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.     

Catheter ablation for hemodynamically unstable monomorphic ventricular tachycardia

INTRODUCTION: Hemodynamic collapse precludes extensive catheter mapping to identify focal target regions in many patients with ventricular tachycardia (VT) associated with heart disease. This study tested the feasibility of catheter ablation of poorly tolerated VTs by targeting a region identified during sinus rhythm. METHODS AND RESULTS: Ablation was attempted in five patients, ages 44 to 59 years, with left ventricular ejection fractions of 0.15 to 0.20 and poorly tolerated VT causing multiple implantable defibrillator therapies (6 to 30 episodes/month). VT was due to prior infarction in three patients and nonischemic cardiomyopathy in two. Target regions were sought that met the following criteria: (1) evidence of slow conduction from fractionated sinus rhythm electrograms and stimulus-QRS delays during pace mapping, and (2) evidence that the region contains the reentrant circuit exit from pace mapping. In 4 of 5 patients, a target region was identified and radiofrequency lesions applied. Ablation abolished all recurrences of VT in 3 of 4 patients during follow-up of 14 to 22 months. There were no complications. CONCLUSION: Ablation of poorly tolerated VT is feasible in some patients by mapping during sinus rhythm and performing ablation over a region of identifiable scar that contains abnormal conduction and a presumptive VT exit.     

经主动脉无冠状窦内射频消融治疗房性心动过速

目的:报告经主动脉无冠状窦内射频消融6例局灶性房性心动过速(房速)的消融结果。方法:6例患者中男女各3例。阵发性房速病史(6±3)年。常规心电图、心内电生理,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,并进行射频消融。结果:心房刺激能反复诱发和终止6例患者的房速。心房内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。经主动脉无冠状窦内消融成功。平均随访3~17个月,无1例房速复发。结论:经主动脉无冠状窦消融前间隔房速是安全,有效的。     

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)     

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.     

反复单形室性心动过速的导管射频消融治疗

目的对18例反复单形室性心动过速的消融情况进行分析,并对消融同形室性早搏根治反复单形室性心动过速的可行性、安全性及有效性进行分析.方法18例患者,男性4例,女性14例,年龄19～45岁.心电图及动态心电图均有频发室性早搏和非持续性室性心动过速.征得患者的知情同意书后,电生理检查和消融一次进行,标测和消融同形的室性早搏,采用起搏标测和激动标测相结合的方法,确定室性心动过速的起源处(消融靶点).靶点定位后进行射频消融,温度50～60度,能量30～40W.即刻成功标准为放电后10 s内同形室性早搏和非持续性室性心动过速消失,且静脉滴注异丙肾上腺素不能诱发,观察30 min窦性心律稳定.随访成功标准为术后动态心电图24h室性早搏少于100个,无室性心动过速发作.结果18例患者起源于右心室流出道17例,其中1例存在2种形态的室性心动过速,分别于肺动脉瓣上及瓣下消融成功.起源于左心室流出道1例,于主动脉瓣上左Valsalva窦内消融成功.即刻成功17例.随访平均(23±14)个月,无心动过速复发16例,复发2例,1例于术后3个月复发,再次消融成功,另1例于术后6个月复发,未接受第2次消融.1例术后出现少量心包积液,经放置引流管后好转,无其他并发症.结论消融同形室性早搏是根治反复单形室性心动过速安全和有效的方法.     

Radiofrequency catheter ablation of postinfarction ventricular tachycardia from the proximal coronary sinus

Optimum strategy for radiofrequency (RF) catheter ablation of ventricular tachycardia (VT) after inferior wall myocardial infarction (MI) that originates from the posteroseptal process of the left ventricle is not known. We describe a case report of a 57-year-old man who developed recurrent post-MI VT with ECG morphology consistent with this type of VT (i.e., left bundle branch block pattern with predominant R waves from V2 to V6 and left-axis deviation). Endocardial mapping and entrainment during VT demonstrated a critical isthmus of the reentrant circuit in the proximal coronary sinus. RF application terminated VT and rendered it noninducible.     

