左室流出道室性心律失常的射频消融治疗

目的 探讨起源于左室流出道少见部位的室性心动过速和/或频发室性早搏的心电图特点和射频消融治疗.方法 3例左室流出道室速和/或室早患者,术中进行激动和起搏标测,同时结合冠状动脉造影或三维电解剖标测系统(CARTO)定位.结果 3例患者中2例体表心电图特点类似右室流出道间隔部室速及室早,经腔内电生理证实起源于主动脉根部右冠窦内.1例起源于主动脉瓣-二尖瓣连接区(AMC),该部位室速及室早特有的典型心电图表现为II、III、aVF及所有胸前导联QRS波均呈R形.3例患者消融后观察2~24个月,均无复发.结论 右冠窦和AMC是左室流出道室速和/或室早的少见特殊起源部位,根据体表心电图形态,结合多种腔内标测技术及冠脉造影,能进行准确定位及成功消融.     

射频导管消融治疗频发右心室室性期前收缩伴缓慢心率及随访

目的 探讨应用射频导管消融治疗频发右心室室性期前收缩伴缓慢基础心率的可行性。方法 53例症状明显、发作频繁、药物疗效不佳或不能耐受的频发右心室室性期前收缩患者，按射频导管消融治疗室性心动过速的手术流程，用起搏标测法结合激动标测消融室性期前收缩，以消融后期前收缩消失且静脉滴注异丙肾上腺素期前收缩不再出现为手术终点；以术后24h及30d复查动态心电图无同一形态室性期前收缩为成功标志；期前收缩显著减少且症状明显减轻作为显效标准。结果 50例患者成功消融室性期前收缩，术后症状消失，复查Holter未见同形室性期前收缩，随访3～31个月无复发及新的室性期前收缩出现；2例术后24h分别残余27次及132次同形室性期前收缩，但随访期间患者均无症状；失败1例。结论 对于症状明显、药物疗效不佳的频发性右心室室性期前收缩伴缓慢基础心率患者射频导管消融治疗可取得满意的疗效。     

特发性室性心动过速的射频消融治疗

目的评价室性心动过速经导管射频消融治疗的有效性和安全性。方法对12例正常心脏室速进行导管消融，采用起搏标测与激动顺序标测，前者以起搏时与室速QRS波型形态完全相同，后者以激动顺序标测法定位，以记录心动过速时较体表心电图QRS提前≥20ms的最早高频低振幅局部电位处为消融靶点，结果12例患者室速起源部位分别为：右心室2例，左心室10例，疗效100％。所有病人无任何并发症。结论对于发作频繁、症状明显的IVT，射频消融是一种安全、可靠、成功率高的根治方法。     

经导管射频消融治疗右室流出道室性期前收缩

目的　评价经导管射频消融治疗单形性右室流出道室性期前收缩的有效性和安全性。方法　采用射频导管消融术对 4 2例症状严重的正常心脏单形性右室流出道室性期前收缩进行治疗 ,男 2 8例 ,女 14例 ,年龄 (42 .2±7.8)岁。将消融电极送至右室流出道区域 ,采用起搏标测和激动顺序标测 ,前者以起搏时与室性期前收缩QRS波形态完全相同为消融靶点 ,后者以室性期前收缩时最早心室激动点为消融靶点。 4 2例室性期前收缩全部起源于右室流出道 ,呈左束支阻滞图形 ,其中 36例起源于右室流出道间隔部 ,6例起源于右室流出道游离壁。以室性期前收缩在放电后 10秒内消失 ,并维持窦性心律 30～ 6 0min为即刻成功标准。结果　消融即刻成功率为 90 .5 % (38/ 4 2 ) ,其中右室流出道间隔部 94 .4 % (34/ 36 ) ,游离壁 6 6 .7% (4/ 6 )。 2 0例患者 2 4小时动态心电图记录消融前后室性期前收缩数分别为 (2 0 80 0± 10 4 0 )次 / 2 4h和 (110± 12 0 )次 / 2 4h(P <0 .0 0 1)。 1例患者消融术中出现室颤经电复律恢复窦性心律 ,其余无任何并发症。随访 4～ 16个月症状缓解率为 89.5 % (34/ 38) ,复发率为 5 .3% (2 / 38) ,均为右室流出道游离壁室性期前收缩。随访期间亦无并发症。结论　经导管射频消融可有效地治疗症状重、药     

