左束支起搏心电图的特点观察

目的通过比较自身心律、左束支起搏、右室心尖部或右室流出道起搏时心电图的形态和QRS波群时限等,找寻左束支起搏心电图的特征表现。方法选取拟行左束支起搏42例患者,记录标准12导联体表心电图,通过测量,分别比较自身心律、左束支起搏及右室心尖部/右室流出道起搏时QRS波群时限、电轴、形态及ST段的差异。结果自身心律与左束支起搏相比,QRS波群时限无统计学差异(P=0. 49),但与右室心尖部/右室流出道起搏相比,具有显著差异(P <0. 000)。左束支起搏组,V1导联呈特征性"M"或"r SR"的比例为76. 19%;a VR导联亦可呈特征性"M"或"r SR"表现,比例为78. 57%。对于自身心律为右束支阻滞者,左束支区域起搏仅V1导联呈"M"或"r SR",a VR导联呈QS型,而无特征性"M"或"r SR"表现。与经典的右束支阻滞心电图比较:左束支起搏ST段和T波改变无规律性。结论左束支起搏心电图QRS波群时限和电轴与自身心律相比无显著差别,V1及a VR导联均可见特征性"M"或"r SR"表现,右束支阻滞患者仅V1导联呈特征性表现,但依靠心电图的特征性"M"或"r SR"改变判断起搏位点有局限性。     

右心室心尖部起搏的心电图Ⅰ、aVL导联判断分析

通常认为右心室心尖部起搏体表心电图应呈左束支阻滞图形,但实际工作中右心室心尖部起搏患者体表心电图胸前导联呈典型左束支阻滞图形者只占约50%.本文通过分析我院85例植入WI或DDD起搏器患者术后体表12导联心电图,观察Ⅰ、aVL导联及胸前导联QRS波主波方向与形态,并与X线定位分析比较,以探寻一种判断右心室心尖部起搏更为简单、可靠的方法.     

第18课 罕见的束支传导阻滞

这份心电图(图1)是一例无症状、无器质性心脏病的52岁女性患者,该患者至门诊部是因常规心电图显示若干异常:①QRS电轴90°,②QRS时间0.14s,③肢体导联QRS形态提示束支传导阻滞,但仅根据这些尚难确定究竟是哪一种(右或左)束支传导阻滞。初看时,Ⅰ和aVL导联粗钝的S波提示右束支传导阻滞,而下壁导联的QRS形态(单相R波和继发性ST-T改变)较支持左束支传导阻滞伴电轴相对右偏。④胸导联(图形)使该问题更复杂化,因为V1导联(图形)提示右束支传导阻滞,而V5和V6导联呈单相R波完全与左束支传导阻滞相一致;此外,V5导联呈典型左束支传导阻滞时…     

VVI起搏致类右束支阻滞图形一例

一例 65岁女性 ,因高度房室阻滞而行VVI起搏治疗。术后胸片、超声心动图等检查示起搏电极头端位于右室近心尖部流入道。体表心电图示类右束支阻滞图形。术后检测起搏器感知、起搏功能正常。提示 ,正常右室心尖部或近心尖部起搏 ,可以出现类右束支阻滞图形心电图改变。     

左室乳头肌起源室性心律失常体表心电图特点及射频消融治疗

目的探讨起源于左室乳头肌室性心动过速/室性早搏(VT/PVCs)的体表心电图特点和导管射频消融术疗效。方法选取2010年5月~2014年8月在本院治疗的左室乳头肌起源VA患者6例,全部接受EPS+RFCA治疗,消融成功后结合消融靶点对患者体表心电图进行分析,同期选取另6例左后分支起源VA患者为对照组,对比分析两组患者体表心电图特点。结果 6例左室乳头肌VT/PVC组均消融成功,5例起源于左室后乳头肌的右束支阻滞图形胸导S波出现在V3导联以后,额面电轴左偏I AVL呈q R Rs q Rs R型主波向上II III AVF呈r S型主波向下,QRS宽大畸形平均时间(150±13)ms;1例起源于左室前乳头肌为右束支阻滞图形胸导S波出现在V3导联,额面电轴右偏I AVL呈r S型主波向下II呈RS型III呈R型AVF呈Rs型主波向上,QRS宽大畸形时间150 ms;对照组6例左后分支VT/PVC组均消融成功,心电图特点为右束支阻滞图形胸导S波逐渐加深,额面电轴左偏I AVL呈Rs RS R型主波向上II III AVF呈r S型主波向下,QRS时间(120±17)ms相对较窄。结论左室乳头肌起源VA体表心电图有其固有一定的特点,随着电生理技术不断发展,导管消融技术治疗这类心律失常被证实安全有效,即使这些患者合并结构性心脏病。     