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。     

Mapping and radiofrequency catheter ablation of the three types of sustained monomorphic ventricular tachycardia in nonischemic heart disease

INTRODUCTION: Sustained monomorphic ventricular tachycardia (VT) associated with nonischemic cardiomyopathy (CMP) is uncommon. Optimal approaches to catheter mapping and ablation are not well characterized, but they are likely to depend on the VT mechanism. The purpose of this study was to evaluate the mechanisms of sustained monomorphic VT encountered in nonischemic CMP and to assess the feasibility, safety, and efficacy of catheter radiofrequency ablation for treatment. METHODS AND RESULTS: Twenty-six consecutive patients with nonischemic CMP referred for management of recurrent VT were studied. In 16 (62%) patients, VT was related to a region of abnormal electrograms consistent with scar and the response to pacing suggested a reentrant mechanism. In 5 (19%) patients, VT was due to bundle branch or interfascicular reentry. In 7 (27%) patients, the VT mechanism was focal automaticity, 4 of whom had evidence of tachycardia-induced CMP. After catheter ablation targeting parts of reentrant circuits, VT was not inducible in 8 (53%) of 15 patients with scar-related reentry, was modified in 5 (33%) patients, and still was inducible in 2 (13%) patients. Ablation was successful in 5 of 5 patients with bundle branch reentry and in 6 of 7 patients with a focal automaticity mechanism. Overall, catheter ablation abolished clinical recurrence of VT in 20 (77%) of 26 patients during a follow-up of 15 +/- 12 months. CONCLUSION: Three different mechanisms of VT are encountered in patients with nonischemic CMP. The mapping and ablation approach varies with the type of VT. In this selected population, the overall efficacy was 77%.     

Retrograde aortic access during ventricular tachycardia ablation: Indications,techniques, and challenges

The retrograde aortic (RA) route is a widely used access route for mapping and ablation of ventricular tachycardias (VT) arising from the left ventricular endocardium. With the expanding role of VT ablation in patients with significant comorbidity, the choice between the RA and transseptal access routes is an increasingly important consideration. An individualized decision based on the location of the arrhythmogenic substrate, vascular anatomy, aortic valve morphology, and operator experience is necessary when deciding on the optimal access route. Among patients with challenging vascular anatomy, growing experience from structural interventions such as transcatheter aortic valve replacements and peripheral vascular interventions has provided valuable insights into techniques for safe retrograde access. The present review focuses on patient selection for RA access, potential complications associated with the technique, and optimal approaches for access in patients with challenging vascular or aortic valve anatomy.     

Mapping and ablation of ventricular tachycardia with the aid of a non-contact mapping system

OBJECTIVE: Treatment of ventricular tachycardia (VT) in coronary heart disease has to date been limited to palliative treatment with drugs or implantable defibrillators. The results of curative treatment with catheter ablation have proved disappointing because the complexity of the VT mechanism makes identification of the substrate using conventional mapping techniques difficult. The use of a mapping technology that may address some of these issues, and thus make possible a cure for VT with catheter ablation, is reported. PATIENTS AND INTERVENTION: The non-contact system, consisting of a multielectrode array catheter (MEA) and a computer mapping system, was used to map VT in 24 patients. Twenty two patients had structural heart disease, the remainder having "normal" left ventricles with either fasicular tachycardia or left ventricular ectopic tachycardia. RESULTS: Exit sites were demonstrated in 80 of 81 VT morphologies by the non-contact system, and complete VT circuits were traced in 17. In another 37 morphologies of VT 36 (30)% (mean (SD)) of the diastolic interval was identified. Thirty eight VT morphologies were ablated using 154 radiofrequency energy applications. Successful ablation was achieved by 77% of radiofrequency within diastolic activation identified by the non-contact system and was significantly more likely to ablate VT than radiofrequency at the VT exit, or remote from diastolic activation. Over a mean follow up of 1.5 years, 14 patients have had no recurrence of VT and only two target VTs have recurred. Five patients have had recurrence of either slower non-sustained, undocumented or fast non-target VT. Five patients have died, one from tamponade from a pre-existing temporary pacing wire, and four from causes unrelated to the procedure. CONCLUSION: The non-contact system can safely be used to map and ablate haemodynamically stable VT with low VT recurrence rates. It is yet to be established whether this system may be applied with equal success to patients with haemodynamically unstable VT.     

