形态心电图标准在原有束支阻滞伴宽QRS波群心动过速鉴别诊断中的特异性评价

为探讨形态心电图标准是否适用原有束支阻滞（ＢＢＢ）或心肌梗塞患者合并宽ＱＲＳ波群心动过速的鉴别诊断,选择窦性心律呈ＢＢＢ的患者２０５例［左束支阻滞（ＬＢＢＢ）４５例、右束支阻带（ＲＢＢＢ）１６０例］,分析形态心电图标准用于鉴别宽ＱＲＳ波群心动过速的特异性。胸导联ＱＲＳ波群图形一致、胸导联无ＲＳ型;ＲＢＢＢ时任一胸导联ＲＳ时限＞１００ｍｓ,Ｖ１导联单向（Ｒ）或双向（ｑＲ、ＱＲ、ＲＳ）、呈左兔耳征,Ｖ６导联或ａＶＦ导联Ｑ波,Ｖ６导联Ｒ／Ｓ＜１;ＬＢＢＢ时,Ｖ１、Ｖ２导联ｒ波时限＞３０ｍｓ,Ｖ１、Ｖ２导联Ｓ波降支钝挫,Ｖ６导联或ａＶＦ导联ｑ（Ｑ）波等１２条特异性较高。ＱＲＳ波群时限＞１４０ｍｓ;ＲＢＢＢ时电轴重度左、右偏,ａＶＦ导联Ｒ／Ｓ＜１;ＬＢＢＢ时Ｖ１、Ｖ２导联ＲＳ时限＞６０ｍｓ,Ⅰ导联负向ＱＲＳ波群,Ｖ４较Ｖ１导联Ｓ波振幅更深等７条特异性较低。心肌梗死合并宽ＱＲＳ波群心动过速时采用上述标准鉴别诊断有一定局限。     

The differential diagnosis on the electrocardiogram between ventricular tachycardia and preexcited tachycardia

The 12-lead surface electrocardiogram is a simple and useful tool for the differential diagnosis of regular wide QRS complex tachycardia. However, criteria do not as yet exist to discriminate between ventricular tachycardia and supraventricular tachycardia with anterograde conduction over an accessory pathway (preexcited tachycardia). Therefore, we designed a new stepwise approach with three criteria for the electrocardiographic differential diagnosis between ventricular tachycardia and preexcited tachycardia and prospectively studied 267 regular tachycardias with electrophysiologically proven mechanism and a wide QRS complex (≥ 0.12 s): 149 consecutive ventricular tachycardias and 118 consecutive preexcited regular tachycardias. Underlying heart disease was old myocardial infarction in 133 of 149 (89%) ventricular tachycardias. The patients presenting with preexcited tachycardia had no additional structural heart disease. Atrial fibrillation with preexcited QRS complex was not included. The criteria favoring ventricular tachycardia were: (1) presence of predominantly negative QRS complexes in the precordial leads V₄ to V₆, (2) presence of a QR complex in one or more of the precordial leads V₂ to V₆, and (3) AV relation different from 1:1 (more QRS complexes than P waves). The final sensitivity and specificity of these three consecutive steps to diagnose ventricular tachycardia were 0.75 and 1.00, respectively. This new stepwise approach is sensitive and highly specific for the differential diagnosis between ventricular tachycardia in coronary artery disease and preexcited regular tachycardia.     

