体表心电图特征对特发性右心室流出道室性心动过速和室性早搏起源点的定位价值

目的 起源于右心室流出道(RVOT)不同位点的室性心动过速(VT)具有相应的心电图表现,本研究旨在摸索一种相对简单的根据体表心电图进行定位的方法 .方法 将RVOT分为游离壁和间隔而两大区,其中间隔面又分为9个区域.共320例RVOT-VT患者中,对213例既往消融成功患者的靶点与体表12导联心电图中QRS波形态之间的关系进行分析,并在消融前前瞻性地对另外107例患者的消融靶点进行预测,以检验其定位价值.结果 I导联对RVOT起源的VT有特殊的定位价值.在间隔面前部起源时,I导联以负向波为主,多为QS、Qr及rS型,随着起源点从前向后、从上向下,R波逐渐升高,其中起源于间隔侧中带(2、5、8区)时,以"M"型居多,在后壁时则表现为R波且有切迹.游离壁起源者的QRS时限明显延长,I和aVL导联的R波较间隔起源者高,而下壁导联的R波均较间隔的低(P<0.05).在前瞻性分析中,这些参数的敏感度、特异度、阳性和阴性预测值均较高.结论 RV-OT不同部位起源的VT有相应的心电图特征,其中I导联形态尤其具有定位价值,为RVOT心律失常起源提供了简便的定位标准.     

His束旁特发性室性早搏的心电图特点及射频消融

目的回顾分析His束旁室性早搏(PVCs)的心电图(ECG)特点和射频消融方法。方法选择2005年至2011年5月间的7例His束旁的PVCs,并与136例起源于右室流出道(RVOT)的PVCs的12导联ECG进行对比分析并总结射频消融治疗的经验。结果与起源于RVOT的PVCs ECG对比,起源于His束旁PVCs的12导联ECG中aVL导联多表现为振幅较低,多以R波为主。V1导联多为QS型(85.7%),胸前导联移行区多发生于V2～V3导联(71.4%)。7例均在His束电极附近标测到最早心室激动。5例一次消融成功;1例1周后再次消融成功;1例因消融电极几乎与His电极重叠而放弃手术。结论 His束旁PVCs在体表ECG上完全可以进行鉴别,射频消融术可以根治此类PVCs。     

射频导管消融治疗的特发性室性心律失常心电图特征分析

目的：探讨不同起源的特发性室性期前收缩（PVCs）和（或）室性心动过速（VT）的心电图特征,提出鉴别流程。方法根据射频导管消融PVCs/VT有效靶点或心室最早激动点的X线胸片进行定位,分析不同起源PVCs/VT的12导联心电图QRS波群。结果828例接受导管消融,580例起源于右心室,248例起源于左心室,左、右心室起源者胸导联移行指数＜0的分别占97.58%及7.24%;左和右心室流出道起源者下壁导联多数呈R型,V1上,多数右心室流出道起源者呈rS型,右室间隔起源呈QS型,主动脉瓣上起源者常呈rS或RS型;下壁导联上,左前分支起源者常呈qR型,左后分支起源者常呈rS型。结论结合体表心电图胸导联移行指数、下壁导联和V1上的QRS波群特征可初步判断特发性PVCs/VT的起源部位。     

右心室间隔部希氏束附近室性期前收缩心电图与射频消融

目的 报道右心室流入道间隔部希氏束附近起源室性期前收缩体表心电图特征及射频消融效果。方法 无器质性心脏病频发性室性期前收缩5例,分析其12导联体表心电图室性期前收缩特点;病人接受心内电生理检查,于右心室流入道行激动与起搏标测,以心室激动较体表QRS波提早、消融导管远端起搏图形与体表心电图室性期前收缩相似部位为消融靶点。结果 室性期前收缩QRS波形态：5例病人Ⅰ导联和Ⅱ导联QRS波均呈R型,Ⅲ导联、aVF导联以低振幅波为主,V1导联均呈QS型,胸导联较早转变成qR或R型（发生于V2或V3）,V5、V6均呈高R型;室性期前收缩QRS波时限为110～120ms。5例病人分别于前间隔（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、后间隔部病人室性期前收缩均消失,中间隔病人消融失败。无房室传导阻滞并发症。随访8～30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 右心室流入道间隔部希氏束附近起源室性期前收缩体表心电图具有明显的特征,认识这些特征有助于导管标测与射频消融,消融此部位室性期前收缩安全、有效。     

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.     

