射频导管消融特发性左心室流出道室性心动过速

目的 探讨特发性左心室流出道室性心动过速(室速)心电图特点及射频导管消融结果。方法 对5例未发现器质性心脏病的左心室流出道室速患者行12导联心电图、动态心电图、心内电生理检查及射频导管消融治疗。结果5例患者心电图Ⅱ、Ⅲ、aVF导联呈R波；Ⅰ导联呈rs或QS波，振幅大于0．5mV；V1导联呈rs或RS波，胸前导联R波移行发生于V2～V3；aVR和aVL导联呈QS波，3例患者的消融靶点在左冠状窦口内，2例位于主动脉瓣下，随访6个月，无1例复发。结论 左心室流出道室速有特殊心电图表现，射频导管消融是首选的治疗措施。     

Successful catheter ablation of focal atrial tachycardia from the non-coronary aortic cusp.

We describe a patient with frequent episodes of unusual paroxysmal supraventricular tachycardia. During the electrophysiological examination, the tachycardia was easily induced and terminated by atrial pacing. The earliest activation during right atrial activation mapping was located near the atrioventricular node and the His bundle. However, detailed mapping of the aortic root demonstrated that the local activation in the non-coronary aortic cusp preceded the activation at the His bundle region. Radiofrequency catheter ablation at this site terminated the tachycardia with no complications.     

右室流出道起源与主动脉窦起源室性早搏的分析

目的 探讨右室流出道起源与主动脉窦起源室性早搏心电图的主要区别.方法 回顾分析因频发室性早搏,心电图室性早搏胸前导联呈左束支传导阻滞,Ⅱ、Ⅲ、aVF导联QRS主波向上,行射频消融成功的患者126例,分为右室流出道（RVOT）起源组66例,主动脉窦（ASC）起源组60例.结果 V1、V2导联R波时限指数和R/S波幅指数ASC组高于RVOT组.胸前导联移行区指数RVOT组高于ASC组.ROC曲线分析胸前导联移行区指数鉴别室性早搏起源有较高价值.结论 心电图呈左束支传导阻滞且Ⅱ、Ⅲ、aVF导联QRS主波向上的室性早搏,分析V1、V2导联R波时限指数、R/S波幅指数和胸前导联移行区指数可判断RVOT起源与ASC起源,指导射频消融治疗.     

Endocardial mapping of right ventricular outflow tract tachycardia using noncontact activation mapping

INTRODUCTION: Activation mapping and pace mapping identify successful ablation sites for catheter ablation of right ventricular outflow tract (RVOT) tachycardia. These methods are limited in patients with nonsustained tachycardia or isolated ventricular ectopic beats. We investigated the feasibility of using noncontact mapping to guide the ablation of RVOT arrhythmias. METHODS AND RESULTS: Nine patients with RVOT tachycardia and three patients with ectopic beats were studied using noncontact mapping. A multielectrode array catheter was introduced into the RVOT and tachycardia was analyzed using a virtual geometry. The earliest endocardial activation estimated by virtual electrograms was displayed on an isopotential color map and measured 33 +/- 13 msec before onset of QRS. Virtual unipolar electrograms at this site demonstrated QS morphology. Guided by a locator signal, ablation was performed with a mean of 6.9 +/- 2.2 radiofrequency deliveries. Acute success was achieved in all patients. During follow-up, one patient had a recurrence of RVOT tachycardia. Compared with patients (n = 21) who underwent catheter ablation using a conventional approach, a higher success rate was achieved by noncontact mapping. Procedure time was significantly longer in the noncontact mapping group. Fluoroscopy time was not significantly different in the two groups. CONCLUSION: Noncontact mapping can be used as a reliable tool to identify the site of earliest endocardial activation and to guide the ablation procedure in patients with RVOT tachycardia and in patients with ectopic beats originating from the RVOT.     

