Wide Complex Tachycardia in the Emergency Department: An Updated Approach to Diagnosis and Management (Pharmacology CME)

Table of Contents

 

About This Issue

Wide complex tachycardia (WCT) presents a significant diagnostic and therapeutic challenge in emergency medicine. Because no single electrocardiographic finding definitively distinguishes ventricular tachycardia from supraventricular causes, clinicians must integrate ECG interpretation with clinical context and response to therapy. Early recognition and appropriate management are critical to preventing hemodynamic collapse and improving patient outcomes. This issue reviews an updated, evidence-based approach to evaluating and managing WCT in the emergency department, including practical strategies for distinguishing underlying etiologies and selecting appropriate treatment pathways. In this issue, you will learn:

Key ECG findings and clinical features that help differentiate ventricular tachycardia from supraventricular tachycardia with aberrancy

How to assess hemodynamic stability and determine when immediate electrical therapy is required

Approaches to managing stable versus unstable wide complex tachycardia

The role of adenosine in diagnosis and treatment

Evidence-based selection of antiarrhythmic medications, including procainamide and amiodarone

Recognition and management of special scenarios, including hyperkalemia, toxicologic causes, and Wolff-Parkinson-White syndrome

The emerging role of artificial intelligence–assisted ECG interpretation

1. About This Issue
2. Abstract
3. Case Presentations
4. Introduction
5. Critical Appraisal of the Literature
6. Etiology and Pathophysiology
7. Differential Diagnosis
   1. Toxic Myocardium
      1. Cardiac Sodium-Channel Inhibitors
   2. Hyperkalemia
   3. Supraventricular Tachycardia
      1. Supraventricular Tachycardia With Aberrancy
      2. Supraventricular Tachycardia With an Accessory Pathway
8. Ventricular Tachycardia
   1. Monomorphic Ventricular Tachycardia
   2. Polymorphic Ventricular Tachycardia
   3. Bidirectional Ventricular Tachycardia
9. Paced Tachycardia
   1. Sinus Tachycardia With Paced Ventricular Response
   2. Pacemaker-Mediated Tachycardia
10. Prehospital Care
11. Emergency Department Evaluation
    1. History
    2. Physical Examination
12. Diagnostic Studies
    1. The Diagnostic Utility of Electrocardiography
       1. Heart Rate
       2. Axis
       3. QRS Duration and Morphology
       4. Concordance
       5. Atrioventricular Dissociation, Capture Complex, and Fusion Complex
       6. Comparison to Prior Electrocardiography
    2. Diagnostic Algorithms
       1. Diagnostic Utility
13. Adenosine Response
    1. Laboratory Testing
       1. Electrolytes
       2. Cardiac Biomarkers
14. Treatment
    1. Unstable Wide Complex Tachycardia
    2. Stable Wide Complex Tachycardia
    3. Treatment of Extrinsic Causes
15. Special Circumstances
    1. Irregular Wide Complex Tachycardia With Wolff-Parkinson-White Syndrome
    2. Outflow Tract Ventricular Tachycardia
    3. Wide Complex Tachycardia in the Patient With an Implantable Pacemaker
    4. Electrical Storm
16. Controversies and Cutting Edge
17. Disposition
18. Summary
19. Time- and Cost-Effective Strategies
20. 5 Things That Will Change Your Practice
21. Risk Management Pitfalls in the Emergency Department Management of Wide Complex Tachycardia
22. Case Conclusions
23. Clinical Pathways
    1. Clinical Pathway for Medical Management of Stable, Irregular Wide Complex Tachycardia
    2. Clinical Pathway for Initial Management of Stable, Regular Wide Complex Tachycardia
24. Tables and Figures
25. References

Abstract

Wide complex tachycardia encompasses a range of cardiac tachydysrhythmias, several of which can be life-threatening, difficult to distinguish, and require distinct treatment approaches. This review summarizes the etiologies and pathophysiology of wide complex tachycardia, outlines the differential diagnosis, and provides an evidence-based approach to distinguishing the various types using the history, physical examination, electrocardiography, and response to intravenous adenosine. Management strategies and disposition decisions are also reviewed, with attention to special clinical circumstances and selected areas of ongoing controversy, including emerging artificial intelligence tools.

