months, 15 of 20 patients (75%) were in sinus rhythm including 10 of 13 patients (77%) with AT/flutter ablation. Ten patients, including 6 following ablation, were maintaining sinus rhythm without antiarrhythmic medications. CONCLUSIONS: Patients with an ECG diagnosis of AFL or AT following surgical atrial fibrillation ablation may have multiple tachycardia mechanisms with the right or left atrium as the site of origin. Many of these rhythms may resolve with further maturation of surgical atrial fibrillation ablation (SAFA) lesions or be treatable with antiarrhythmic medication. However, persistent tachyarrhythmias can often be treated successfully with catheter mapping and ablation.