The differential diagnosis of wide QRS complex tachycardia

Wide complex tachycardia is defined as a cardiac rhythm with a rate greater than 100 beats/min (bpm) and a QRS complex duration greater than 0.10 to 0.12 seconds (s) in the adult patient; wide complex tachycardia (WCT) in children is defined according to age-related metrics. The differential diagnosis of the WCT includes ventricular tachycardia and supraventricular tachycardia with aberrant intraventricular conduction, including both relatively benign and life-threatening dysrhythmias. This review focuses on the differential diagnosis of WCT with a discussion of strategies useful in making the appropriate diagnosis, when possible.     

Noninvasive diagnosis of a wide QRS complex tachycardia mechanism by programmed atrial and ventricular stimulation using a dual chamber defibrillator

Stored atrial and ventricular electrograms retrieved from dual chamber implantable defibrillators facilitate the diagnosis of arrhythmias. This case also illustrates the usefulness of programmed atrial and ventricular stimulation for noninvasive rhythm diagnosis in patients with a wide QRS tachycardia and an implantable defibrillator.     

肢体导联反向法和室性心动过速积分法在鉴别预激性心动过速中的临床价值

目的探讨肢体导联反向法和室性心动过速（VT）积分法在鉴别预激性心动过速中的临床价值。 方法回顾性分析2013年1月至2021年6月首都医科大学附属北京友谊医院经心内电生理确诊为预激性心动过速的住院患者18例，收集患者发作时的12导联心电图，分别采用肢体导联反向法和VT积分法进行评分。采用χ²检验比较二者诊断预激性心动过速的特异度差异，并分析2种流程诊断预激性心动过速不同类型和不同旁路位置中的特异度。 结果18例患者中，肢体导联反向法诊断的真阳性11例，特异度为38.89%；VT积分法积分≥2分、≥3分诊断预激性心动过速的特异度分别为55.56%、100.00%。肢体导联反向法与VT积分法积分≥2分诊断预激性心动过速的特异度比较，差异无统计学意义（P＞0.05）；肢体导联反向法与VT积分法积分≥3分的特异度比较，差异有统计学意义（P＜0.05）。2种诊断流程对不同类型和旁路位置预激性心动过速诊断的特异度差异无统计学意义（P＞0.05）。 结论VT积分法积分≥3分可区分预激性心动过速和VT，肢体导联反向法和VT积分法≥2分则不能区分。     

Wide-complex Tachycardia: Continued Evaluation of Diagnostic Criteria

OBJECTIVE: To evaluate the accuracy of the Brugada algorithm for analysis of wide-complex tachycardia (WCT) when applied by board-certified emergency physicians and board-certified cardiologists. METHODS: A database consisting of 157 electrocardiograms of WCTs were evaluated in a blinded fashion using the Brugada criteria to determine the presence of ventricular tachycardia (VT) or supraventricular tachycardia with aberrancy. These results were then compared with the electrophysiologically proven diagnosis for each tracing. Sensitivity and specificity of the Brugada criteria for diagnosis of VT were calculated. Two board-certified emergency physicians and two board-certified cardiologists analyzed each tracing, and interobserver agreement was determined using the kappa statistic. RESULTS: Sensitivity and specificity for the determination of VT using the Brugada algorithm were 85% [95% confidence interval (95% CI) = 79% to 91%] and 60% (95% CI = 43% to 78%) for cardiologist 1 (C 1) and 91% (95% CI = 86% to 96%) and 55% (95% CI = 37% to 72%) for C 2. Emergency physician (EP 1) achieved a sensitivity of 83% (95% CI = 78% to 91%) and a specificity of 43% (95% CI = 25% to 59%), while EP 2 attained 79% (95% CI = 73% to 87%) and 70% (95% CI = 51% to 84%), respectively. The original authors achieved a sensitivity of 98.7% and specificity of 96.5% when determining VT in their study population. Interobserver agreement for the emergency physicians and the cardiologists in determining VT was 82% and 81%, respectively. CONCLUSIONS: Neither the emergency physicians nor the cardiologists were able to achieve a sensitivity or specificity as high as that reported by the original investigators when using the Brugada algorithm to determine the presence of VT.     

Wide‐QRS‐Complex Tachycardia with a Negative Concordance Pattern in the Precordial Leads: Are the ECG Criteria Always Reliable?

We present a case of wide-complex tachycardia with negative concordance in the precordial leads and a qR pattern in V6, in a 42-year-old man with risk factors for coronary artery disease, in whom the electrocardiogram criteria were apparently fallible. This case highlights the key contribution of the electrophysiological study in rendering correct diagnosis.     

Pseudoephedrine-induced paroxysmal supraventricular tachycardia: a case report

Palpitation is a common chief complaint among emergency department patients, and is often associated with a tachydysrhythmia. Tachydysrhythmia is classified as supraventricular tachycardia or ventricular tachycardia. Reentry in a normal or accessory pathway is one of the most frequently seen mechanisms explaining the tachydysrhythmia. In the present case, we report an unusual cause of atrioventricular paroxysmal supraventricular tachycardia due to pseudoephedrine intake.     