三维标测系统指导下希氏束旁室性期前收缩的射频消融

目的 探讨三维标测系统指导下右心室流入道间隔部希氏束附近起源室性期前收缩射频消融效果.方法 无器质性心脏病心电图提示频发性间隔部希氏束附近室性期前收缩患者5例,分别在室性期前收缩时进行三维重建右心室和主动脉窦,标识希氏束及放电部位,消融时实时观察导管位置方向.结果 5例患者分别于前间隔(2例)、中间隔(1例)、后间隔(2例)标测到消融靶点,放电后前间隔部、后间隔部患者室性期前收缩均消失,中间隔患者消融失败.无房室传导阻滞并发症.随访3～10个月,成功病例未应用抗心律失常药物,无室性期前收缩发作.结论 三维标测系统指导右心室流入道间隔部希氏束附近起源室性期前收缩消融安全、有效.     

导管射频消融治疗特发性室性心动过速临床分析

目的:探讨导管射频消融治疗特发性室性心动过速(idiopathic ventricular tachycardia,IVT)的效果.方法:对34例IVT患者进行射频消融治疗,起源于左室特发性室性心动过速(LIVT)采用激动标测法或起搏标测最早QRS波相结合;对右室特发性室性心动过速(RIVT)采用起搏标测法标测靶点,标测靶点后放电消融.结果:34例行心内电生理检查时均诱发出室性心动过速,其中30例消融成功,临床症状消失,无手术相关并发症;4例失败,随访期间复发,再次消融成功.结论:导管射频消融术能够根治IVT,成功率高,且安全可行,可作为治疗IVT的首选方法.     

导管射频消融治疗特发性室性心动过速的临床效果

目的评价射频消融治疗特发性室性心动过速的临床效果。方法收集2003年8月～2005年8月在我院进行射频消融治疗的特发性室性心动过速（IVT）患者29例，缘于右心室IVT采用消融导管起搏标测法，以起搏时与VT发作时12导联QRS波形态与振幅完全相同的起搏部位为消融靶点，并在周围做巩固消融；起源于左心室IVT采用激动顺序标测法或寻找P电位。结果27例即刻成功，2例失败，成功率93．1％，随访1年3例复发，再次手术后成功。结论射频消融治疗特发性室性心动过速疗效肯定，成功率高，复发率低。     

右心室流出道单形态室性心律失常的射频消融治疗观察

目的对起源于右心室流出道(RVOT)单形态室性心律失常消融结果进行分析并探讨应用Carto系统对射频消融(RFCA)的指导作用。方法对185例RVOT起源的单形态室性心律失常(VT/PVCs)患者行RFCA治疗,患者年龄4～84岁,平均年龄(40.5±12.3)岁,病史3～22年,平均病史7.2年。这些患者临床症状明显,服用抗心律失常药物不能控制,临床检查未发现有心脏结构的异常改变。所有患者的临床心电图呈现左束支阻滞,其中Ⅱ、Ⅲ、aVF导联呈高R波,术前动态心电图提示患者的室性早搏数量为5342～52460/24h,伴或不伴室速。应用激动+起搏标测成功判定消融部位。18例患者尝试应用Carto标测系统进行治疗。结果所有病例中149例RVOT偏间隔部,36例偏游离壁。绝大多数病例通过激动标测最早心室激动时间(EVA)距离体表QRS时间(EVA-QRS)为(32.6±9.4)ms,同时结合起搏标测成功进行消融。在4例复发病例中8mm头端消融导管或盐水灌注消融导管较4mm头端消融导管更具优势。在2个月至8年的随访中,4例(2.1%)复发,在重新手术后获得成功。应用Carto系统标测的患者均取得了良好的治疗效果。结论在传统的激动+起搏标测下,RVOT起源单形态VT/PVBs的RFCA治疗有较高的成功率和低复发率。Carto系统的应用进一步提高了手术的成功率。     