右室流出道特发性室速的射频消融治疗体会

目的 总结不同起源部位特发性右室流出道室性心动过速（ＩＲＶＯＴ）经导管射频消融（ＲＦＣＡ）治疗的方法和结果。方法 对３５例ＩＲＶＯＴ进行ＲＦＣＡ治疗,男性１８例、女性１７例,平均年龄（３９．１±１８．３）岁（８～７２岁）。其中１５例用常规方法消融,２０例用非常规方法消融,非常规方法加用８Ｆ ＳＢ０ Ｓｗａｒｔｚ鞘并在右室流出道放置参考电极。两者均采用起搏与激动标测来确定消融靶点。结果ＲＦＣＡ治疗ＩＲＶＯＴ的总成功率为８８．６％（３３／３５）,常规方法组成功率为８６．７％,复发率为１５．３％,非常规方法组分别为９０．１％和５．６％;常规方法组的导管操作时间为（７１±１２）ｍｉｎ,Ｘ线曝光时间平均为（３２±８）ｍｉｎ,非常规组分别为（４０± ９）ｍｉｎ和（１６ ±５）ｍｉｎ。ＩＲＶＯＴ起自右室流出道近间隔部１３例、游离壁１０ 例及介于两者之间 １２例。成功消融部位激动标测 Ｖ波提前 ＱＲＳ波 １８～３８ｍｓ,起搏标测与心动过速时１２导联心电图（ＥＣＧ）之ＱＲＳ波形态完全相同。结论ＩＲＶＯＴ非常规方法消融可以明显缩短导管操作时间、减少Ｘ线曝光时间及降低复发率;ＩＲＶＯＴ采用ＲＦＣＡ治疗具有较高的成功率和较低的复发率及并发症。     

Electrocardiographic predictors of failure and recurrence in patients with idiopathic right ventricular outflow tract tachycardia and ectopy who underwent radiofrequency catheter ablation

This study reports new electrocardiographic (ECG) predictors of radiofrequency catheter ablation failure and recurrence in idiopathic right ventricular outflow tract (RVOT) ventricular tachycardia (VT) or ectopy based on 91 consecutive patients. Procedural success and failure rates were 85% (77/91) and 15% (14/91), respectively. Twenty three percent (18/77) had recurrence during the follow-up period of 1 to 120 months (mean 56 +/- 31 months). Baseline RVOT VT/ectopy on 12-lead ECG taken prior to ablation from 91 patients were retrospectively analyzed. Ablation performed with RVOT ectopy (isolated ectopies, bigeminy, trigeminy, or couplets) as template arrhythmia was more likely to fail (30% vs. 8%, P =.02) as opposed to RVOT VT (sustained or nonsustained). VT/ectopy-QRS morphology variation was more observed in failed ablations (36% vs. 7%, P =.001). Significantly wider mean VT/ectopy QRS in leads I, II, AVR, V2, V3, V5, and V6 were noted in failed ablation group. Mean R wave amplitude reached statistical significance only in lead II (22.0 +/- 5.1 mV for failed vs. 17.8 +/- 5.2 mV for successful outcomes; P =.009). QRS morphologic variation (47% vs. 16%; P =.009) was the only statistically significant ECG to be more common in patients with arrhythmia recurrence. In conclusion, ablation with ectopy over VT as template arrhythmia, presence of QRS morphologic variation, wider mean QRS width, and taller mean R-wave amplitude in lead II were identified ECG predictors of failed RVOT VT/Ectopy ablation. The only ECG predictor of recurrence was the presence of RVOT VT or ectopy QRS morphologic variation.     

Ventricular fibrillation induced by a radiofrequency energy delivery for idiopathic right ventricular outflow tachycardia

We report a case of a patient with idiopathic right ventricular tachycardia who underwent radiofrequency (RF) catheter ablation. Shortly after the delivery of the RF energy, a nonsustained VT cluster occurred, and eventually resulted in VF, requiring cessation of the RF delivery and a 200 J transthoracic external cardioversion delivery.     

Cryocatheter ablation of right ventricular outflow tract tachycardia

INTRODUCTION: Cryocatheter techniques have been successfully applied to treat supraventricular tachycardia but there are no reports on their value in treating ventricular tachycardia (VT). We present our initial experience with cryocatheter ablation of right ventricular outflow tract (RVOT) tachycardia. METHODS AND RESULTS: Cryocatheter ablation was attempted in 14 patients (13 females, age 45.9 +/- 12.7 years) who were highly symptomatic due to frequent monomorphic ventricular extrasystole (VES) or nonsustained VT originating within the RVOT. A 9-Fr, 8-mm-tip cryocatheter was used for both mapping and ablation. Cryoablation was started after localizing the arrhythmic focus by pace and activation mapping. Ablation success, defined by complete disappearance of target VES/VT acutely and during a follow-up of 9.3 +/- 1.4 weeks, was achieved in 13 of 14 patients. Ablation was successful with local activation times of 35 +/- 4 ms, 5.8 +/- 3.3 applications, 18.8 +/- 7.5 minutes total cryo time, 9.4 +/- 4.2 minutes fluoroscopy time, and 66.9 +/- 26.1 minutes total procedure time, the latter two measures showing a reduction with number of patients treated. Three patients reported slight pain related to local pressure of the catheter on the RVOT wall. No pain was described related to delivery of cryothermal energy. CONCLUSIONS: Initial experience shows that focal VES/VT originating in the RVOT can be successfully treated using cryocatheter ablation. Acute and short term success rates, fluoroscopy times, and duration of procedure are comparable to conventional ablation techniques. A major advantage seems to be the virtual absence of ablation related pain.     