Infraatrial supraventricular tachycardias: mechanisms, diagnosis, and management

Tachycardias are traditionally classified as either ventricular tachycardia (VT) or supraventricular tachycardia (SVT). VT can be defined as a tachycardia which requires only ventricular structures for perpetuation. SVT is defined in terms of exclusion of VT and hence is any tachycardia which requires participation of at least one supraventricular structure for perpetuation. Certain SVTs require only participation of the atrioventricular node (AVN) and the His bundle (HB) but not the atrial myocardium or any of the great thoracic veins for perpetuation and hence can be described as "infraatrial." The three main mechanisms of infraatrial SVTs are: (1) intranodal atrioventricular reentrant tachycardia; (2) junctional ectopic tachycardia; and (3) nodoventricular reentrant tachycardia. The clinical significance of infraatrial SVTs is that they are compatible with any A:V ratio and even atrioventricular (AV) dissociation. Infraatrial SVTs are often suspected when a narrow complex tachycardia presents with apparent AV dissociation and a counterintuitive A:V ratio of < 1:1. However, if the same tachycardia is conducted with aberrant conduction or preexcitation, a broad complex tachycardia with an A:V ratio of < 1:1 will arise and that can be easily mistaken for VT. The possible patterns of electrical association and dissociation between different cardiac structures are examined, and how individual types of infraatrial SVT can be diagnosed and managed are reviewed.     

Electrocardiographic differential diagnosis of narrow QRS complex tachycardia: an ED-oriented algorithmic approach

The differentiation of narrow complex tachycardias is a common diagnostic conundrum encountered by emergency physicians. Although a number of published algorithms are available to assist the clinician in evaluating features of the 12-lead electrocardiogram (ECG), many of these are too cumbersome, requiring multiple decisions and introducing treatment suggestions within the diagnostic framework. To optimize the diagnosis of the narrow complex tachycardia, we propose 3 separate algorithms tailored to address varying levels of available clinical information. The static algorithm depends only on the 12-lead ECG without the benefit of historical data or diagnostic interventions. The comparative algorithm requires a baseline ECG to which the presenting ECG is compared. The dynamic algorithm encourages the clinician to take advantage of diagnostic maneuvers to further elucidate the tachycardia mechanism. Each of these algorithms requires the clinician to answer either “yes” or “no” for each criterion and does not include treatment recommendations.     

宽QRS波心动过速鉴别诊断的临床分析

目的分析和对比宽QRS波心动过速(WCT)的鉴别诊断流程图的应用价值。方法对就诊于我院急诊科及心内科并经食管心房调搏、心内电生理检查或射频消融治疗而明确诊断的WCT患者,回顾性分析其病史、心电图、食管调搏或电生理检查及射频消融治疗的结果,研究Brugada四步法、无人区电轴联合aVR导联四步法对WCT诊断的准确率。结果82例WCT患者中,63例为室性心动过速,15例为室上性心动过速伴差异传导,3例为室上性心动过速伴预激前传,1例为双旁道间折返性心动过速。应用Brugada四步法正确诊断71例,正确诊断率86.6%;联合应用无人区电轴及aVR导联四步法,正确诊断75例患者,正确诊断率91.5%。结论联合应用无人区电轴及aVR导联四步法,可使大部分WCT得以正确诊断,提高WCT鉴别诊断的准确率。     

Paroxysmal supraventricular tachycardia in an octogenarian

Background

Paroxysmal supraventricular tachycardia is a common dysrhythmia that occurs at all ages. Its management is determined by presenting symptoms and previous history of the patient. Patients present with a continuum of symptoms ranging from palpitations to syncope. The incidence of supraventricular tachycardia increases with age.

Objectives

To discuss the etiology, precipitating factors, and acute management of supraventricular tachycardia; and to discuss nodal reentry circuits and representative electrocardiographic findings.

Case Report

We present the case of an 84-year-old man with gallstone pancreatitis, choledolcholithiasis, and cholecystitis complicated by paroxysmal supraventricular tachycardia. We review this dysrhythmia, emphasizing its significance in elderly patients.

Conclusion

Supraventricular tachycardia is a common dysrhythmia that can result in syncope or myocardial infarction. We present a case of an elderly man with new-onset atrioventricular (AV) nodal reentry tachycardia, possibly precipitated by overdrive of his autonomic nervous system due to pain and infection. As the percentage of the elderly in our population is growing rapidly and the incidence of AV nodal reentry tachycardia increases with age, emergency physicians should be familiar with this dysrhythmia—its etiology, precipitating factors, presentations, and treatment. It will present more frequently in the future.     