射频消融治疗特发性室性心动过速的临床观察

目的观察射频消融(RFCA)治疗9例特发性室性心动过速(IVT)方法和结果。方法分别行激动顺序标测法和起搏标测法,对左室特发性室速(ILVT)7例,右室特发性室速2例,行射频消融治疗。结果6例ILVT射频消融治疗成功,均起源于左室间隔面,有效消融靶点处P电位较体表心电图QRS起始点提前(34.6±8.9)m s(25~58 m s),2例IRVT射频消融成功,有效消融靶点处与心动过速时的12导联心电图QRS波形完全相同。无一例出现并发症。结论射频消融是治疗特发性室性心动过速的有效方法。     

特发性室性心动过速射频导管消融方法探讨

目的：探讨特发性室性心动过速（IVT）的消融方法。方法：对12例IVT患者进行射频消融治疗，源于右心室IVT采用消融导管起搏标测法，以起搏时与VT发作时的12导联心电图QRS波形态与振幅完全相同的起搏部位为消融靶点。并在周围做巩固消融，起源于左心室IVT以激动标测法或寻找P电位。结果：IVT消融成功率91．6％（11／12），1例ILVT在第3次复发射频消融后发生双束支阻滞而安装了VVI永久起搏器。结论：起源于左心室的IVT宜采用激动顺序标测法，起源于右心室的IVT宜采用起搏标测法。对有效靶点周围进行线状或环状消融，有利于提高手术成功率。     

左侧房室旁道射频消融中特殊心电现象与处理对策

目的报道24例左侧房室旁道射频消融的特殊心电现象与处理对策。方法1例左后侧壁显性房室旁道经心内膜标测和消融不成功,改冠状静脉窦标测和消融,术中冠状静脉窦造影了解其结构。2例射频消融后旁道呈间歇性逆传,采用心室RS2刺激法进行标测与消融。6例冠状窦电极显示激动的先后顺序不明显,其中1例消融导管在二尖瓣环心室侧和心房侧均未标测到满意靶点图,多次试放电失败,最终在左中间隔消融;另5例消融导管在明显高于冠状窦电极的部位才标侧到满意靶图。10例消融导管在二尖瓣环心室侧始终未标测到满意靶点图,或反复消融仅能一过性阻断旁道,改动脉途径逆行法心房侧消融。7例心室起搏下消融不成功而采用窦性心律下放电。结果全部病例消融成功。结论极少数左侧房室旁道由于其特殊的电生理现象往往需采用不同的标测和消融策略。     

前间隔心动过速源于主动脉无冠窦的射频消融

【目的]探讨经主动脉无冠窦途径导管射频消融治愈的前间隔房速、前间隔旁路患者的心电图特点及射频消融治疗情况。【方法】回顾性分析经无冠窦途径导管射频消融治愈的3例前间隔房速和2例前间隔旁路的体表心电图、心内电图以及消融成功时靶点电图等心电生理学特征。【结果】3例局灶性前间隔房速均能被心房刺激反复诱发和终止,其心电图特点：房速时P波间期明显窄于窦律时P波间期,I、aVL导联P渡正向,Ⅱ、Ⅲ和aVF导联P呈负正双向,心房标测提示最早的心房激动在希氏柬区,但主动脉无冠窦内标测的心房激动较希氏束区的心房波提前,解剖定位希氏柬上后方,消融靶点无希氏束电位。2例前间隔旁路心电图示：窦性心律时呈窄ORS波形,未见预激波,心动过速呈窄QRS形,在主动脉无冠窦内记录到最早心房激动点,且无希氏柬电位。5例均在无冠窦消融成功。随访15．2±12．1（2～40）个月,无复发病例。【结论】源于无冠窦的前间隔房速和前间隔旁路具有其相对的心电生理学特征,常规心内膜途径消融困难时应考虑从无冠窭玲径标测消融策略．     