起源于主动脉窦频发室性期前收缩的心电生理特征及射频消融治疗

目的报道11例起源于主动脉窦的频发室性期前收缩（premature ventricular contraction,PVC）患者的心电生理特征、射频消融（radiofrequency catheter ablation,RFCA）方法及疗效。方法分析患者术前体表心电图和动态心电图PVC的特点,测量V1或V2导联r波时限和振幅,计算r波与QRS波时限的比值及r波于S波振幅的比值。术中行主动脉窦内激动标测和起搏标测确定PVC起源部位,并行冠状动脉造影辅助定位后行RFCA。结果11例均有频发PVC,5例有反复短阵室性心动过速。下壁导联QRS波呈R形且高大直立,V1导联呈rS型,胸前导联多移行于V3以前,V6导联多呈Rs型或无S波。V1导联r波时限（84.6±9.8）ms,占QRS波时限的50%以上;r/S振幅比值0.72±0.31。有效消融靶点局部电图V波较体表心电图的QRS波明显提前（35.6±8.9）ms,有效靶点放电2～8 s见PVC减少至消失。结论起源于主动脉窦的PVC其下壁导联QRS波呈R形且高大直立,V1或V2导联r波时限宽（〉50%同导联QRS波）,r波振幅高（〉30%同导联S波）;主动脉窦内PVC的射频消融治疗是安全、有效的。     

Surface electrocardiographic clues suggesting presence of a nodofascicular Mahaim fiber

Standard electrocardiograms from 87 consecutive patients with tachycardia of left bundle branch block configuration were analyzed retrospectively for features that might be characteristic of tachycardia utilizing a nodofascicular Mahaim fiber. The study group consisted of 13 patients with nodofascicular tachycardia, 34 with supraventricular tachycardia and aberrant conduction over the His-Purkinje system, 22 with ventricular tachycardia and 18 with antidromic tachycardia utilizing a right-sided accessory atrioventricular pathway. Six variables present during tachycardia of left bundle branch block configuration were predictive of a nodofascicular fiber: cycle length between 220 and 450 ms, QRS axis of 0 to -75 degrees, QRS duration 0.15 second or less, R wave in lead I, rS wave in precordial lead V1 and a precordial transition from a negative to a positive QRS complex after lead V4. All six criteria were present in 16 of the 87 patients. No patient with ventricular tachycardia satisfied these criteria, whereas 3 of 34 with supraventricular tachycardia, 1 of 18 with antidromic tachycardia and 12 of 13 with tachycardia using a nodofascicular fiber did. It is concluded that analysis of the surface electrocardiogram during tachycardia may suggest the presence of a nodofascicular fiber.     

A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex

BACKGROUND. In the differential diagnosis of a tachycardia with a wide QRS complex (greater than or equal to 0.12 second) diagnostic mistakes are frequent. Therefore, we investigated the reasons for failure of presently available criteria, and we identified new, simpler criteria and incorporated them in a stepwise approach that provides better sensitivity and specificity for making a correct diagnosis. METHODS AND RESULTS. A prospective analysis revealed that current criteria had a poor specificity for the differential diagnosis. The value of four new criteria incorporated in a stepwise approach was prospectively analyzed in a total of 554 tachycardias with a widened QRS complex (384 ventricular and 170 supraventricular). The sensitivity of the four consecutive steps was 0.987, and the specificity was 0.965. CONCLUSIONS. Current criteria for the differential diagnosis between supraventricular tachycardia with aberrant conduction and ventricular tachycardia are frequently absent or suggest the wrong diagnosis. The absence of an RS complex in all precordial leads is easily recognizable and highly specific for the diagnosis of ventricular tachycardia. When an RS complex is present in one or more precordial leads, an RS interval of more than 100 msec is highly specific for ventricular tachycardia. This new stepwise approach may prevent diagnostic mistakes.     

Comparison of a vectorcardiographically derived 12-lead electrocardiogram with the conventional electrocardiogram during wide QRS complex tachycardia, and its potential application for continuous bedside monitoring.