无冠窦起源房速的电生理特征与射频消融

目的进一步分析起源于主动脉无冠窦房性心律失常的心电生理特征及射频消融治疗。方法11例患者经心内电生理检查和射频消融证实的起源于主动脉无冠窦局灶性房速,对其临床特征,心电生理特点及射频消融进行分析。结果无冠窦房速大多为女性,表现为阵发性,为心房或心室程序刺激诱发和终止。所有患者房速心电图P波窄而低幅,Ⅱ,Ⅲ,aVF和v,导联P波负正双向,Ⅰ,aVL导联直立,V2～V6导联P波负向。心内最早激动位于希氏束远端,并领先于体表P波起始（15±3）ms。无冠窦内标测最早激动等于或早于希氏束远端,局部电位特征为大A小V（或大V）,无希氏束电位,11例患者无冠窦内放电均在8秒内终止心动过速,均无并发症,无抗心律失常药物随访12±5月所有患者均无心动过速复发。结论主动脉无冠窦房速有独特的临床特征,心电图特征及心房内激动顺序,长期随访这类房速射频消融有良好的治疗效果。     

起源于左心室游离壁的单形室性心动过速和早搏的射频导管消融

目的 起源于左心室游离壁的室性心动过速(ventricular tachycardia, VT)及早搏(premature ventricular contraction, PVC)是较少见的心律失常,本文报道对其进行标测及射频导管消融的初步经验。方法 11例患者(男性9例,女性2例),平均年龄(37.3±17.2)岁。其中7例有持续性VT,4例为短阵非持续性单形VT和/或频发PVC,体表心电图均为右束支阻滞(RBBB)和心电轴右偏。3例患者伴明显的左心室扩大及充血性心力衰竭。对全部患者进行了左心室电生理标测,其中6例采用了心内非接触式标测。在标测到的最早激动部位进行温度控制下的射频导管消融。结果 11例患者均标测到自发的单形VT或PVC。其室性心律的平均周长(443.3±76.6)ms。全部室性心律均起源于左心室游离壁,其中2例位于偏前的高位近二尖瓣环处,2例位于后外侧游离壁中、高位,6例源于游离壁中高位,1例位于游离壁中下部。VT或PVC最早电位平;啕领先体表心电图(31.8±11.8)ms。全部患者的消融均获得即时成功,且不再服用抗心律失常药物,平均随访(11.8±8.0)个月,仅1例VT患者有单形PVC(<1000次/24h),3例左心室增大者均有明显缩小,其中1例基本恢复正常。结论 单形VT或PVC可发生于无缺血性心脏病的患者,表现为右束支阻滞和心电轴右偏,其频率较慢,可被射频导管消融消除。     

Simultaneous existence of sustained double chamber tachycardias originating from the aortic sinus of Valsalva

Monomorphic ventricular tachycardia is basically a benign phenomenon in patients without structural heart disease. The focal source of the tachycardia is usually located in the right ventricular outflow tract and more rarely in the left ventricular outflow tract. Aortic sinus of Valsalva (ASV) is a well-known source of atrial and ventricular tachycardias. We report a case with simultaneous existence of sustained atrial and ventricular tachycardias originating from ASV, which was successfully treated with radiofrequency catheter ablation.     

Non-contact mapping to guide catheter ablation of untolerated ventricular tachycardia.

AIMS: The role of a novel non-contact mapping system (ESI 3000, Endocardial Solutions) to guide radiofrequency catheter ablation of untolerated ventricular tachycardia was investigated in 17 patients; 11 with prior myocardial infarction, three with arrhythmogenic right ventricular dysplasia, and three with idiopathic dilated cardiomyopathy. METHODS: Twenty-seven monomorphic ventricular tachycardias were induced (mean cycle 320+/-60 ms, range 230-450 ms), mapped for 15-20 s, and terminated by overdrive pacing or DC shock. Off-line analysis of isopotential activation mapping was performed to identify the diastolic pathway and/or the exit point of the ventricular tachycardia reentry circuit. Radiofrequency current was applied to create a line of block across the diastolic pathway or around the exit point. RESULTS: All 27 ventricular tachycardias were mapped with the non-contact system. The endocardial exit point (-7+/-15 ms before QRS onset) was defined in 21/21 postinfarction ventricular tachycardias, in 3/3 arrhythmogenic right ventricular dysplasia and in 1/3 idiopathic dilated cardiomyopathy ventricular tachycardias, respectively. The diastolic pathway (earliest endocardial diastolic activity: -65+/-49 ms before QRS onset) was identified in 17/21 postinfarction ventricular tachycardias, in 1/3 arrhythmogenic right ventricular dysplasia and in 1/3 idiopathic dilated cardiomyopathy ventricular tachycardias, respectively. Catheter ablation was performed in 25/27 ventricular tachycardias (93%) in 15/17 patients (88%): 16/25 ventricular tachycardias (64%) were successfully ablated in 10/17 patients (59%). Catheter ablation was not performed in two patients or proved unsuccessful in five patients. At a follow-up of 15+/-5 months, there was no recurrence of documented ventricular tachycardia in all 10 patients with successful catheter ablation; in two of them a previously non-documented ventricular tachycardia occurred. A high recurrence of ventricular tachycardia was observed in patients with a failed procedure (5/7: 71%). No major complication or death occurred. CONCLUSIONS: Non-contact mapping can be effectively used to map and guide radiofrequency catheter ablation of untolerated ventricular tachycardias. Given the favourable acute and clinical long-term results, this approach proves to be more effective in patients with postinfarction ventricular tachycardias, in comparison to patients with arrhythmogenic right ventricular dysplasia and idiopathic dilated cardiomyopathy.     