心电图诊断能力大比武

征解6答案 房室沟左侧部位心外膜室速。诊断要点 本例心电图特征为规则的宽QRS波心动过速，心率155bpm。QRS波形态表现为右束支阻滞（V1导联QRS波直立，I和aVL导联明显倒置）。     

心电图诊断能力大比武(征解6:答案)

征解6答案房室沟左侧部位心外膜室速。诊断要点本例心电图特征为规则的宽QRS波心动过速,心率155bpm。QRS波形态表现为右束支阻滞(V1导联QRS波直立,I和aVL导联明显倒置)。     

左心室心尖部起搏的心电图Ⅰ、aVL导联判断分析

通常认为右心室心尖部起搏体表心电图应呈左束支阻滞图形,但实际工作中右心室心尖部起搏患者体表心电图胸前导联呈典型左束支阻滞图形者只占约５０％。本文通过分析我院８５例植入ＶＶＩ或ＤＤＤ起搏器患者术后体表１２导联心电图,观察Ⅰ、ａＶＬ导联及胸前导联ＱＲＳ波主波方向与形态,并与Ｘ线定位分析比较,以探寻一种判断右心室心尖部起搏更为简单、可靠的方法。 资料和方法１９９６年３月至２０００年１２月我院行心脏起搏器植入术患者８５例,４０例植入ＶＶＩ起搏器,４５例植入ＤＤＤ起搏器,均经Ｘ线后前位、右前斜位３０℃、左…     

重视起搏心电图分析

我国现年植入起搏器约3500台左右,为数虽不多,但累计病例逐年增加,已构成心电学诊断的新问题。心室起搏(VVI)电极放置于右室心尖,体表心电图呈左束支阻滞图形,电轴左偏。因此在起搏心电图上甚难识别心肌梗塞、心室肥大、供血不足,对此诊断有赖于病吏、心肌酶学、超声心动图和心肌核素显像。起搏心电图显示清晰脉冲十分重要,单极起搏者脉冲信号大,双极起搏者脉冲信号小,通常在心电图Ⅱ导联最为清楚。     

超声心动图引导下安置起搏器一例

<正> 患者男性,30岁,因阵发性心悸,乏力伴反复发作头昏、黑矇2年入院。诊断病态窦房结综合征。于1991年1月4日在TOSHIBA SSH-160彩色多普勒超声心动图的引导下安置起搏器。经左头静脉插入心内膜起搏电极导管(CPI 4150—031530),以二维超声心动图心尖四腔观及肋下四腔观进行引导,清楚显示出电极导管由右房经三尖瓣口进入右室心尖部,遂将起搏电极导管置入右室心尖近室间隔部,心腔内心电图呈rS型,ST段抬高6mV。测起搏阈值为0.8V,心肌阻抗775Ω,体表心电图示电轴左偏—77°,QRS波呈完全性左束支阻滞图形。令患者咳嗽、翻身均无变化,便于左上胸壁埋入CPI公司Astra T_(?)型起搏器,起搏良好。三日后起床活动。出院前胸片示起搏电极位置及心腔内弧度适度,无扭曲、打弯现象。     

Safe right bundle branch block pattern during permanent right ventricular pacing

It is known that an electrocardiogram (ECG) after transvenous right ventricular (RV) pacing should yield left bundle branch block (LBBB) QRS patterns. When right bundle branch block (RBBB) pacing morphology appears in a patient with a permanent or temporary transvenous RV pacemaker, myocardial perforation or malposition of the pacing lead must be ruled out, even though the patient may be asymptomatic. We report a case of a 77-year-old man who underwent permanent transvenous VDD pacemaker implantation for symptomatic heart block. The postoperative ECG revealed a RBBB pacing configuration, but his chest X-ray and echocardiographic studies confirmed uncomplicated RV pacing. We review and discuss the literature concerning the differential diagnosis of such a safe RBBB ECG pattern.     

