Catheter ablation for cardiac arrhythmias

With the introduction of radiofrequency energy, catheter ablation has become an established technique for managing many cardiac rhythm disturbances. High efficacy and safety have been reported for accessory pathway ablation, selective fast and slow atrioventricular nodal pathway ablation to eliminate atrioventricular nodal reentrant tachycardia (while preserving atrioventricular conduction), atrioventricular junctional ablation to control the ventricular response to atrial tachyarrhythmias, ablation of the right bundle branch to eliminate bundle branch reentrant ventricular tachycardia, and ablation of the site of tachycardia origin in patients with ventricular tachycardia unassociated with structural heart disease. In addition, there has been active investigation into ablation techniques for more complex arrhythmias such as atrial tachycardia, atrial flutter, and ventricular tachycardia associated with structural heart disease.     

Right atrial thrombus formation after transvenous catheter ablation of the atrioventricular node

The formation of a right atrial mass was detected in a patient by two-dimensional echocardiography 3 weeks after successful transvenous electrical ablation of the atrioventricular node had been performed. The mass was attached to the atrial septum at the site where the electrode catheter used for the ablation had supposedly been located and it exhibited no mobility. It was interpreted as a right atrial thrombus induced by the ablation procedure. Although no pulmonary embolic events have been observed during a 7 month follow-up period, right atrial thromboembolism must be considered a potentially dangerous complication of transvenous catheter ablation to control cardiac arrhythmias.     

三维标测系统指导下复杂心律失常的经导管射频消融治疗

目的:探讨在三维标测系统指导下,经导管复杂心律失常射频消融治疗的有效性与安全性. 方法:选择2006年2月至2008年9月住院患者98例,其中阵发性房颤50例、持续性或永久性房颤6例、心房扑动9例、房性心动过速(房速)9例、室性心动过速(室速)或频发室性早搏24例.在EnSite NavX或Array系统(72例)或CARTO系统(26例)指导下进行射频消融手术. 结果:84例一次手术成功(85.71%),7例再次导管消融成功,成功率合计92.86%.50例房颤一次手术成功,5例再次消融后3例成功.9例心房扑动患者中7例一次手术成功,1例复发再次消融成功.9例房速中7例一次手术成功,1例复发再次消融成功.24例室速、室早患者中20例一次消融成功,4例行再次消融2例成功.共有并发症6例:心包填塞4例,左前降支远端栓塞1例、术后肺栓塞1例. 结论:三维标测系统可清晰地显示心脏三维立体结构,对复杂疑难心律失常的射频消融治疗具有较好的指导作用,提高消融的成功率并增加手术安全性.     

网篮电极导管临床使用的初步经验

目的：评价64极网篮电极导管在电生理检查及射频消融中的实用价值。方法：4例患者,根据发作时心电图诊断为房性心动过速（房速）3例,左心室室性心动过速1例,网篮电极导管分别经右侧股静脉或股动脉送入右心房或左心室,选择记录双极心电信号,对每1例患者均进行窦性心律及心动过速时的标测,并在网篮电极导管指引下进行消融,结果：4例患者网篮电极导管均顺利送入,术中及术后无明显并发症发生,通过网篮电极所记录心电信号清晰,稳定,根据计算机所绘制等时标测图及网篮在心腔内的影像位置,可准确地判断除极波传播顺序,方向及最早激动点,确定心律失常的起源部位及发生机制,2例房速及1例室性心动过速患者消融成功,另1例房速患者消融失败。结论：利用网篮电极导管进行心内膜高密度标测,有助于提高心脏电生理检查及射频消融手术的效率。     

三维标测系统指导下复杂心律失常的经导管射频消融治疗

目的：探讨在三维标测系统指导下,经导管复杂心律失常射频消融治疗的有效性与安全性。方法：选择2006年2月至2008年9月住院患者98例,其中阵发性房颤50例、持续性或永久性房颤6例、心房扑动9例、房性心动过速（房速）9例、室性心动过速（室速）或频发室性早搏24例。在EnSite NavX或Array系统（72例）或CARTO系统（26例）指导下进行射频消融手术。结果：84例一次手术成功（85．71％）,7例再次导管消融成功,成功率合计92．86％。50例房颤一次手术成功,5例再次消融后3例成功。9例心房扑动患者中7例一次手术成功,1例复发再次消融成功。9例房速中7例一次手术成功,1例复发再次消融成功。24例室速、室早患者中20例一次消融成功,4例行再次消融2例成功。共有并发症6例：心包填塞4例,左前降支远端栓塞1例、术后肺栓塞1例。结论：三维标测系统可清晰地显示心脏三维立体结构,对复杂疑难心律失常的射频消融治疗具有较好的指导作用,提高消融的成功率并增加手术安全性。     