Supraventricular tachycardia with a baseline ECG pattern of Brugada syndrome

The typical arrhythmias found in patients with the Brugada syndrome is either ventricular fibrillation or polymorphic ventricular tachycardia. We report the case of a patient who presented with supraventricular tachycardia accompanied by ECG features of the Brugada syndrome (BrS) during both tachyarrhythmia and sinus rhythm. This case lends support to the recently reported association between supraventricular tachyarrhythmia and BrS and the hypothesis that the arrhythmogenic substrate in BrS is not limited to the ventricular level.     

Electrophysiological Significance of QRS Alternans in Narrow QRS Tachycardia

To investigate the electrophysiological significance of QRS alternans during narrow QRS tachycardia, transesophageal atrial pacing and recording was performed in 24 patients with a history of paroxysmal supraventricular tachycardia. Standard electrocardiograms showed ventricular preexcitation in 15 patients and normal QRS pattern in nine patients. The ventriculoatrial interval during tachycardia, as defined by means of transesophageal electrogram, allowed tentative diagnosis of the tachycardia mechanism. A 12-lead ECG was recorded either during spontaneous or induced tachycardia, as well as during transesophageal atrial pacing at increasing rates. Electrical alternans occurred spontaneously in eight patients (33%, group A): five with accessory pathway reentry (mean VA: 136 +/- 43 msec), and three with AV nodal reentry (mean VA: 48.3 +/- 12 msec). Tachycardia rate ranged between 170 and 230 beats/min (mean 200.7 +/- 16). In two patients, alternation of the QRS occurred only in the presence of a heart rate exceeding 180 and 190 beats/min, respectively. The amplitude of QRS remained stable during tachycardia in 16 patients (67%, group B): 14 had accessory pathway reentry (mean VA: 137.5 +/- 32 msec), and two had AV nodal reentry (mean VA: 45 +/- 7 msec). In this group, the tachycardia rate ranged from 150 to 210 beats/min (mean 175 +/- 12). Incremental transesophageal atrial pacing up to rates equal to that of tachycardia was performed in five patients from group A and in five patients from group B. Electrical alternans could not be induced in both groups with pacing at progressively increasing rates.(ABSTRACT TRUNCATED AT 250 WORDS)     

An unusual cause of ventricular tachycardia

Inflammatory pseudotumour (IP) of the heart is an extremely uncommon and potentially fatal lesion which presents a challenging diagnosis even for the experienced pathologist, cardiologist and cardiac surgeon. This spindle cell tumour is known to be present in virtually every anatomical region but, in adults, has only previously been found in the heart at postmortem. We report the case of a 27-year-old man who presented with ventricular tachyarrhythmias and a right ventricular mass which was subsequently shown to be an IP.     

Alternans in QRS amplitude during ventricular tachycardia

Although the value of T wave alternans as an index of electrical instability has been extensively investigated, little is known about QRS alternans during VT. Intracardiac electrograms of 111 episodes of spontaneous monomorphic regular VT retrieved from implantable defibrillators in 25 patients were retrospectively selected. Three beat series, representing the total amplitudes and amplitudes from baseline to summit and from baseline to lower point of 16 or 32 successive QRS complexes before deliverance of electrical therapy were generated for each episode. Spectral analysis was then performed using the fast Fourier transform. VT was considered as alternans if the magnitude of the spectral power at the 0.5-cycle/beat frequency was greater than the mean +/- 3 SD of the noise in at least one of the three spectral curves. QRS alternans was present in 23 (20%) of 111 episodes and in 9 (36%) of 25 patients. Alternans was not related to the VT cycle length, QRS duration, QRS amplitude, signal amplification, nor to clinical variables. Alternans was more frequently detected in unipolar configuration and when a higher number of complexes was included in analysis. Failure of antitachycardia pacing was more frequent in case of alternans VT (50% vs 75% success in nonalternans VT, P = 0.05). Spontaneous termination before deliverance of therapy occurred in 16 non-alternans VT but never in alternans episodes (P = 0.02). Alternans in QRS amplitude is a relatively common finding during VT and could be associated with failure of antitachycardia pacing and lack of spontaneous termination. Lower efficacy of electrical therapies in case of QRS alternans must be confirmed in a way to improve the effectiveness of antitachycardia pacing.     

静脉注射美托洛尔治疗室上性心动过速疗效观察

目的 评价静脉注射美托洛尔终止室上性心动过速（SVT）发作的疗效及安全性。方法 将我院门诊就诊或住院治疗的66例SVT患者,随机分成美托洛尔组（30例）和胺碘酮组（36例）,两组分别缓慢静脉注射美托洛尔或胺碘酮,比较终止SVT的有效率及不良反应。结果 美托洛尔组治疗后显效17例、有效4例,无效9例,有效率70．0％;胺碘酮组治疗后有显著效果18例、有效5例,无效13例,有效率63．9％,关托洛尔和胺碘酮两组治疗SVT的疗效比较,差异无统计学意义（P=0．572）。未观察到美托洛尔或胺碘酮组治疗后有明显的不良反应。结论 美托洛尔是一种安全的、比较有效的终止SVT的药物。