Reentrant ventricular tachycardia originating from the aortic sinus cusp: a case report

We report a case of idiopathic reentrant ventricular tachycardia (VT) originating from the left aortic sinus cusp. A prepotential preceding the QRS complex by 58 ms was recorded from the posterior right ventricular (RV) outflow tract. During VT entrainment observed by pacing from the midseptal RV, it initially was orthodromically captured with a long conduction time but then antidromically captured as the pacing cycle rate was increased. Pacing at that site failed to show concealed entrainment despite a postpacing interval similar to the VT cycle length. Radiofrequency catheter ablation abolished the VT in the left aortic sinus cusp where a prepotential preceding the QRS complex by 78 ms with a postpacing interval similar to the VT cycle length was recorded in addition to concealed entrainment. The findings suggest that, in this VT, a critical slow conduction zone is partially present extending from the left aortic sinus cusp to the posterior right ventricular outflow tract. The patient has remained free from VT recurrence after 5-month follow-up.     

Identification of unusual reentry circuit sites of nonischemic ventricular outflow tract tachycardia

Identification of Ventricular Outflow Tract Tachycardia. Background: Reentrant ventricular outflow tract (OT) tachycardia is rare in patients with nonischemic heart disease. The mechanism of ventricular tachycardia (VT) arising from the region of the aortic sinus of Valsalva (ASOV) is usually focal, rather than reentrant. Consequently, less is known about reentrant circuits in the OT and the aortic sinuses. The purpose of this study was to evaluate existence of reentry circuits in these areas using entrainment mapping techniques. Methods: We performed electrophysiological study in 51 consecutive patients with idiopathic or nonischemic symptomatic VT arising from the OT. Six of these patients were found to have VT of reentrant mechanism with 8 VT morphologies. Entrainment mapping, electroanatomical mapping (in 2 patients), and radiofrequency catheter ablation were performed. Results: Pacing entrained the VT at 93 sites, 52 of which were determined to be in the reentry circuit based on matching of the postpacing interval and VT cycle length. Of the reentry circuit sites, 6 were in the aortic sinus, 43 were below the aortic valve, and 3 were in the right OT below the pulmonary valve. Classification of reentry circuit sites identified 7 as exit, 1 as central‐proximal, 19 as inner loop, and 25 as outer loop sites. Catheter ablation terminated VT at 4 of the 6 aortic sinus sites and 4 of the 46 OT sites (P = 0.0006). Conclusions: We definitively demonstrated involvement of the ASOV in OT reentrant tachycardia using entrainment mapping. It may be useful for successful VT ablation to identify reentry circuit localization. (J Cardiovasc Electrophysiol, Vol. 23, pp. 179‐187, February 2012)     

主动脉无冠状窦内射频导管消融前间隔局灶性房性心动过速

目的报告经主动脉无冠状窦内射频消融8例前间隔局灶性房性心动过速(房速)。方法8例患者男性3例,女性5例,平均年龄(50．6±12．3)岁。阵发性房速病史(7．5±5．5)年。术中心房和心室刺激诱发房速,分别在右心房、左心房和主动脉无冠状窦内标测最早心房激动,并进行消融。结果心房刺激能反复诱发和终止8例患者的房速,房速的平均周长(329±66)ms。右心房和左心房的前间隔部位标测相对提前的心房激动,但多次消融未成功。主动脉无冠状窦内的心房激动较希氏束处的心房波提前(11．6±7．2)ms,放电1～2次于8s内终止8例房速。随访(10．2±4．8)个月,无一例房速复发。结论主动脉无冠状窦内可作为消融前间隔局灶性房速的一种新途径,尤其适用于在希氏束部位消融失败的患者。     

起源于主动脉窦内的房性心动过速、频发室性早搏的射频消融治疗

目的报道4例局灶性房性心动过速（房速）,3例频发室性早搏（室早）经主动脉途径在左冠窦和无冠窦内标测和射频消融的结果。方法对4例房速、3例频发室早进行常规心电图、心内电生理检查和射频消融治疗。结果4例阵发性房速患者的标测靶点位于主动脉窦内,在无冠窦成功消融;3例频发室早在左冠窦内标测及消融成功。术中无并发症,随访3～31个月,无1例复发。结论在主动脉无冠窦、左冠窦内射频消融是可行的且能达到安全、有效的治疗目的。尤其适用于在常规、经典部位消融失败的患者。     