Previous investigators published conflicting reports comparing a vectorcardiographically derived electrocardiogram (ECGD) with the conventional 12-lead one (ECG). Prior comparisons were obtained in adults during sinus rhythm, but never in patients with wide QRS complex tachycardia. The ECGD was evaluated during baseline rhythms in patients with varying cardiac diagnoses, and the diagnostic accuracy of the 2 methods was compared during 64 episodes of wide QRS complex tachycardia in 49 patients during cardiac electrophysiologic study. All leads of the 12-lead ECGD closely resembled the conventional ECG in baseline and tachycardia tracings, except leads V3 and V4. QRS voltages were less in the ECGD, resulting in an inability to detect left ventricular hypertrophy in one third of patients with that diagnosis. There was excellent agreement between the ECGD and ECG in diagnosing prior myocardial infarction (92%), ventricular preexcitation patterns (100%), bundle branch and fascicular blocks (100%), and axis deviation. The ECGD was equally as valuable as the ECG in the diagnosis of wide QRS complex tachycardia. There was perfect agreement between the 2 lead systems in application of the morphologic criteria differentiating supraventricular tachycardia with aberration from ventricular tachycardia in leads V1, V2 and V6, and for criteria requiring axis determination and measurement of RS intervals in the precordial leads. The ECGD tracings contained less muscle artifact during body movements (e.g., after direct-current defibrillation). In conclusion, the ECGD's close correlation with the ECG, and its technical superiority and simple 5 torso-positioned electrode configuration make it worth pursuing as an option for continuous bedside monitoring.     

QRS Complex Voltage Changes Associated with Supraventricular Tachycardia

INTRODUCTION: The aim of this study was to evaluate the changes in ventricular complex voltage associated with narrow QRS supraventricular tachycardia (SVT). METHODS AND RESULTS: One hundred forty-five patients undergoing catheter ablation for SVT, 85 with AV nodal reentrant tachycardia (AVNRT) and 60 with AV reentrant tachycardia (AVRT) due to a concealed accessory pathway, were studied. Four consecutive tachycardia beats and four consecutive sinus beats were analyzed, excluding the last tachycardia complex and the first sinus one. For each of the 12 leads, the QRS complex voltage was measured, and the results of four beats were averaged both in SVT and in sinus rhythm (SR). The sum (sigma) of the QRS voltages measured in the 12 leads during SVT (sigmaSVT) and SR (sigmaSR) were calculated, as well as the QRS axis during SVT and SR. QRS complex voltage was significantly increased during SVT, with respect to SR, in leads II, III, aVR, aVF, and V2 to V6. In addition, sigmaSVT was significantly greater than sigmaSR. Only lead V1 showed a significant voltage decrease during SVT. These voltage changes were almost identical in patients with AVNRT and patients with AVRT. No relationship was found between tachycardia rate and QRS voltage variation. The QRS axis showed a significant shift during SVT, from 55.8 degrees to 64.5 degrees. CONCLUSION: QRS voltage increase occurs in reentrant SVT, independent of the underlying reentrant circuit. The phenomenon likely depends on tachycardia-related reduced ventricular filling. This could result in displacement of the heart in such a way that the left ventricle becomes closer to the precordial electrodes (proximity effect). Alternatively, decreased intracavitary blood mass could diminish the intracardiac short-circuiting of potentials, resulting in augmented transmission of cardiac vectors to the body surface.     

Accuracy of bedside electrocardiographic monitoring: a report on current practices of critical care nurses

Diagnostic criteria for many arrhythmias can be observed from any monitoring lead; however, other important criteria are "lead specific," such as the diagnostic QRS patterns in V1 that aid in distinguishing ventricular tachycardia from supraventricular tachycardia with bundle branch block or aberration. Therefore, it makes a great deal of difference which leads are selected for bedside monitoring. Our purpose was to determine which leads nurses select for monitoring, and the accuracy of lead placement. From a random sample of nurses who were members of the American Association of Critical-Care Nurses, 302 returned a monitoring questionnaire. Average critical care experience was 8.5 years. Lead II was most often selected (74%) for single-channel monitoring; lead II plus V1 (or MCL1) were most often selected (87%) for dual-channel monitoring. Only 37% of nurses demonstrated proper technique for obtaining their single lead of choice; even fewer (13%) demonstrated proper technique for obtaining their dual leads of choice. These results suggest that misdiagnosis of arrhythmias such a wide complex tachycardia in monitored patients may be caused by inappropriate lead selection as well as inaccurate lead placement.     

