Volume 4, Number 3;  July 07, 2005

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Patient:

77 year old male with coronary artery disease, diabetes mellitus, hypertension; presenting with 2 weeks of SOB and DOE, fatigue, orthopnea.

Clinical Question: 

1) What are some recognized criteria for the diagnosis of wide complex tachycardia, and how well do the criteria perform?

Readings:

<3>

Unique Identifier [PMID]: 12049375

Authors: Lau EW. Ng GA.

Institution: Department of Cardiology, Queen Elizabeth Hospital, Edgbaston, Birmingham, United Kingdom. e.w.lau@bham.ac.uk

Title: Comparison of the performance of three diagnostic algorithms for regular broad complex tachycardia in practical application.

Source: Pacing & Clinical Electrophysiology. 25(5):822-7, 2002 May.

Abstract: The authors previously proposed a Bayesian approach to the electrocardiographic diagnosis of regular broad complex tachycardia (BCT), which can be due to VT or supraventricular tachycardia with aberrant conduction (SVTAC). They also published an account comparing the theoretical merits in the design of two of the most commonly used diagnostic algorithms for the same purpose, those of Brugada et al. and Griffith et al. In this study, a direct head-to-head comparison was performed on the practical performances of the three algorithms in this study. A set of 111 ECGs showing regular BCT (77 VT, 34 SVTAC) whose diagnoses were confirmed by electrophysiological study was shown to five internists in general medicine at a district general hospital. The observers were asked to comment on whether the ECG criteria in the three algorithms tested were fulfilled or not, and a computer program then derived the corresponding diagnoses. The sensitivity and specificity for VT achieved by the Brugada algorithm were 92% and 44%, 92% and 44% by the Griffith algorithm, and 97% and 56% by the Bayesian algorithm. The Bayesian algorithm achieved a higher sensitivity and specificity than the other two algorithms, but the differences are not statistically significant (P = 0.6583 and P = 0.5334, respectively). The Brugada, Griffith, and Bayesian algorithms show comparable performances in terms of overall sensitivity and specificity when tested in practice. Of the three algorithms, the Griffith algorithm excels in simplicity and is the easiest to implement in practice. The Bayesian algorithm achieved slightly higher values for sensitivity and specificity than the Brugada and Griffith algorithms but may be more suitable for automated computer-aided diagnosis of ECG due to its complexity.

Publication Type: Journal Article.

 Link Directly to Fulltext article in Ovid

<4>

Unique Identifier [PMID]: 11602560

Authors: Wellens HJ.

Institution: Interuniversity Cardiology Institute of the Netherlands (ICIN), Utrecht, The Netherlands. hwellens@xs4all.nl

Title: Electrophysiology: Ventricular tachycardia: diagnosis of broad QRS complex tachycardia. [Review] [13 refs]

Source: Heart (British Cardiac Society). 86(5):579-85, 2001 Nov.

Publication Type: Journal Article. Review. Review, Tutorial.

<8>

Unique Identifier [PMID]: 11060873

Authors: Lau EW. Pathamanathan RK. Ng GA. Cooper J. Skehan JD. Griffith MJ.

Institution: Department of Cardiology, Queen Elizabeth Hospital, Edgbaston, Birmingham, United Kingdom. e.w.lau@bham.ac.uk

Title: The Bayesian approach improves the electrocardiographic diagnosis of broad complex tachycardia.

Source: Pacing & Clinical Electrophysiology. 23(10 Pt 1):1519-26, 2000 Oct.

Abstract: Despite numerous attempts at devising algorithms for diagnosing broad complex tachycardia (BCT) on the basis of the electrocardiogram (ECG), misdiagnosis is still common. The reason for this may lie with difficulty in implementing existent algorithms in practice, due to imperfect ascertainment of ECG features within them. An attempt was made to approach the problem afresh with the Bayesian inference by the construction of a diagnostic algorithm centered around the likelihood ratio (LR). Previously studied ECG features most effective in discriminating ventricular tachycardia (VT) from supraventricular tachycardia with aberrant conduction (SVTAC), according to their LR values, were selected for inclusion into a Bayesian diagnostic algorithm. A test set of 244 BCT ECGs was assembled and shown to three independent observers who were blinded to the diagnoses made at electrophysiological study. Their diagnostic accuracy by the Bayesian algorithm was compared against that by clinical judgement with the diagnoses from EPS as the criterial standard. Clinical judgement correctly diagnosed 35% of SVTAC, 85% of VT, and 47% of fascicular tachycardia. In comparison, by the Bayesian algorithm devised, 52% of SVTAC, 95% of VT, and 97% of fascicular tachycardia were correctly diagnosed. The Bayesian algorithm devised has proved to be superior to the clinical judgement of the observers who participated in this study, and theoretically will obviate the problem of imperfect ascertainment of ECG features. Hence, it holds the promise for being an effective tool for routine use in clinical practice.

Publication Type: Journal Article.

Link Directly to Fulltext Article at Publisher

<9>

Unique Identifier [PMID]: 10917326

Authors: Isenhour JL. Craig S. Gibbs M. Littmann L. Rose G. Risch R.

Institution: Vanderbilt University Medical Center, Department of Emergency Medicine, Nashville, TN 37232, USA. jennifer_isenhour@mcmail.vanderbilt.edu

Title: Wide-complex tachycardia: continued evaluation of diagnostic criteria.[see comment].

Comments Comment in: Acad Emerg Med. 2001 Mar;8(3):300-1; PMID: 11229960

Source: Academic Emergency Medicine. 7(7):769-73, 2000 Jul.

Abstract: 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.

Publication Type: Evaluation Studies. Journal Article.

<24>

Unique Identifier [PMID]: 2022022

Authors: Brugada P. Brugada J. Mont L. Smeets J. Andries EW.

Institution: Cardiovascular Center, Postgraduate School of Cardiology, OLV Hospital, Aalst, Belgium.

Title: A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex.[see comment].

Comments Comment in: Circulation. 1992 May;85(5):1955-6; PMID: 1572055, Comment in: Circulation. 2001 May 29;103(21):E109-9; PMID: 11382741

Source: Circulation. 83(5):1649-59, 1991 May.

Abstract: 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.

Publication Type: Journal Article.

Resident Report / Department of Medicine & Grady Branch Library

Emory University School of Medicine

2005 Edition

Participating Faculty:  Carlos Del Rio MD  / Joyce Doyle MD / Lorenzo Difrancesco MD / Erich Folch MD / Alicia Hidron  MD  

Contact: Karl Woodworth