Magnetic electroanatomic mapping of an atrial tachycardia requiring ablation within the coronary sinus

We describe a focal atrial tachycardia (AT) originating from the region of the inferoposterior mitral annulus in which ablation at the site of earliest endocardial activation during AT was unsuccessful. Three-dimensional electroanatomic mapping identified the earliest atrial activation within the coronary sinus. Radiofrequency energy delivered at this site within the CS terminated this tachycardia without any complications, suggesting an origin within the CS. To our knowledge, this is the first time a three-dimensional, high-density activation map of such a tachycardia has been reported.     

窦性心律下非接触式标测指导线性消融治疗特发性左心室室性心动过速

目的 大多数特发性左心室室性心动过速(ILVT)是起源于左后分支(LPF)浦肯野纤维网的折返性心动过速,因而利用非接触式标测系统在窦性心律下标测LPF并经其导航系统指导线性消融治疗ILVT是可行的,现介绍此方法的安全性和有效性。方法 6例患者,1例既往接受3次射频导管消融术,临床呈无休止发作;1例为常规消融术后1个月复发;4例为常规首次接受射频导管消融术患者。其中男性5例,女性1例,平均年龄15～58(34.00±16.26)岁。常规电生理检查明确ILVT诊断后,将球囊电极导管经股动脉逆行送入至左心室心尖部,构建几何构形后建立窦性心律的等电位图。结果 窦性冲动沿希氏束向下传导,在间隔中部不到心尖处激动局部间隔心肌并很快激动整个左心室。局部虚拟电图显示,在间隔部激动的每个QRS波前均有高频、低幅的电位,该电位与QRS波之间的距离随激动的推移而逐渐缩短;心室激动爆发点处的局部电图呈QS型。在心室激动爆发点上方1 cm处于LPF区域作垂直于LPF激动方向的线性消融,消融后所有患者均出现不同程度的左后分支阻滞图形,线性消融的平均放电次数为4～8(5.66±1.50)次,消融完毕后心动过速均不能诱发。平均随访7～13(10.00±2.76)个月,所有患者均无心动过速复发。结论 窦性心律下标测LPF并指导线性消融治疗ILVT不仅安全有效     

起源于左主动脉窦的室性心律失常的心电生理特点和消融治疗

目的报道21例起源于左主动脉窦的室性心律失常的心电生理特征和射频消融疗效。方法分析术前体表心电图(ECG)和Holter心电图室性早搏(VPB)或室性心动过速(VT)的形态特点,测量V1导联r波振幅和时限,计算r与QRS波的振幅和时限比值。术中在自发VPB或VT时标测主动脉窦,以局部室波最早部位放电消融,并进行冠状动脉造影,测量消融靶点距左冠状动脉口的距离。结果21例均有频发VPB,8例有反复短阵VT。VPB或VT在Ⅱ、Ⅲ、aVF导联为高大R波,V1导联r波振幅为QRS波的1/3或以上,r波时限87.5±9.5 m s,为QRS波时限的1/2以上。V3导联多为R s形,V5、V6导联无S波。有效消融靶点局部电图室波明显超前ECG的QRS波(36.2±12.2 m s),距左冠状动脉口部1 cm左右。有效靶点放电2~8 s VPB消失或VT终止。结论起源于左主动脉窦的VPB或VT其Ⅱ、Ⅲ、aVF导联为高大R波,V1导联r波振幅高(≥1/3QRS波),时限宽(≥1/2QRS波);主动脉窦激动顺序标测可安全有效地指导消融治疗。