An electrocardiographic algorithm for determining the location of pacemaker electrode in patients with right bundle branch block configuration during permanent ventricular pacing

The expected morphology of right ventricular pacing is a left bundle branch block (LBBB) pattern. However, right bundle branch block (RBBB) can also be seen during permanent right ventricular pacing. The aim of this study was to develop an electrocardiographic algorithm to differentiate this benign condition from septal and free wall perforation with subsequent left ventricular pacing. Three hundred consecutive patients who had permanent ventricular or dual-chamber pacemaker implantation between 1999 and 2000 were screened and 25 patients (8.3%) who exhibited RBBB configuration were included in the study. Echocardiograms and chest radiographs were evaluated in order to identify the pacing lead location in this group. The authors formed a study group with their own 25 patients and 22 cases of RBBB with permanent pacemaker from previous publications (total 47 patients). Frontal axis, QRS morphology in lead V(1), and the precordial transition point, which is defined as the precordial lead where R wave amplitude is equal to S wave amplitude, were examined. Placement of precordial leads V(1) and V(2) 1 interspace lower than the standard location (Klein maneuver) eliminated the RBBB pattern in 12 patients. RBBB pattern with "true right ventricular pacing" was detected in 24 of the 25 patients, and in 11 of the 22 patients reported in the literature (total 35 patients). Right ventricular pacing was correctly identified in 34 of 35 patients with use of criteria including left superior axis deviation, RS or qR morphology in lead V(1), and precordial transition at lead V(3) with a high sensitivity and specificity. A simple surface electrocardiogram can accurately predict the lead location in patients having RBBB morphology with right ventricular pacing.     

心室再同步化起搏的心电图表现及随访

目的探讨不同心室起搏部位体表十二导联心电图的变化及在双心室再同步起搏(CRT)随访中的应用。方法22例资料完整的充血性心力衰竭患者进行双心室再同步起搏治疗,其中21例经静脉置入左室导线,1例因冠状静脉窦畸形经胸左室外膜导线置入;右室导线均放置在心尖部。22例分别记录无起搏、右室起搏、左室起搏及双心室同步起搏四种不同状态下的十二导联心电图。结果22例术前心电图显示完全性左束支传导阻滞(CLBBB)16例,完全性心室内传导阻滞6例,行右室心尖部起搏时胸前导联(V1)均呈CLBBB型,肢体导联额面电轴左偏,Ⅰ导联呈r、R型占100%,左室起搏时胸前导联(V1)均呈右束支传导阻滞(CRBBB)型,额面电轴右偏,Ⅰ导联呈q、Q、QS型20例,占91%;双心室同步起搏后胸前导联(V1)呈CLBBB型13例,呈CRBBB型9例,额面电轴均右偏,Ⅰ导联呈q、Q、QS型占86.5%。结论不同部位心室起搏具有不同的心电图表现,双心室同步起搏具有特征性的心电图形态,CRT随访时通过对心电图形态和时限的观察有助于判断是否实现真正有效的双心室再同步起搏。     

Clinical features of emergency electrocardiography in patients with acute myocardial infarction caused by left main trunk obstruction.

BACKGROUND: To diagnose left main trunk (LMT) infarction by 12-lead standard electrocardiogram (ECG) is an important emergency technique, but the features in LMT infarctions have not been clarified. METHODS AND RESULTS: The study enrolled 140 subjects who were divided into 4 groups according to the location of the culprit artery: 35 with LMT, 35 with left anterior descending artery (LAD), 35 with right coronary artery and 35 with left circumflex artery. Various parameters obtained from the ECGs were analyzed. Average QTc interval (0.51 +/- 0.06 s) in LMT group was markedly longer than that in the 3 other groups. Average QRS axis (-10 +/- 77 degrees) in LMT infarction showed a remarkable left deviation. ST-segment elevation in lead aVR occurred in 28 patients (80.0%) in the LMT group. The ECG features of the LMT group could be classified into 2 main groups: right bundle branch block (RBBB) with a marked left axis deviation (RBBB + LADEV type) and ST-segment elevation in leads V2-5, I and aVL without abnormal axis deviation (LAD type). CONCLUSION: Either ST-segment elevation in lead aVR and marked prolongation of both the QRS width and QTc interval with a prominent abnormal axis deviation or ST-segment elevation in the broad anterior precordial lead with a normal QRS axis strongly suggests LMT infarction.     