Electrocardiographic (ECG) clues to differentiate idiopathic right ventricular outflow tract tachycardia (RVOTT) from arrhythmogenic right ventricular cardiomyopathy (ARVC)

Introduction

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a genetic cardiomyopathy that most commonly affects young adults. The most commonly observed reason of death in patients suffering from ARVC/D is sudden cardiac death (SCD). On the other hand, idiopathic right ventricular outflow tract tachycardia (RVOT VT) usually has a benign course. Both of the entities may have ventricular tachycardia (VT) with left bundle branch block (LBBB) pattern and inferior axis. We tried to propose new discriminating electrocardiographic indices for differentiation of foretold entities.

Material and method

This was a retrospective study. We reviewed records of patients admitted between 2003 and 2012 with the diagnosis of either ARVC/D or RVOT VT that presented with VT (LBBB morphology).

Result

A total of fifty nine patients (30 RVOT VT and 29 ARVC/D) were enrolled. In ARVC/D group, men were dominant while the reverse was true of RVOT VT. Palpitation was more common in the RVOT VT group (90% vs. 66.7%), but aborted SCD and sustained VT were more common in ARVC/D group. The new ECG criteria proposed by us mean QRS duration in V1–V3, QRS difference in right and left precordial leads, S wave upstroke duration, JT interval dispersion, QRS and JT interval of right to left precordial leads were all significantly longer in ARVC/D when compared to RVOT VT patients (p < 0.001).

Conclusion

The proposed ECG criteria can be used for non-invasive diagnosis of ARVC/D and incorporation in the future updates of ARVC/D task force criteria.     

Ventricular tachycardias mimicking those arising from the right ventricular outflow tract

INTRODUCTION: Ablation of ventricular tachycardia (VT) arising from the right ventricular outflow tract (RVOT) has proven highly successful, yet VTs with similar ECG features may originate outside the RVOT. METHODS AND RESULTS: We reviewed the clinical, echocardiographic, and ECG findings of 29 consecutive patients referred for ablation of monomorphic VT having a left bundle branch block pattern in lead V1 and tall monophasic R waves inferiorly. Nineteen patients (group A) had VTs ablated from the RVOT, and 10 patients (group B) had VTs that could not be ablated from the RVOT. The QRS morphology during VT or frequent ventricular premature complexes was the only variable that distinguished the two groups. During the target arrhythmia, ECGs of group B patients displayed earlier precordial transition zones (median V3 vs V5; P < 0.001), more rightward axes (90 +/- 4 vs 83 +/- 5; P = 0.002), taller R waves inferiorly (aVF: 1.9 +/- 1.0 vs 2.4 +/- 0.5; P = 0.020) and small R waves in lead V1 (10/10 vs 9/19; P = 0.011). Radiofrequency catheter ablation from the RVOT failed to eliminate VT in any group B patient, but ablation from the left ventricular outflow tract (LVOT) eliminated VT in 2 of 6 patients in whom left ventricular ablation was attempted. CONCLUSION: The absence of an R wave in lead V1 and a late precordial transition zone suggest an RVOT origin of VT, whereas an early precordial transition zone characterizes VTs that mimic an RVOT origin. The latter VTs occasionally can be ablated from the LVOT. Recognition of these ECG features may help the physician advise patients and direct one's approach to ablation.     

Electrocardiographic pattern as a guide for management and radiofrequency ablation of idiopathic ventricular tachycardia

BACKGROUND: Idiopathic ventricular tachycardia (VT) often originates from the right ventricular outflow tract (RVOT), but foci deep to the endocardium, in the epicardium, or in the left ventricle are not uncommon. Although these extra-RVOT foci can be targeted with ablation, risks involved are higher and success rates lower. Simple electrocardiographic (ECG) criteria allowing (1) discrimination of RVOT foci from extra-RVOT foci and (2) assessment of the chance of success of a right heart ablation procedure are desirable. METHODS: Twenty-five consecutive patients referred for radiofrequency (RF) ablation of idiopathic VT or severely symptomatic idiopathic ventricular premature contractions were included. Localization of VT origin and success rates of VT ablation in the RVOT were analyzed according to the ECG pattern. RESULTS: The analysis of the R wave in V2 was the strongest single predictor of whether the VT had an RVOT or an extra-RVOT origin. An R wave amplitude < or =30% of the QRS amplitude designated the VT focus in the RVOT with positive and negative predictive values of 95 and 100%, respectively. Analysis of R wave duration in V2 had similar predictive values, whereas the R/S transition zone in precordial leads had slightly lower predictive values. Seventeen of 20 arrhythmias (85%) with an R wave amplitude < or =30% of the QRS amplitude in V2 could be successfully abolished by an exclusively right heart procedure. CONCLUSIONS: The analysis of ECG pattern makes it possible to guide the management of patients with idiopathic VT in predicting the arrhythmias that can be safely targeted with RF ablation from the RVOT with high success rates.     

