Differentiating wide complex tachycardias: A historical perspective

One of the most critical and challenging skills is the distinction of wide complex tachycardias into ventricular tachycardia or supraventricular wide complex tachycardia. Prompt and accurate differentiation of wide complex tachycardias naturally influences short- and long-term management decisions and may directly affect patient outcomes. Currently, there are many useful electrocardiographic criteria and algorithms designed to distinguish ventricular tachycardia and supraventricular wide complex tachycardia accurately; however, no single approach guarantees diagnostic certainty. In this review, we offer an in-depth analysis of available methods to differentiate wide complex tachycardias by retrospectively examining its rich literature base – one that spans several decades.     

A forgotten cause of wide complex tachycardia

Wide complex tachycardia secondary to an acute overdose from TCA's is a well-documented phenomenon. In this case we present a wide complex tachycardia after clear documentation of no acute overdose, which responded to standard treatment for TCA toxicity. These findings combined with chronic electrocardiographic abnormalities were suggestive of an acute on chronic TCA toxicity.     

食管心电生理检查鉴别宽QRS波心动过速

目的探讨食管电生理检查在宽QRS波心动过速的诊断应用价值。方法结合心内电生理检查结论,对42例宽QRS波群心动过速（WCT）发作时的食管心电图及体表心电图诊断进行回顾性比较分析,评价食管电生理在诊断WCT中的应用价值。结果与体表心电图诊断结果相比较,食管心电图对WCT的诊断准确度更高,而误诊率、漏诊率更低。结论应用食管电生理能显著提高对WCT的诊断和鉴别诊断水平,在心律失常的治疗上也具有实用价值。     

Full disclosure: Unraveling the mystery of a wide complex tachycardia

Wide complex tachycardia is not uncommon in patients with underlying structural heart disease and reduced ejection fraction. It is important to make the correct diagnosis as it carries prognostic and clinical implications. We present a case of a challenging wide complex rhythm detected on remote telemetry monitoring. This case outlines the differential diagnosis of a wide complex tachycardia and the clues to making a diagnosis of artifact. It highlights the importance of correct diagnosis as an incorrect diagnosis may lead to inappropriate treatments and unnecessary investigations.     

宽QRS波心动过速的鉴别诊断及治疗研究进展

宽QRS波心动过速是临床常见的心血管急症,可见于室性心动过速和部分室上性心动过速。室性心动过速是一种严重心律 失常,而室上性心动过速一般预后良好。由于二者的治疗原则不同,因此及时和正确地对宽QRS波心动过速进行鉴别诊断在临床 上有十分重要的意义。本文对宽QRS波心动过速的鉴别诊断和治疗原则予以综述。     

Automatic wide complex tachycardia differentiation using mathematically synthesized vectorcardiogram signals

BackgroundAutomated wide complex tachycardia (WCT) differentiation into ventricular tachycardia (VT) and supraventricular wide complex tachycardia (SWCT) may be accomplished using novel calculations that quantify the extent of mean electrical vector changes between the WCT and baseline electrocardiogram (ECG). At present, it is unknown whether quantifying mean electrical vector changes within three orthogonal vectorcardiogram (VCG) leads (X, Y, and Z leads) can improve automated VT and SWCT classification.MethodsA derivation cohort of paired WCT and baseline ECGs was used to derive five logistic regression models: (i) one novel WCT differentiation model (i.e., VCG Model), (ii) three previously developed WCT differentiation models (i.e., WCT Formula, VT Prediction Model, and WCT Formula II), and (iii) one “all‐inclusive” model (i.e., Hybrid Model). A separate validation cohort of paired WCT and baseline ECGs was used to trial and compare each model''s performance.ResultsThe VCG Model, composed of WCT QRS duration, baseline QRS duration, absolute change in QRS duration, X‐lead QRS amplitude change, Y‐lead QRS amplitude change, and Z‐lead QRS amplitude change, demonstrated effective WCT differentiation (area under the curve [AUC] 0.94) for the derivation cohort. For the validation cohort, the diagnostic performance of the VCG Model (AUC 0.94) was similar to that achieved by the WCT Formula (AUC 0.95), VT Prediction Model (AUC 0.91), WCT Formula II (AUC 0.94), and Hybrid Model (AUC 0.95).ConclusionCustom calculations derived from mathematically synthesized VCG signals may be used to formulate an effective means to differentiate WCTs automatically.     