Case Presentations

A 72-year-old man presents to the emergency department with shortness of breath…

• He is attached to the monitor and you see a wide complex tachycardia at a rate of 158 beats/min.
• His blood pressure is 128/73 mm Hg, and his pulse oximetry is 96% on ambient air.
• The patient sees you looking at the defibrillator and says, “I don’t want to be shocked. Are there any meds you can give me?”
• You consider which medications you should use for pharmacologic cardioversion of his ventricular tachycardia…

A 28-year-old woman presents to the emergency department with vomiting…

• She is treated with multiple rounds of antiemetics. As she is being prepared for transfer to the observation unit due to persistent oral intolerance, a nurse suddenly calls out for assistance.
• You arrive and check the monitor, where you see that the patient has a wide complex tachycardia with variable QRS morphology. You diagnose her with polymorphic ventricular tachycardia.
• She has a pulse. Her blood pressure is 60/30 mm Hg.
• As the nurses reach for pads to apply to the patient, you consider whether you need to synchronize the shock or defibrillate…

How would you manage these patients? Subscribe for evidence-based best practices and to discover the outcomes.

Clinical Pathway for Medical Management of Stable, Irregular Wide Complex Tachycardia

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Tables and Figures

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Key References

Following are the most informative references cited in this paper, as determined by the authors.

9. * Wigginton JG, Agarwal S, Bartos JA, et al. Part 9: adult advanced life support: 2025 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2025;152(16_suppl_2):S538-S577. (Clinical practice guidelines) DOI: 10.1161/CIR.0000000000001376

20. * Alblaihed L, Al-Salamah T. Wide complex tachycardias. Emerg Med Clin North Am. 2022;40(4):733-753. (Review) DOI: 10.1016/j.emc.2022.06.010

28. * Brady WJ, Mattu A, Tabas J, et al. The differential diagnosis of wide QRS complex tachycardia. Am J Emerg Med. 2017;35(10):1525-1529. (Review) DOI: 10.1016/j.ajem.2017.07.056

40. * Marill KA, Wolfram S, deSouza IS, et al. Adenosine for wide-complex tachycardia: efficacy and safety. Crit Care Med. 2009;37(9):2512-2518. (Retrospective; 197 patients) DOI: 10.1097/CCM.0b013e3181a93661

61. * Kashou AH, Noseworthy PA, DeSimone CV, et al. Wide complex tachycardia differentiation: a reappraisal of the state-of-the-art. J Am Heart Assoc. 2020;9(11):e016598. (Review) DOI: 10.1161/JAHA.120.016598

63. * Al-Khatib SM, Stevenson WG, Ackerman MJ, et al. 2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: executive summary: a report of the American College of Cardiology/American Heart Association task force on clinical practice guidelines and the Heart Rhythm Society. Circulation. 2018;138(13):e210-e271. (Clinical practice guideline) DOI: 10.1161/CIR.0000000000000548

84. * Zeppenfeld K, Tfelt-Hansen J, de Riva M, et al. 2022 ESC guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. Eur Heart J. 2022;43(40):3997-4126. (Clinical practice guidelines) DOI: 10.1093/eurheartj/ehac262

86. * Ortiz M, Martin A, Arribas F, et al. Randomized comparison of intravenous procainamide vs. intravenous amiodarone for the acute treatment of tolerated wide QRS tachycardia: the PROCAMIO study. Eur Heart J. 2017;38(17):1329-1335. (Randomized controlled trial; 74 patients) DOI: 10.1093/eurheartj/ehw230

94. * Cao D, Arens AM, Chow SL, et al. Part 10: adult and pediatric special circumstances of resuscitation: 2025 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2025;152(16_suppl_2):S578-S672. (Clinical practice guidelines) DOI: 10.1161/CIR.0000000000001380

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Keywords: wide complex tachycardia, ECG, EKG, ventricular tachycardia, wide QRS tachycardia, supraventricular tachycardia, VT, SVT, tachydysrhythmia, tachyarrhythmia, stable WCT, unstable WCT, adenosine, procainamide, amiodarone, Wolff-Parkinson-White, Brugada, Wells, atrial fibrillation, atrial flutter