Electrocardiographic and electrophysiologic characteristics of ventricular tachycardia originating within the pulmonary artery

OBJECTIVES: We investigated the electrocardiographic (ECG) and electrophysiologic characteristics of ventricular tachycardia (VT) originating within the pulmonary artery (PA). BACKGROUND: Radiofrequency catheter ablation (RFCA) is routinely applied to the endocardial surface of the right ventricular outflow tract (RVOT) in patients with idiopathic VT of left bundle branch block morphology. It was recently reported that this arrhythmia may originate within the PA. METHODS: Activation mapping and ECG analysis were performed in 24 patients whose VTs or ventricular premature contractions (VPCs) were successfully ablated within the PA (PA group) and in 48 patients whose VTs or VPCs were successfully ablated from the endocardial surface of the RVOT (RV-end-OT group). RESULTS: R-wave amplitudes on inferior ECG leads, aVL/aVR ratio of Q-wave amplitude, and R/S ratio on lead V(2) were significantly larger in the PA group than in the RV-end-OT group. On intracardiac electrograms, atrial potentials were more frequently recorded in the PA group than in the RV-end-OT group (58% vs. 12%; p < 0.01). The amplitude of local ventricular potentials recorded during sinus rhythm within the PA was significantly lower than that recorded from the RV-end-OT (0.62 +/- 0.56 mV vs. 1.55 +/- 0.88 mV; p < 0.01). CONCLUSIONS: Ventricular tachycardia originating within the PA has different electrocardiographic and electrophysiologic characteristics from that originating from the RV-end-OT. When mapping the RVOT area, the catheter may be located within the PA if a low-voltage atrial or local ventricular potential of <1-mV amplitude is recorded. Heightened attention must be paid if RFCA is required within the PA.     

起源于主动脉窦内反复单形室性心动过速和/或频发室性早搏的心电图特征及射频消融治疗

探讨起源于主动脉窦内的反复单形室性心动过速(简称室速)和/或频发室性早搏(简称室早)的心电图特点和射频消融治疗。分析35例该类患者的室速和频发室早的心电图、心内电生理检查和射频消融治疗情况。结果:室性心律失常起源于左冠状动脉窦(简称左冠窦)的30例、无冠状动脉窦3例和主动脉根部左冠窦下2例。左冠窦的心电图特点:Ⅰ和aVL导联为rs、rS或QS波形,Ⅱ、Ⅲ和aVF导联为R波形,胸导联R波移行区在V2或V3导联,V5、V6导联为高振幅R波,无S波;V2导联R高度/S高度比值1.29±0.36。主动脉根部左冠窦下起源的心电图特点:和左冠窦起源室性心律失常的心电图特点基本相同,但V5、V6导联有S波。无冠状动脉窦起源的心电图特点:Ⅰ和aVL导联为Rs或R波形,Ⅱ、Ⅲ和aVF导联为R波形,胸导联R波移行区在V3导联。34例消融成功,手术操作时间65~120min,X光曝露时间12~30min。1例出现冠状动脉前降支急性闭塞。随访2~53个月,无复发病例。结论:起源于主动脉窦内的室速和/或频发室早有其独特的心电图表现,射频消融能安全、有效地根治此类心律失常。     