Hybrid Therapies for Ventricular Arrhythmias

In recent years several trials demonstrated the efficacy of implantable cardioverter-defibrillation (ICD) therapy in reducing cardiac and total mortality in patients affected by rapid ventricular tachycardia (VT) and/or ventricular fibrillation. Nevertheless, ICD do not prevent arrhythmia recurrences, thus being a palliative and not a curative treatment modality. The tolerance to ICD therapy varies greatly, and within individuals, this leading to a nonuniform acceptance of this form of therapy. The very frequent occurrence of VT, defined as an arrhythmic storm, may be a life threatening condition. The majority of ICD patients is under antiarrhythmic drug therapy, to reduce episodes of VT or to make antitachycardia pacing more effective by slowing the tachycardia rate. Drug therapy, however, may cause additional problems, and does not represent the optimal solution. The prevention of VT and/or ventricular fibrillation episodes and excessive ICD therapy, remains a worthwhile goal. Radiofrequency catheter ablation (RFCA) is a curative approach, and can be expected to reduce the frequency of recurrent VT episodes in the majority of patients. The combination of these treatment modalities (ICD and RFCA) is often described as hybrid therapy, implying that the two treatments act providing some form of synergism. In experienced centers, RFCA is now performed, regardless of whether the VT rate is rapid and/or is hemodynamically unstable. Newer mapping and ablation techniques are now available, enhancing the acute success rate of the procedure. In this review the most recent application of VT catheter ablation and the use of advanced mapping and ablation techniques will be discussed.     

Recurrence of RVOT PVCs with a Marked Shift of Its Exit Point. Gradual Elimination of Arrhythmogenic Focus by Multisite Approach

We present a case of recurrent outflow tract arrhythmia despite repeated ablations. Premature ventricular contractions (PVCs) morphology suggested a right‐sided focus. However, electrograms preceding PVCs were recorded from the right and left outflow tracts, distal coronary sinus, and right sinus of Valsalva. Arrhythmia was eliminated after radiofrequency (RF) applications delivered from different sites. We conclude that, in patients with recurrent outflow tract PVCs, mapping all the sites mentioned above may be necessary to find the earliest activation site and carry out successful ablation. In some patients, RF applications from multiple sites may be necessary to completely eliminate arrhythmia. (PACE 2012; 35:e6–e9)     

Ablation of nonsustained or hemodynamically unstable ventricular arrhythmia originating from the right ventricular outflow tract guided by noncontact mapping

Conventional activation or pacemapping is effective in guiding ablation of ventricular tachyarrhythmia originating from right ventricular outflow tract (RVOT). However, in selected patients with hemodynamically unstable or nonsustained tachycardia, noncontact mapping may be an effective alternative method to guide ablation in RVOT. Five patients with symptomatic hypotension during ventricular tachycardia (VT) or nonsustained tachyarrhythmia originating from the RVOT had radiofrequency ablation guided by noncontact mapping. All patients had a history of syncope and the tachyarrhythmias were refractory to antiarrhythmic therapy. Four patients had spontaneous sustained VT of a cycle length from 250 to 300 ms and one had symptomatic ventricular ectopic beats. Two patients were diagnosed to have arrhythmogenic right ventricular cardiomyopathy (ARVC). Sustained VT with hypotension was induced in two patients and nonsustained VT in three patients. Isopotential color maps were used to locate the earliest activation site of the tachyarrhythmia in RVOT. Three patients had tachyarrhythmia exit sites at the septal region and two at lateral region of RVOT. Low voltage area and diastolic activity were detected in the two patients with ARVC. Radiofrequency ablation guided by noncontact mapping was performed during sinus rhythm in all patients. The number of ablation attempts ranged from 1 to 14. After follow-up for 12 +/- 5.8 months, there was no recurrence of tachyarrhythmia and syncope in all five patients. Noncontact mapping is a safe and effective alternative method to guide ablation of hemodynamically unstable or nonsustained ventricular arrhythmia originating from RVOT.     