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。     

Robotic Catheter Ablation of Ventricular Tachycardia in a Patient with Congenital Heart Disease and Rastelli Repair

Robotically assisted catheter ablation has been proven feasible in patients with a variety of atrial arrhythmias. The potential to provide improved catheter tip maneuvering and stability potentially makes it ideal for complex ablation procedures. We present the case of a patient with complex congenital heart disease with previous Rastelli repair and recurrent ventricular tachycardia (VT) who underwent robotically assisted mapping and ablation for right ventricular VT, utilizing substrate mapping techniques.     

Radiofrequency catheter ablation of various kinds of arrhythmias guided by virtual electrograms using a noncontact, computerized mapping system.

Three-dimensional visualization of cardiac activation has become important for providing further insights into the pathophysiological mechanisms of arrhythmias and to increase the efficacy of catheter ablation. The noncontact mapping system enables a single-beat analysis of the reconstructed geometry of the cardiac chamber. In 8 patients with various kinds of arrhythmias (3 with atrial flutter, 2 with right ventricular outflow tract ventricular tachycardia, 1 with idiopathic left ventricular tachycardia, 1 with atrioventricular nodal reentrant tachycardia and 1 with concealed Wolff-Perkinson-White syndrome), non-contact mapping using an EnSite 3000 system was performed for the guidance of catheter ablation. The optimal sites for successful ablation were detected and all of these arrhythmias were successfully eliminated with the radiofrequency energy applications without any adverse effects. The computerized EnSite 3000 mapping system described here computes accurate isopotential maps that are a useful guide for catheter ablation.     

Electrical ablation of atrial muscle. I. Early and late anatomic observations in canine atria

Electrode catheter ablation (ECA) of atrial muscle may be a useful technique for the treatment of drug-refractory supraventricular tachycardias originating in the right atrial free wall (RAFW). We performed this study in order to determine: (1) the safety of electrical shocks applied to the RAFW and (2) the early and late anatomic effects of ECA. Twelve beagle puppies, ranging in age from 2.0 to 7.5 months and weighting 2.3 to 8.0 kg, underwent electrical ablation of the RAFW, using energy doses of 100 to 400 J. At the highest energy doses tested (400 J), one puppy died of refractory ventricular fibrillation and one of low cardiac output. Atrial perforation and cardiac tamponade occurred in two puppies, each of which received one shock of 200 J. The area of myocardial damage following ECA shocks of 150 J was greater than for shocks of 100 J, 94 +/- 14 vs 56 +/- 11 mm2, respectively (p less than 0.02). Acutely, ECA produced transmural hemorrhagic necrosis. Eleven weeks after electrical ablation, atrial fibrosis was apparent at the site of ablation. In conclusion, ECA may be used to fulgurate atrial tissue in the RAFW. We recommend 150 J as a safe upper limit in small subjects, although higher energy doses may not produce cardiac perforation or adverse hemodynamic effects in larger subjects.     

CARTO系统指导射频消融的应用评价

目的对比研究CARTO标测系统在指导消融术中的弊与利.方法 6例病人同时接受CARTO及普通心内电信号标测双系统指导下的射频消融.其中左房局灶性房速3例、右房房速1例、左室非典型部位特发性室速1例、先心矫形及修补术后室速1例.除1例房速外,均为接受第二或第三次手术的病人,普通心内电信号标测同常规,CARTO电解剖标测系统利用电磁原理首先建立感兴趣区的三维空间,然后诱发心动过速,心动过速时标测折返环,窦性心律下或心动过速时进行消融.结果 6例病人成功4例.未成功的两例病人为因心包填塞中止手术的患者,其中1例为左房局灶性房速、1例左室非典型部位特发性室速,心包穿刺后缓解,无1例死亡.结论 CARTO电解剖标测系统的优点在于可以术中描绘出心动过速的折返环路、无须太多的X线曝光量、提高复杂心律失常射频消融的成功率,节省手术时间.但对于简单心律失常来讲,建立感兴趣区的三维结构,要耗用不必要的标测时间,使简单问题复杂化,此外费用较高.由于CARTO系统无法观察到整个导管的走性情况,导管在心腔内的张力无法判断,因此容易出现心包填塞等并发症.因此CARTO电解剖标测系统的主要优势在于器质性心脏病引起的复杂心律失常的射频消融.     