右室流出道室性期前收缩的心电图特征及射频消融治疗

目的:探讨右室流出道室性期前收缩(室性早搏,室早)的心电图特征和评价单导管法消融单形性右室流出道室性早搏的有效性、安全性和实用性。方法:对52例心脏结构正常的右室流出道单形性室早的心电图特征进行分析并行单导管射频消融。采用起搏标测法,以起搏时与自发室性早搏形态波形态完全相同点为消融靶点。结果:右室流出道的室性早搏体表12导联心电图特征,呈完全性左束支阻滞形态,Ⅰ导联呈rs、m、QS及R型,aVR、aVL均呈QS型,Ⅱ、Ⅲ、aVF、V5~6导联均呈单向R波型,胸前导联R波移行区常在V3、V4导联之后。成功消融结果显示26例室早起源右室流出道间隔部:其中前间隔7例、中间隔5例、后间隔14例,游离壁21例:其中前游离壁6例、后游离壁15例,希氏束附近1例,肺动脉瓣下1例。消融即刻成功率94%(49/52),未成功的3例。手术操作时间30~150 min,X线曝光时间5~29 min。术后随访2~48个月无复发。结论:起源于右室流出道的室性早搏有其独特的心电图表现,单导管射频消融可有效、安全地消融心脏结构正常的右室流出道单形性室性早搏。     

右室流出道不同部位起搏体表心电图的形态特征研究

右室流出道 (RVOT)是一个相对较大的区域 ,事先定位这一区域内心律失常的起源部位有助于指导射频消融治疗。为评估根据体表 1 2导联心电图定位起源于RVOT不同部位的心律失常 ,选择 90例无器质性心脏病的室上性心动过速患者 (57例房室折返性心动过速、33例房室结折返性心动过速 )进行研究。将RVOT分为游离壁和间隔 ,按距肺动脉瓣的距离由近至远再分上、中、下三部 ,共 6个区。成功进行射频消融后 ,于RVOT不同部位进行起搏 ,并同时记录 1 2导联体表心电图。结果 :在间隔和游离壁起搏时 ,Ⅰ、aVL导联表现为特征性变化。间隔部起搏时Ⅰ导联QRS波形态多变 ,aVL导联QRS波主要呈QS型 ,QRSⅠ/QRSaVL<1 ;在游离壁起搏时 ,Ⅰ导联QRS波主要呈R型 ,aVL导联QRS波形态多变 ,QRSⅠ/QRSaVL>1。Ⅰ、aVL导联QRS波形态特征对判断游离壁和间隔具有较高的特异度和灵敏度。在RVOT上、中、下位起搏时 ,V3导联呈特征性变化 ,分别主要呈R、RS(R/S >1 )、rS(r/S <1 )型。V3导联QRS波形态特征对判断RVOT的上、中、下位具有较高的特异度和灵敏度。结论 :可根据体表心电图图形特征 ,定位RVOT起源的心律失常部位     

左束支阻滞型特发性室性心动过速的心电图特征对射频消融成功的影响初探

对心电图呈左束支阻滞型的特发性室性心动过速 (简称室速 )的临床特点和心电图进行分析 ,以了解哪些因素可以预测此类患者从右室流出道行射频消融的成功率。对 2 6例特发性室速的患者进行电生理检查和射频消融手术 ,全部患者室速时的心电图呈左束支阻滞。结果 :2 6例中 ,2 2例于右室流出道进行了成功消融 ,成功和未成功消融的患者临床特征和电生理无明显区别 ,成功消融的患者中胸前V1 导联心电图呈rS型 (1 2例 )和QS型 (1 0例 ) ,而 4例未成功者 ,V1 导联均呈rS型 ,其中 2例经主动脉于左冠状窦消融成功。在成功与未成功消融患者中 ,V1 导联有无R波无明显区别 ,但V1 导联无R波预示室速可以从右室流出道成功消融 ,成功消融的室速患者胸前导联的平均移行区在V4导联 ,而未成功患者胸前导联的移行区在V3 或V2 导联。结论 :某些心电图呈左束支阻滞 ,且额面电轴正常或右偏的特发性室速患者不能成功从右室流出道消融 ,V1 导联有r波且移行区在V3 导联或之前者提示此类心电图特征的室速可能非起源于右室流出道 ,部分可能起源于左室流出道     

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.     