A transcardiac lead system for identification and termination of supraventricular and ventricular tachycardia

The value of a transcardiac lead system (coronary sinus to right ventricular apex) to record atrial and ventricular electrical activity and its pacing capabilities was assessed in 20 patients with a variety of tachycardias (atrial tachycardia in 3 patients, atrial flutter in 4, intranodal tachycardia in 6, circus movement tachycardia using an accessory pathway in 1 patient, and ventricular tachycardia in 9). The transcardiac lead invariably showed both atrial and ventricular electrical activity during sinus rhythm and tachycardias, allowing application of the same criteria as used when analyzing cardiac rhythm on the surface electrocardiogram. Atrial complexes had a mean amplitude of 4.2 mV during sinus rhythm and varied from 3.0 to 4.1 mV during the different types of tachycardia. Ventricular complexes had a mean amplitude of 9.8 mV during sinus rhythm, 13.8 mV during supraventricular tachycardia and 16.1 mV during ventricular tachycardia. The duration of the QRS complex on the transcardiac lead was equal to the duration of the QRS complex on the surface electrocardiogram during tachycardias with a small or wide QRS complex. By varying the intensity of current delivered through the transcardiac lead, only right ventricular pacing (mean current intensity 1.2 +/- 0.4 mA) or simultaneous atrioventricular pacing (mean current intensity 4.7 +/- 3.3 mA) could be achieved. Termination of all episodes of tachycardia was achieved with either ventricular pacing or simultaneous atrioventricular pacing. This transcardiac lead system allows clear identification of atrial and ventricular events, is suitable for tachycardia analysis using simple surface electrocardiographic algorithms and allows pacing termination of a variety of tachycardias.     

无人区心电轴在宽QRS波心动过速中的鉴别诊断价值

目的探讨无人区心电轴在宽QRS波心动过速(WCT)中的鉴别诊断价值。方法收集并测量北京大学人民医院2000年1月至2005年10月经心内电生理检查明确诊断的WCT患者窦性心律及心动过速时心电图中Ⅰ、Ⅲ标准导联QRS波振幅的代数和,计算QRS波额面平均心电轴,观察无人区心电轴出现的心律失常类型及规律。结果137例[其中特发性室性心动过速(IVT)65例,室上性心动过速(室上速,SVT)72例]明确诊断的WCT患者中,18例出现无人区心电轴,其中室性心动过速(室速)16例(占室速24.6%,占总病例11.7%),均为左心室特发性室速;宽QRS波室上速2例(占宽QRS波室上速2.8%,占总病例1.5%),均为心房颤动(房颤)伴左侧旁路前传。结论无人区心电轴可以作为鉴别室速与宽QRS波室上速的一项可靠指标。     

Lesson Thirty-two New Algorithm Using Only Lead aVR for Differential Diagnosis of Wide QRS Complex Tachycardia

Making an accurate rapid diagnosis in patients with wide QRS complex tachycardia remains a signifi-cant clinical problem1. We recently proposed a new simplified four-step decision treelike algorithm to dis-tinguish between regular monomorphic wide QRS com-plex tachycardias caused by supraventricular ventricular tachycardia (SVT) and ventricular tachycardia (VT).……     

Electrical alternans in wide complex tachycardias

The occurrence of electrical alternation of 0.1 mV or greater of the QRS or T wave was analyzed in 156 electrocardiograms that showed wide QRS complex tachycardias from 91 patients. One hundred thirty-six ventricular tachycardias (VT) were recorded from 74 patients and 20 supraventricular tachycardias (SVT) from 17 patients. Alternans was present in 42 tracings (27%) from 35 patients (38%) and was equally frequent in the patients with VT (39%) and those with SVT (35%). Alternans occurred in 36 VTs (27%) and 6 SVTs (30%). Tachycardias with alternans had a shorter mean cycle length than tachycardias without alternans (339 +/- 53 vs 368 +/- 85 ms, p less than 0.05), but were not associated with a particular QRS morphology or axis. Alternans was most frequent in leads V2 and V3 and was seen in more leads during SVT than VT (7.2 +/- 2.6 vs 3.7 +/- 2.5, p less than 0.005). All SVTs with alternans incorporated an atrioventricular bypass tract. Electrical alternans occurs frequently in wide QRS tachycardias. Alone, it does not help differentiate VT from SVT. SVTs utilizing bypass tracts frequently show alternans even if the QRS is wide, and this finding may be useful in determining the mechanism of SVTs with aberrant intraventricular conduction.     