Electrocardiographic characteristics of repetitive monomorphic right ventricular tachycardia originating near the His-bundle

INTRODUCTION: Most idiopathic nonreentrant ventricular tachycardia (VT) and ventricular premature contractions (VPCs) arise from the right or left ventricular outflow tract (OT). However, some right ventricular (RV) VT/VPCs originate near the His-bundle region. The aim of this study was to investigate ECG characteristics of VT/VPCs originating near the His-bundle in comparison with right ventricular outflow tract (RVOT)-VT/VPCs. METHODS AND RESULTS: Ninety RV-VT/VPC patients underwent catheter mapping and radiofrequency ablation. ECG variables were compared between VT/VPCs originating from the RVOT and near the His-bundle. Ten patients had foci near the His-bundle (HIS group), with the His-bundle local ventricular electrogram preceding the QRS onset by 15-35 msec (mean: 22 msec) and His-bundle pacing produced a nearly identical ECG to clinical VT/VPCs. The HIS group R wave amplitude in the inferior leads (lead III: 1.0 +/- 0.6 mV) was significantly lower than that of the RVOT group (1.7 +/- 0.4 mV, P < 0.05). An R wave in aVL was present in 6 of 10 HIS group patients, while almost all RVOT group patients had a QS pattern in aVL. Lead I in HIS group exhibited significantly taller R wave amplitudes than RVOT group. HIS group QRS duration in the inferior leads was shorter than that of the RVOT group. Eight of 10 HIS group patients exhibited a QS pattern in lead V1 compared to 14 of 81 RVOT group patients. HIS group had larger R wave amplitudes in leads V5 and V6 than RVOT group. CONCLUSION: VT/VPCs originating near the His-bundle have distinctive ECG characteristics. Knowledge of the characteristic QRS morphology may facilitate catheter mapping and successful ablation.     

Electrocardiographic predictors of validated right ventricular outflow tract septal pacing for correct localization of transthoracic echocardiography

Background

Electrocardiographic (ECG) characteristics of true right ventricular outflow tract (RVOT) septal pacing have not been clearly demonstrated.

Hypothesis

We hypothesized that ECG parameters would help operators differentiate true RVOT septum from non‐septal septum.

Methods

We analyzed 151 patients who underwent pacemaker implantation with a ventricular lead in the RVOT. Transthoracic echocardiographic (TTE) determination of pacing sites was applied in all patients after implantation. A 12‐lead ECG was recorded during forced ventricular pacing.

Results

According to TTE orientation, pacing at the RVOT septum was achieved in 94 patients (62.3%). Compared with nonseptal pacing, septal pacing had significantly shorter QRS duration (139.2 ± 18.5 ms vs 155.5 ± 14.7 ms; P < 0.001). More frequent negative or isoelectric QRS vector in lead I (76% vs 32%; P < 0.001), lead II/III R‐wave amplitude ratio < 1 (52% vs 25%; P = 0.001), and aVR/aVL QS‐wave amplitude ratio < 1 (59% vs 32%; P = 0.001) were observed in septal pacing. Transitional zone (TZ) score (3.8 ± 0.96 vs 4.2 ± 0.90; P = 0.004) and TZ index (0.3 ± 0.5 vs 0.6 ± 0.7; P = 0.008) were significantly lower in septal pacing than in nonseptal pacing, respectively. In multivariate analysis, paced QRS duration and negative or isoelectric QRS vector in lead I independently predicted RVOT septal pacing (P < 0.001). At ROC curve analysis, paced QRS duration ≤145 ms identified RVOT septal pacing with 85.1% sensitivity and 78.9% specificity.

Conclusions

This study reveals the heterogeneity of lead placement within the RVOT. Narrower paced QRS duration and negative or isoelectric QRS vector in lead I independently predict RVOT septal pacing.     