How to diagnose,locate, and ablate coronary cusp ventricular tachycardia

INTRODUCTION: Although radiofrequency energy usually is applied to the most favorable endocardial site in patients with outflow tract ventricular tachycardia, there are still some patients in whom the tachycardia can be ablated only from an epicardial site. We established the characteristics and technique of catheter ablation from both the left and right coronary cusps to cure left ventricular outflow tract ventricular tachycardia. METHODS AND RESULTS: We studied 15 patients in whom VT was thought to originate from the coronary cusp by both activation and pace mapping after precise mapping of the right ventricle, left ventricle, pulmonary artery, coronary cusps, and anterior interventricular vein. Twelve-lead ECG analysis revealed an S wave on lead I, tall R wave on leads II, III, and aVF, and no S wave on either lead V5 or V6. Precordial R wave transition occurred on leads V1 and V2. The earliest ventricular electrogram at a successful ablation site was recorded 35+/-12 msec before QRS onset and 19+/-15 msec earlier than the earliest ventricular electrogram recorded from the anterior interventricular vein. Almost identical pace mappings were obtained from the coronary cusp. Catheter tip temperature was maintained at 55 degrees C during energy delivery, and the distance from the tip to the ostium of each left and right coronary artery was > 1.0 cm by coronary angiography. CONCLUSION: Left ventricular outflow tract VT that could not be ablated from an endocardial site could be safely eliminated by radiofrequency application to the left and right coronary cusps.     

Electrocardiographic patterns of superior right ventricular outflow tract tachycardias: distinguishing septal and free-wall sites of origin

INTRODUCTION: The superior right ventricular outflow tract (RVOT) septum and free wall are common locations of origin for outflow tract ventricular tachycardias (VT). We hypothesized that (1) unique ECG morphologies of pace maps from septal and free-wall sites in the superior RVOT could be identified using magnetic electroanatomic mapping for accurate anatomical localization; and (2) this ECG information could help facilitate pace mapping and accurate VT localization. METHODS AND RESULTS: In 14 patients with structurally normal hearts who were undergoing ablation for outflow tract VT, a detailed magnetic electroanatomic map of RVOT was constructed in sinus rhythm, then pace mapping was performed from anterior, mid, and posterior sites along the septum and free wall of the superior RVOT. Pace maps were analyzed for ECG morphologies in limb leads and transition patterns in precordial leads. Monophasic R waves in inferior leads for septal sites were taller (1.7 +/- 0.4 mV vs 1.1 +/- 0.3 mV; P < 0.01) and narrower (158 +/- 21 msec vs 168 +/- 15 msec; P < 0.01) compared with free-wall sites; lacked "notching" (28.6% vs 95.2%; P < 0.05); and showed early precordial transition (by lead V4; 78.6% vs 4.8%; P < 0.05). A positive R wave in lead I also distinguished posterior from anterior septal and free-wall sites. Based on QRS morphology in limb leads and precordial transition pattern (early vs late), in a retrospective analysis, a blinded reviewer was able to accurately localize the site of origin of clinical arrhythmia (the successful ablation site on the magnetic electroanatomic map) in 25 of 28 patients (90%) with superior RVOT VT. CONCLUSION: Pace maps in the superior RVOT region manifest site-dependent ECG morphologies that can help in differentiating free-wall from septal locations and posterior from anterior locations. Despite overlap in QRS amplitude and duration, in the majority of patients a combination of ECG features can serve as a useful template in predicting accurately the site of origin of clinical arrhythmias arising from this region.     

右室流出道室性心律失常的射频导管消融体会

目的报道右室流出道(RVOT)室性心律失常的射频导管消融(RFCA)体会。方法43例RVOT室性心律失常患者男18例、女25例,年龄39.2±15.1(13～67)岁。经血液生化、胸片、心脏彩超等检查证实无器质性心脏病证据。其中室性心动过速(VT)8例,室性早搏(PVC)35例。38例采用传统的起搏与激动标测。5例VT是在非接触标测系统EnSite3000指导下进行消融治疗的。结果①间隔部起源40例,游离壁起源3例。42例成功,1例失败,成功率97.7%,9例复发,再次标测消融后成功。②RVOT起源的VT和PVC具有典型的心电图特征,表现为典型的左束支传导阻滞型伴电轴右偏。RVOT的起源点不同,其12导联心电图特征不同,Ⅰ、Ⅱ、Ⅲ和aVF导联呈RR′型,V1～V3具有深S波是游离壁起源的特征。③1例术中出现急性心包压塞,其心电图虽具有RVOT起源的特征,但Ⅱ、Ⅲ和aVF导联R波振幅异常增高。结论RVOT室性心律失常具有典型的心电图和电生理特征,RFCA是一种安全、有效的治疗方法。EnSite3000非接触标测系统定位快速准确,适用于血流动力学不稳定的复杂性心律失常的标测。     