Electrocardiographic criteria for ventricular tachycardia in wide complex left bundle branch block morphology tachycardias

Four electrocardiographic criteria for ventricular tachycardia (VT) were proposed and evaluated. These included (1) an R wave in V1 or V2 of greater than 30-ms duration; (2) any Q wave in V6; (3) a duration of greater than 60 ms from the onset of the QRS to the nadir of the S wave in V1 or V2 and (4) notching on the downstroke of the S wave in V1 or V2. The data showed that all 4 criteria had high predictive accuracy (96 to 100%) and specificity (94 to 100%). The relatively low sensitivities of the 4 criteria alone (30 to 64%) might limit their efficacy. Grouped criteria, however, could differentiate VT from supraventricular tachycardias with high sensitivity, specificity and predictive accuracy. The amount of tracings having either electrocardiographic criteria (1) or (2) or (3) or (4) was determined. The proposed combined criteria had a sensitivity of 100%, specificity of 89% and a predictive accuracy of 96%. Left axis deviation alone was of no value in distinguishing VT from supraventricular tachycardia. Characteristic patterns were present for left bundle branch block pattern VT associated with anterior and inferior myocardial infarction. In conclusion, the 12-lead electrocardiogram alone, when systematically analyzed, can be used to accurately diagnose the origin of wide complex tachycardias with left bundle branch block pattern. Attention to these criteria may lead to more rapid and effective therapy.     

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   

Multivariate analysis to simplify the differential diagnosis of broad complex tachycardia.

Univariate analysis has identified several criteria that aid the differential diagnosis of broad complex tachycardia. In this study of 102 consecutive patients multivariate analysis was performed to identify which of 15 clinical and 11 electrocardiographic variables were independent predictors of ventricular tachycardia. These were shown to be a history of myocardial infarction, the QRS waveforms in leads aVF and V1, and a change in axis from sinus rhythm to tachycardia of more than 40 degrees. If none of the criteria was met, the diagnosis was almost certainly supraventricular tachycardia. If one criterion was met the diagnosis was probably supraventricular tachycardia. If two criteria were met then the diagnosis was probably ventricular tachycardia. If three or four criteria were met, the diagnosis was almost certainly ventricular tachycardia. The predictive accuracy was 93%. This was increased to 95% by including two other criteria--definite independent P wave activity and ventricular extrasystoles with the same QRS configuration as that in tachycardia. These criteria were not included in the multivariate analysis because though they were 100% specific they were seldom seen. These four criteria can be used as simple rules in determining the origin of a broad complex tachycardia.     

36例致心律失常性右室心肌病的心电图特征和临床观察

目的探讨致心律失常性右室心肌病(ARVC)的心电图特征和临床表现。方法回顾分析符合欧洲心脏病协会ARVC诊断标准的36例患者的心电图参数、临床表现、超声心动图、腔内电生理检查等临床资料。结果36例中男26例、女10例,年龄37±13岁;33例表现为心悸、胸闷,11例同时伴有晕厥,2例有家族性猝死史。心电图研究发现10例(28%)出现Epsilon波,29例(81%)右胸(V1～V3)导联QRS波时限≥110ms;在29例无右束支传导阻滞的患者中,右胸导联分别有16例(55%)出现T波倒置、18例(62%)出现S波升支时间≥55ms;17例(47%)QRSd1/QRSd2(V1～V3导联与V4～V6导联QRS波时间平均值之比)≥1.2;24例(67%)出现室壁阻滞;27例(75%)记录到持续性或非持续性室性心动过速。29例超声心动图表现为严重的右室受累。25例行腔内电生理检查,20例诱发出右室起源的室性心动过速,即刻射频消融成功11例。结论ARVC好发于青年男性,是引起晕厥、室性心律失常和室壁运动异常的重要原因,Epsilon波、右胸导联QRS波时限≥110ms与T波倒置、右室起源的室性心律失常为其特征性的心电图改变,QRSd1/QRSd2≥1.2、室壁阻滞、右胸导联S波升支时间≥55ms有助于该病的诊断,经导管射频消融治疗室性心动过速成功率低。     