An unusual bundle-branch block

We report a case of right bundle-branch block (RBBB) showing a QRS configuration typical for left bundle-branch block (LBBB) in leads V(5) and V(6). The QRS axis was at +90 degrees, and the QRS duration was 0.14 second. There were wide S waves in leads I and aVL, suggesting at first glance an RBBB, but the QRS morphology in the inferior leads (monophasic R wave with secondary ST-T changes) was more consistent with an LBBB. Lead V(1) suggested an RBBB, whereas leads V(5) and V(6) showed a monophasic R wave as in LBBB; moreover, a negative T wave, typical of LBBB, was present in lead V(5). Placement of the electrodes of leads V(4), V(5), and V(6) 2 intercostal spaces above restored in these leads a QRS configuration suggestive of RBBB. The diagnostic problem was mainly caused by the inferior direction of the QRS axis. Because the electrode of V(6) is normally placed below the electrical center of the heart, namely, on a plane that is not orthogonal to the sagittal plane, a vector directed mainly inferiorly and slightly to the right does not project on the negative part but on the positive of the lead line. For this reason, the S waves normally observed in the left precordial leads with RBBB disappear. The superior displacement of the electrodes "normalizes" the plane upon which the lead lines lie, thereby restoring the expected QRS configuration.     

Differentiating arrhythmogenic right ventricular cardiomyopathy from right ventricular outflow tract ventricular tachycardia using multilead QRS duration and axis.

BACKGROUND: Ventricular tachycardia (VT) resulting from arrhythmogenic right ventricular cardiomyopathy (ARVC) may be difficult to differentiate from idiopathic right ventricular outflow tract (RVOT) VT. OBJECTIVES: The purpose of this study was to investigate the hypothesis that QRS characteristics would be different in ARVC because of altered conduction through abnormal myocardium. METHODS: In 24 RVOT VT patients (18 women and 6 men; age 42 +/- 10 years) and 20 ARVC patients (12 women and 8 men; age 38 +/- 14 years), mean QRS duration, frontal plane axis, and precordial R-wave transition were measured in 12-lead ECGs recorded during VT. RESULTS: Mean QRS duration was longer in all 12 leads in ARVC patients. A significant difference was noted in leads I, III, aVL, aVF, V(1), V(2), and V(3) (P <.05). Leads I and aVL had the largest mean difference between ARVC and RVOT VT patients of 17.6 +/- 4.7 ms and 15.8 +/- 7.5 ms, respectively (P <.0001). Lead I QRS duration > or =120 ms had a sensitivity of 100%, specificity 46%, positive predictive value 61%, and negative predictive value 100% for ARVC. The area under the receiver operating characteristic (ROC) curve was 0.89. The addition of mean QRS axis <30 degrees (R相似文献   

Effect of Right Bundle Branch Block on Electrocardiographic Amplitudes,Including Combined Voltage Criteria Used for the Detection of Left Ventricular Hypertrophy

Background: Although right bundle branch block (RBBB) delays right ventricular depolarization, its effect on cancellation of right and left ventricular forces within the QRS complex has not been quantified during stable temporal and physiological conditions. Systematic changes in QRS amplitude during transient RBBB bear directly on performance of standard ECG criteria for left ventricular hypertrophy (LVH), and these changes require quantification. Methods: We examined the instantaneous effect of RBBB on QRS amplitudes and LVH voltages in 40 patients who had intermittent complete RBBB during a single 10 sec standard 12‐lead ECG recording, comprising 0.1% of approximately 400,000 consecutive ECGs in a university teaching hospital setting. Amplitudes were measured by magnifying graticule to the nearest 25 microvolts, averaged for up to 3 normal and 3 RBBB complexes, and compared by paired t test. Results: RBBB was associated with an increase in initial QRS forces (RV1, RV2, and QV6) but significant decreases in mean mid‐QRS amplitudes that reflect left ventricular depolarization (RaVL [−75 microvolts], SV1 [−389 microvolts], SV3 [−617 microvolts], RV5 [−100 microvolts], and RV6 [−123 microvolts]). All late QRS forces were increased with RBBB (R'V1, SV5, SI). As a result, combined voltages used for LVH criteria were significantly reduced by RBBB: Sokolow‐Lyon voltage decreased from 1520 ± 739 to 1014 ± 512 microvolts (p < 0.001) , and Cornell voltage decreased from 1438 ± 683 to 746 ± 399 microvolts (p < 0.001) . Conclusions: RBBB is associated with significant reduction in "left ventricular" QRS amplitudes of the standard ECG, consistent with cancellation, rather than unmasking, of left ventricular mid‐QRS forces by altered septal and delayed right ventricular depolarization. Because QRS voltages that are routinely combined for the detection of LVH are reduced in RBBB, standard LVH criteria will perform with lower sensitivity in patients with RBBB.