Characterization of the electroanatomic substrate for monomorphic ventricular tachycardia in patients with nonischemic cardiomyopathy

Ventricular arrhythmias are common in the setting of nonischemic cardiomyopathy. The etiology for the cardiomyopathy is frequently not identified and the label of "idiopathic" is applied. Interstitial fibrosis with conduction system involvement and associated left bundle branch block characterizes the disease process in some patients and the mechanism for monomorphic ventricular tachycardia is commonly bundle branch reentry. However, most patients with nonischemic cardiomyopathy have VT due to myocardial reentry and demonstrate marked myocardial fibrosis and electrogram abnormalities. Although patient specific, the overall distribution of electroanatomic abnormalities appears to be equal on the endocardium and epicardium. The extent of electrogram abnormalities appears to parallel arrhythmia presentation and/or inducibility. Patients with sustained uniform morphology VT have the most extensive endocardial and epicardial electrogram abnormalities. Magnetic electroanatomic voltage mapping provides a powerful tool to characterize the location and extent of the arrhythmia substrate. Basal left ventricular myocardial involvement, as indexed by the location of contiguous electrogram abnormalities, is common in patients with sustained VT and left ventricular cardiomyopathy. The relatively equal distribution of electrogram abnormalities on the endocardium and epicardium, and the results of mapping and ablation attempts, suggest that critical parts of the reentrant circuit may be epicardial. Unique features of the electroanatomic substrate associated with cardiomyopathy due to Chagas' disease, sarcoidosis, and arrhythmogenic right ventricular dysplasia are also discussed.     

Radiofrequency catheter ablation from the left sinus of Valsalva in a patient with idiopathic ventricular tachycardia

We report the case of a 54-year-old woman with idiopathic VT originating in the left ventricular outflow tract. She initially presented with palpitations and light-headedness. The morphology of the PVCs exhibited an inferior axis and tall R waves were noted in all the precordial leads. Spontaneous PVCs were transiently terminated by an intravenous injection of adenosine triphosphate. Radiofrequency catheter ablation from the left sinus of Valsalva successfully abolished the PVCs and the VT.     

Aortic root dissection with left valsalva sinus perforation detected by transesophageal 3D echocardiography in a patient with Behçet's disease

Behçet's disease (BD) is a multi‐system inflammatory disorder. We report the case of a BD patient with severe aortic root vasculitis. Two‐dimensional transthoracic echocardiography (2DE) images suggested left Valsalva sinus aneurysm ruptured into the left ventricular outflow tract. However, preoperative transesophageal real‐time 3‐dimensional echocardiography (3DE) revealed that the aneurysm‐like structure involved most of the left ventricular outflow tract wall, leading to the diagnosis of aortic root dissection associated with perforation of the left Valsalva sinus and prolapse of the exfoliated endocardium into the left ventricular outflow tract. These findings were confirmed by open heart surgery. 3DE was helpful differentiating aortic root dissection from Valsalva sinus aneurysm rupture, especially by demonstrating the extent of aneurysm‐like structure in the left ventricular outflow tract. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound 42 :59–62, 2014     

Automated Template Matching to Pinpoint the Origin of Right Ventricular Outflow Tract Tachycardia

Background: Template matching, a technique that examines the similarity between two QRS complexes, has not been broadly applied clinically.
Methods: The 16 patients enrolled in this study underwent radiofrequency catheter ablation (RFCA) at the site of five ventricular tachycardias (VT) and of premature ventricular contractions (PVC) arising from 25 sites in the right ventricular outflow tract (RVOT), under the guidance of conventional pace and activation mapping. After RFCA, (a) a template-matching score using a correlation coefficient, and (b) a pace-map score were calculated at 30 successful and 48 unsuccessful ablation sites.
Results: The template-matching score at successful ablation sites (94 ± 4%) was significantly higher than at unsuccessful (85 ± 9%) ablation sites (P < 0.001). A ≥ 90% average matching score identified successful ablation sites with a sensitivity of 90% and specificity of 69%. While there was a significant correlation between the template-matching score and visually judged pace-map score (r = 0.63, P < 0.0001), the area under the receiver operating characteristic curve of the template matching score was larger than that of the pace-map score (0.80 vs. 0.67).
Conclusions: Automated template matching was useful for localizing the optimal ablation site during RFCA of RVOT-VT/PVC.