Mayo Clinic VT calculator: A practical tool for accurate wide complex tachycardia differentiation

The discrimination of ventricular tachycardia (VT) versus supraventricular wide complex tachycardia (SWCT) via 12-lead electrocardiogram (ECG) is crucial for achieving appropriate, high-quality, and cost-effective care in patients presenting with wide QRS complex tachycardia (WCT). Decades of rigorous research have brought forth an expanding arsenal of applicable manual algorithm methods for differentiating WCTs. However, these algorithms are limited by their heavy reliance on the ECG interpreter for their proper execution. Herein, we introduce the Mayo Clinic ventricular tachycardia calculator (MC-VTcalc) as a novel generalizable, accurate, and easy-to-use means to estimate VT probability independent of ECG interpreter competency. The MC-VTcalc, through the use of web-based and mobile device platforms, only requires the entry of computerized measurements (i.e., QRS duration, QRS axis, and T-wave axis) that are routinely displayed on standard 12-lead ECG recordings.     

Application of a new algorithm in the differential diagnosis of wide QRS complex tachycardia.

AIMS: The Brugada criteria proposed to distinguish between regular, monomorphic wide QRS complex tachycardias (WCT) caused by supraventricular (SVT) and ventricular tachycardia (VT) have been reported to have a better sensitivity and specificity than the traditional criteria. By incorporating two new criteria, a new, simplified algorithm was devised and compared with the Brugada criteria. METHODS AND RESULTS: A total of 453 WCTs (331 VTs, 105 SVTs, 17 pre-excited tachycardias) from 287 consecutive patients with a proven electrophysiological (EP) diagnosis were prospectively analysed by two of the authors blinded to the EP diagnosis. The following criteria were analysed: (i) presence of AV dissociation; (ii) presence of an initial R wave in lead aVR; (iii) whether the morphology of the WCT correspond to bundle branch or fascicular block; (iv) estimation of initial (v(i)) and terminal (v(t)) ventricular activation velocity ratio (v(i)/v(t)) by measuring the voltage change on the ECG tracing during the initial 40 ms (v(i)) and the terminal 40 ms (v(t)) of the same bi- or multiphasic QRS complex. A v(i)/v(t) >1 was suggestive of SVT and a v(i)/v(t) 相似文献   

Griffith法Brugada法诊断宽QRS性室上性心动过速

为了解Griffith法和Brugada法诊断宽QRS性室上性心动过速（SVT）的价值，选择34例心电图表现为宽QRS心动过速者，其中SVT25例，室性心动过速（VT）9例，均经心脏电生理检查证实，采用上述两法进行了比较和综合分析。结果发现，Griffith法诊断SVT的敏感性、特异性和假阴性率分别为76％、77．8％和24％；而Brugada法的则分别为80％、88．9％和20％；两者合用时分别为84％、88．9％和16％。4例SVT为右侧旁路前传者均不符合诊断标准。认为，Griffith法和Brusada法或二者合用对SVT合并原有束支阻滞或室内差异性传导者有较高的诊断价值，而对预激旁路前传的SVT诊断价值低。     

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。     

Alternans during fascicular ventricular tachycardia due to digitalis toxicity

This report describes a digitalis-induced regular fascicular ventricular tachycardia characterized by marked QRS alternans a manifestation not usually associated with this arrhythmia. The striking alternation of QRS configuration suggested alternating ventricular activation from either a single focus with two exits in distal branches of the left anterior fascicle or 2 different foci localized in the Purkinje-myocardial network of the left anterior fascicle.     

室上性宽QRS波群心动过速的临床分析

目的对自发室上性宽QRS波群心动过速的临床特征、心电图特点进行分析,并用Brugada4步诊断法与室速进行鉴别诊断,评价其敏感性及特异性。方法选择入院时为心动过速的患者,符合窦性P波消失、心室率>100bpm且QRS波群时限≥0.12s,心脏电生理检查明确诊断后,采用单盲法回顾性分析12导联体表心电图的形态学特征,独立做出诊断后,计算Brugada4步诊断法的特异性和敏感性并评价其实用性,同时分析其临床特征及血液动力学改变。结果入选50例室上性宽QRS波群心动过速患者,46例诊断为室上速伴束支阻滞或心室内差异性传导,特异性92%,敏感性100%;心室率<180bpm组与心室率>180bpm组,两组的平均收缩压、平均舒张压及平均动脉压(平均动脉压=舒张压 1/3脉压)均有差别,心室率较快组血压较低,p值<0.05,差别有统计学意义。结论Brugada法对室上性宽QRS波群心动过速的鉴别诊断有重要意义,正确的诊断和及时的处理对患者至关重要。