Catheter ablation of a monofocal premature ventricular complex triggering idiopathic ventricular fibrillation

A 62 year old man was admitted for evaluation of recurrent episodes of syncope. A surface ECG showed frequent repetitive premature ventricular complexes of right ventricular outflow tract origin. Ventricular fibrillation was inducible by programmed electrical stimulation but otherwise cardiac evaluation was unremarkable. A diagnosis of idiopathic ventricular fibrillation was made and an implantable cardioverter-defibrillator (ICD) was installed. However, spontaneous ventricular fibrillation recurred, requiring repeated ICD discharges. The ventricular fibrillation was reproducibly triggered by a single premature ventricular complex with a specific QRS morphology. Radiofrequency catheter ablation was carried out to eradicate this complex. No ventricular fibrillation has developed after this procedure, and the patient does not require drug treatment.


Keywords: ventricular fibrillation; radiofrequency ablation     

Intracardiac echocardiography in electrophysiology

Intracardiac echocardiography (ICE) broadens the spectrum of echocardiographic techniques. Modern 10F sector echocardiographic catheters introduced into the right atrium allow high quality imaging of all cardiac structures, including pulse and continuous wave Doppler and/or color Doppler. The main indication for ICE appears to be monitoring of catheter ablation of complex arrhythmic substrates such atrial fibrillation, postincisional tachycardias and ventricular tachycardias. The other important role of ICE is the early diagnosis and prevention of complications during ablation procedures. These include those occurring during transseptal catheterization, damage to cardiac structures, left atrial thrombus formation, pulmonary venous stenosis, esophageal injury and pericardial effusion.     

Catheter ablation after the direct electrical recording of the bundle of Kent. Apropos of 3 cases

The success rate of catheter ablation, the latest therapeutic method in the treatment of cardiac arrhythmias, varies according to the precise indication. The best and most logical guarantee of its efficacy is the application of the electrical energy at an anatomical site essential to the arrhythmia. In preexcitation syndromes this site is without doubt the accessory pathway itself rather than its insertions, but this implies the recording of its activation. We recorded the electrical activation of a right sided Kent bundle in three consecutive cases to guide the therapeutic procedure (comparable to the recording of the H potential for his bundle ablation). All patients had paroxysmal atrial fibrillation (minimal RR interval: 175, 150 and 200 ms) and orthodromic reciprocating tachycardia. Two patients had had attacks of ventricular fibrillation. The sites of the Kent bundles were posteroseptal in 2 cases and anterolateral in 1 case. The recording of the electrical activation of the Kent bundle was validated by: the passage (induced or spontaneous) of a preexcited to a normal QRS coincident with the disappearance of the K potential; the exclusion of an atrial or ventricular origin of the electrical activation supposed to be the activation of the Kent bundle; electrical stimulation at the site of the recording of the K potential leading to prolongation of the stimulus-delta wave interval from 10 to 35 ms, with QRS morphology identical to the spontaneous complexes. All 3 patients were clinically cured by catheter ablation at the site of recording of the Kent bundle activation with follow-up periods ranging from 10 to 16 months.(ABSTRACT TRUNCATED AT 250 WORDS)     

阵发性心房颤动节段性肺静脉电隔离方法学评价

目的评价经改良的节段性电隔离肺静脉方法治疗阵发性心房颤动的有效性及安全性.方法 39例阵发心房颤动患者,男性28例,女性11例,采用一次房间隔穿刺技术,送入标测及消融电极,并选用猪尾造影导管用高压非选择性造影显示肺静脉开口及左心耳位置,指导导管行进方向以减少心脏压塞风险.标测中常规探查、标测右下肺静脉,避免遗漏可能触发心房颤动的肺静脉电位.在肺静脉电位优势传导部位消融并轻微移动形成节段性电隔离.结果单个节段或多个节段消融可使肺静脉与左心房之间形成完全性电隔离.节段性隔离靶肺静脉85根,即刻成功81根,成功率95%,无并发症发生.结论节段性电隔离肺静脉法可有效隔离肺静脉,与其他传统方法比较,手术时间短、成功率高,可减少肺静脉的损伤和避免肺静脉狭窄的发生.     

AV nodal ablation-induced Gerbode defect (LV-RA Shunt)

A Gerbode defect that comprises a left ventricular to right atrial shunt is usually a congenital cardiac condition. Rarely, acquired Gerbode defects secondary to aortic or tricuspid valve endocarditis have been reported. We present a case of a Gerbode defect caused by catheter ablation of the AV node in a patient with a severely dilated cardiomyopathy and refractory atrial fibrillation.     