主动脉左冠状窦内射频消融左心室流出道反复单形室性心动过速

目的　报道左心室流出道反复单形室性心动过速 (室速 )的心电图特点和射频消融结果。方法　对 11例无器质性心脏病的反复单形室速患者进行常规心电图、心内电生理检查和射频消融治疗。结果　室速呈不典型左束支阻滞伴心电轴右偏 ,Ⅰ导联为低振幅rs或rS波 ,V1 导联为rS或RS波 ,胸前导联R波移行区位于V2 或V3 导联 ,仅 1例的V5导联有小s波。起搏标测确定消融靶点位于主动脉左冠状窦内 ,在此部位成功射频消融 11例患者的室速。随访 (13± 7)个月 ,1例复发。结论　左心室流出道反复单形室速具有特殊的心电图表现 ,左冠状窦内射频消融能达到安全和有效的治疗目的。     

Catheter ablation of right ventricular outflow tract tachycardia: value of defining coronary anatomy

INTRODUCTION: Thermal damage to coronary arteries during catheter ablation has been previously reported. Coronary artery damage during LV outflow tract ventricular tachycardia is well recognized. However, the relationship of the coronary arteries to the RV outflow tract during catheter ablation has not been delineated. The purpose of this study was to define the relationship between the RV outflow tract and the coronary arteries utilizing arteriography, echocardiography, CT angiography, and gross anatomic pathology. METHODS: The relationship of the coronaries to the RV outflow tract was analyzed in three patients groups: Group 1: patients (n = 10) undergoing RV outflow tract ventricular tachycardia; Group 2: patients (n = 50) undergoing CT coronary angiography; Group 3: patients (n = 4) undergoing echocardiography during open heart surgery and intracardiac echocardiography (ICE) during catheter ablation of atrial fibrillation (n = 5). RESULTS: Group 1: The left main coronary artery was found to be 3.8 +/- 1.2 mm from the right ventricular outflow tract in patients undergoing ablation. Group 2: The minimum distance between the left main, left anterior descending, and right coronary artery to the RV outflow tract endocardial wall were 4.1 +/- 1.9 mm, 2.0 +/- 0.6 mm, and 4.3 +/- 1.9 mm (average +/- SD) respectively. Group 3: During open heart surgery using echocardiography, the minimum distance between the left main and the right coronary artery to the RV outflow tract were 3.4 +/- 0.35 mm and 2.0 +/- 0.1 mm, respectively. The distance between the let main coronary artery and the RVOT by ICE was 3.8 +/- 0.45 mm. CONCLUSIONS: The major coronary arteries lie in close proximity of the RVOT, and their anatomic course should be taken into consideration during ablation of ventricular tachycardias arising from the RV outflow tract.     

Catheter ablation of idiopathic ventricular tachycardia originating from myocardial extensions into a noncoronary aortic cusp

We present a 34-year-old woman with idiopathic ventricular tachycardia that resisted 2 previous attempts for catheter ablation and was successfully ablated in the myocardial extension within the noncoronary aortic cusp.     

主动脉窦部室性早搏与右心室流出道间隔部室性早搏心电图对比分析

目的：探讨主动脉窦部室性早搏（简称“室早”）和右心室流出道间隔部室早心电图特征的差别。方法选取12例右心室流出道间隔部室早（ A组）心电图作为对照,分析12例主动脉窦部室早（ B组）的心电图特征。结果与A组相比,B组V1、V2导联的R波时间指数增大[V1导联：（0．23±0．10） vs．（0．49±0．28）;V2导联：（0．24±0．12） vs．（0．57±0．23）;P均＜0．05]。 V1、V2导联的R／S波幅指数A组小于B组[ V1导联：（0．10±0．02） vs．（0．87±0．55）;V2导联：（0．21±0．14） vs．（1．13±1．49）,P均＜0．05]。 A组胸前导联R波移行在V3导联或其后,B组胸前导联R波移行在V1或V2导联。 A组V1、V2导联的R波移行指数小于B组[V1导联：（0．25±0．15） vs．（1．30±0．68）; V2导联：（0．31±0．20） vs．（1．71±1．14）, P均＜0．05]。结论主动脉窦部室早与右心室流出道间隔部室早在V1、V2导联R波时间指数、R／S波幅指数、胸前导联R波移行位置及移行指数上有明显的差别。