Multivariate analysis to simplify the differential diagnosis of broad complex tachycardia

Univariate analysis has identified several criteria that aid the differential diagnosis of broad complex tachycardia. In this study of 102 consecutive patients multivariate analysis was performed to identify which of 15 clinical and 11 electrocardiographic variables were independent predictors of ventricular tachycardia. These were shown to be a history of myocardial infarction, the QRS waveforms in leads aVF and V1, and a change in axis from sinus rhythm to tachycardia of more than 40 degrees. If none of the criteria was met, the diagnosis was almost certainly supraventricular tachycardia. If one criterion was met the diagnosis was probably supraventricular tachycardia. If two criteria were met then the diagnosis was probably ventricular tachycardia. If three or four criteria were met, the diagnosis was almost certainly ventricular tachycardia. The predictive accuracy was 93%. This was increased to 95% by including two other criteria--definite independent P wave activity and ventricular extrasystoles with the same QRS configuration as that in tachycardia. These criteria were not included in the multivariate analysis because though they were 100% specific they were seldom seen. These four criteria can be used as simple rules in determining the origin of a broad complex tachycardia.     

The value of the 12-lead ECG for evaluation and optimization of cardiac resynchronization therapy in daily clinical practice

Based on existing literature and some new data we propose a simple three-step strategy using the standard 12-lead ECG for patient selection and optimal delivery of cardiac resynchronization therapy (CRT). (1) Complete LBBB with regard to the indication for CRT can probably best be identified by a QRS duration of ≥ 130 ms for women and ≥ 120 ms for men with the presence of mid-QRS notch-/slurring in ≥ 2 contiguous leads of V₁, V₂, V₅, V₆, I and aVL. (2) Left ventricular (LV) free wall pacing should result in a positive QRS complex in lead V₁, with estimation of the exact LV lead position in the circumferential and apico-basal direction using lead aVF and the precordial leads, respectively. Wide and fractionated LV-paced QRS complexes may indicate pacing in scar tissue. (3) Atrioventricular and interventricular stimulation intervals may be optimized by adjusting them until precordial leads show fusion patterns between left and right ventricular activation wavefronts in the QRS complex.     

Useful clinical criteria for the diagnosis of ventricular tachycardia

Misdiagnosis occurs upon initial presentation to medical attention in a considerable number of patients referred for evaluation of wide QRS tachycardia. In order to improve diagnostic accuracy (ventricular versus supraventricular tachycardia), the answers to two key bedside questions were prospectively evaluated: (1) Had the patient experienced a prior myocardial infarction? (2) Did symptoms of tachyarrhythmia start only after the infarction? A patient presenting with a wide QRS tachycardia was considered to have ventricular tachycardia if he or she answered in the affirmative to both of these questions. Of 31 consecutive patients referred with electrocardiographically documented sustained wide QRS tachycardia that was reproduced in the electrophysiology laboratory, the diagnoses made when the patients first presented to medical attention were ventricular tachycardias in 17 patients and supraventricular tachycardias in 14 patients. Following electrophysiologic evaluation, 29 were diagnosed as having ventricular tachycardia and two as supraventricular tachycardia. If the diagnoses were made solely on the basis of responses to the bedside questions mentioned earlier, 28 of the 29 patients having a final diagnosis of ventricular tachycardia would have been correctly identified. It is concluded that the use of these two questions can be very helpful in improving the clinical diagnosis of ventricular tachycardia.