Catheter ablation for cardiac arrhythmias

The clinical introduction of catheter ablation in 1981 revolutionized the treatment of cardiac arrhythmias. Implementation of radiofrequency as an alternative energy source, with the advantages of higher selectivity and less collateral damage, provided an expansion of catheter ablation therapy. Today the majority of arrhythmias can potentially be cured with catheter ablation therapy. The safety and efficacy of catheter ablation for treatment of AV nodal reentrant tachycardia, accessory pathway arrhythmias, focal atrial tachycardia, atrial flutter and idiopathic ventricular tachycardia, is well established. Catheter ablation for treatment of atrial fibrillation and ventricular tachycardia secondary to structural heart disease, remains an area of active research. In this article we will review the current state of knowledge about the technique, indications, and results of catheter ablation for the treatment of cardiac arrhythmias.     

Right atrial thrombus formation following transvenous catheter ablation of the AV conduction system

A case is reported in which the formation of a right atrial mass was detected by two-dimensional echocardiography 3 weeks after successful transvenous electrical ablation of the atrioventricular junction had been performed. The mass was attached to the atrial septum at the site where the electrode catheter used for the ablation had been located and it exhibited no mobility. It was interpreted as a right atrial thrombus induced by the ablation procedure. Although no pulmonary embolic events have been observed during a 7-month follow-up period, right atrial thrombus formation must be considered as a potentially dangerous complication of transvenous catheter ablation to control supraventricular arrhythmias.     

Real-Time Cardiac Catheter Navigation on Three-Dimensional CT Images

Introduction: Targets for ablation of atrial fibrillation, atrial flutter, and non-idiopathic ventricular tachycardia are increasingly being selected based on anatomic considerations. Because fluoroscopy provides only limited information about the relationship between catheter positions and cardiac structures, and is associated with radiation risk, other approaches to mapping may be beneficial. Methods: The spatial and temporal information of an electromagnetic catheter tip position sensing system (Magellan, Biosense Inc.) was superimposed on a three-dimensional (3D) CT of the chest in swine using fiducial markers for image registration. Position and orientation of a 6 French catheter with an electromagnetic sensor was displayed in real-time on a corresponding 3D-CT. Catheter navigation within the heart and the great vessels was guided by detailed knowledge about catheter location in relation to cardiac anatomy. Results: Anatomic structures including the atrial septum, pulmonary veins, and valvular apparatus were easily identified and used to direct catheter navigation. During the right heart examination, the catheter was navigated through the superior and inferior vena cava to predetermined anatomic locations in right atrium, right ventricle and pulmonary artery. The ablation catheter was also navigated successfully from the aorta through the aortic valve in the left ventricle. No complication was encountered during the experiments. The accuracy and precision of this novel approach to mapping was 4.69 ± 1.70 mm and 2.22 ± 0.69 mm, respectively. Conclusions: Real-time display of catheter position and orientation on 3D-CT scans allows accurate and precise catheter navigation in the heart. The detailed anatomic information may improve anatomically based procedures like pulmonary vein ablation and has the potential to decrease radiation times.     

阵发性心房颤动患者上腔静脉肌袖与心房的电学连接特征

总结 16例阵发性心房颤动患者上腔静脉 (SVC)肌袖的电生理标测和导管射频消融电隔离的结果 ,评价SVC肌袖和心房电连接的类型和特点。在环状标测电极指导下 ,对 16根SVC肌袖进行电位的记录、分析以及开口部的点或段的消融电隔离治疗。根据窦性心律和心房起搏下的肌袖内环形电极标测的袖电位激动顺序 ,即电突破点的数目和位置 ,以及有效放电对袖电位及其电突破点的影响 ,总结和分析袖房之间的电连接类型和特点。结果 :共标测和电隔离SVC肌袖 16根。其中呈单束状电连接 8根 (5 0 % ) ,双束状电连接 7根 (43.7% ) ,多束状电连接 1根 (6 .3% )。 16根SVC平均每根电连接束为 1.6± 0 .6根 ,共消融 2 .1± 0 .6个节段和部位 ,每个部位进行了2 .3± 0 .7次的放电。所有病例均达到完全电隔离的标准。结论 :SVC袖房之间电连接的类型多为单束状和双束状 ,在袖房连接处行点或节段性消融即可达到完全袖房电隔离的结果。