起源于左右心室流出道心动过速和早搏的射频导管消融治疗

目的 探讨射频导管消融（RFCA）治疗心室流出道特发性室性心动过速（室速）和室性早搏（室早）的临床效果、心电图及电生理特征。方法 58例患者中室速10例,室早48例。起源于右室流出道（RVOT）43例,左室流出道（LVOT）15例,其中起源于主动脉瓣上Valsalva左冠窦（LSV）12例。5例RVOT室速是在非接触标测系统Ensite3000指导下进行消融的。结果 （1）58例患者中55例成功,3例失败,9例复发。（2）其中1例患者术中出现急性心包压塞。（3）起源心室流出道的室速和室早具有典型的心电图特征,其中Ⅱ、Ⅲ、aVF导联单向R波是流出道室性心律失常的共同特点。（4）V1或V2导联的R波时限指数与R／S波幅指数可作为区别LSV与RVOT室速和室早的有效指标。结论 射频导管消融治疗心室流出道特发性室性心律失常是一种安全、有效的方法。非接触标测系统对于血流动力学不稳定的复杂性室性心律失常的标测与治疗具有重要的意义。     

Electrocardiographic characteristics of premature ventricular contractions in subjects with type 1 pattern of Brugada syndrome

Background

The ECG characteristics of premature ventricular contractions (PVCs) in subjects with Brugada syndrome (BrS) phenotype were investigated.

Methods and results

A total of 96 patients with type 1 ECG pattern of BrS were screened for PVCs. The study population consisted of 10 male individuals (mean age 41.9 ± 5.6 years) with spontaneous (n = 2) or drug-induced (n = 8) type 1 ECG phenotype of BrS and PVCs. Twenty patients (11 males, age 44.6 ± 15.1 years) with idiopathic right ventricular outflow tract (RVOT) PVCs (LBBB/inferior axis morphology with a negative QRS complex in lead aVL) successfully ablated from an endocardial site were also included in the study, and served as comparative controls. Six subjects with BrS phenotype (five during drug challenge) displayed PVCs with LBBB/inferior axis morphology and negative QRS complex in aVL lead which indicates an RVOT origin. The ECG characteristics of PVCs with LBBB/inferior axis in subjects with BrS and idiopathic RVOT arrhythmia were subsequently compared. QRS duration in inferior (p = 0.001) and right precordial leads (p < 0.001) was significantly longer in subjects with BrS phenotype. The RS interval in lead V2 was also significantly prolonged in individuals with BrS phenotype (p = 0.016). Subjects with BrS phenotype exhibited an increased intrinsicoid deflection time measured in right precordial leads compared to those with idiopathic RVOT PVCs (46.0 ± 7.6 vs. 27.2 ± 9.5 ms, p < 0.001). Finally, a pseudo-delta wave in precordial leads was more commonly observed in subjects with BrS ECG pattern (p = 0.029).

Conclusions

PVCs in BrS usually originate from the RVOT and display specific ECG characteristics that might be indicative of an epicardial origin. The prolonged interval criteria may be related to a localized epicardial conduction delay.     

Electrocardiographic determinants of the polymorphic QRS morphology in idiopathic right ventricular outflow tract tachycardia

Coupling Intervals and Polymorphic QRS Morphologies . Introduction: Premature ventricular contractions (PVCs) arising from the right ventricular outflow tract (RVOT) can trigger polymorphic ventricular tachycardia (PVT) or ventricular fibrillation (VF) in patients with no structural heart disease. We aimed to clarify the ECG determinants of the polymorphic QRS morphology in idiopathic RVOT PVT/VF. Methods and Results: The ECG parameters were compared between 18 patients with idiopathic PVT/VF (PVT‐group) and 21 with monomorphic VT arising from the RVOT (MVT‐group). The coupling interval (CI) of the first VT beat was comparable between the 2 groups. However, the prematurity index (PI) of the first VT beat was smaller in the PVT‐group than in the MVT‐group (P < 0.001). Furthermore, the QT index, defined as the ratio of the CI to the QT interval of the preceding sinus complex, was also smaller for the PVT/VF in the PVT‐group than that for the VT in the MVT‐group (P < 0.01). In the PVT‐group, the CI of the first VT beat was comparable between that of VT and isolated PVCs, but the PI of the first VT beat was shorter for VT than isolated PVCs (P < 0.05). The PI was the only independent determinant of the polymorphic QRS morphology (odd ratio = 2.198; 95% confidence interval = 1.321–3.659; P = 0.002). Conclusion: The smaller PIs of the first VT beat may result in a polymorphic QRS morphology. (Cardiovasc Electrophysiol, Vol. 23, pp. 521‐526, May 2012)