What are the major types of tachyarrhythmias and their corresponding ECG (electrocardiogram) findings?

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From the Guidelines

Tachyarrhythmias can be classified into several major types based on their origin and ECG findings, including supraventricular tachycardias, such as sinus tachycardia, atrial fibrillation, atrial flutter, and AV nodal reentrant tachycardia, as well as ventricular tachyarrhythmias, including ventricular tachycardia and ventricular fibrillation, as described in the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1.

Major Types of Tachyarrhythmias

  • Supraventricular tachycardias:
    • Sinus tachycardia: normal P waves, regular rhythm
    • Atrial fibrillation: irregularly irregular rhythm with no distinct P waves, often with a "sawtooth" baseline
    • Atrial flutter: regular rhythm with characteristic "flutter" waves
    • AV nodal reentrant tachycardia (AVNRT): hidden P waves or P waves immediately after QRS complexes
  • Ventricular tachyarrhythmias:
    • Ventricular tachycardia: wide QRS complexes, often >120 ms, with AV dissociation
    • Ventricular fibrillation: chaotic, irregular ventricular activity without discernible QRS complexes

ECG Findings

  • A 12-lead ECG obtained during tachycardia and during sinus rhythm may reveal the etiology of tachycardia, as stated in the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1
  • The presence of atrioventricular (AV) dissociation or fusion complexes provides the diagnosis of ventricular tachycardia, as noted in the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1
  • Other criteria, such as the Brugada criteria and the Vereckei algorithm, can be used to distinguish ventricular tachycardia from supraventricular tachycardia, as described in the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1

Importance of Accurate Diagnosis

  • Prompt recognition of these patterns is crucial for appropriate management, as treatment approaches vary significantly depending on the specific arrhythmia mechanism and the patient's hemodynamic stability, as emphasized in the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1

From the Research

Major Types of Tachyarrhythmias

  • Supraventricular tachycardias (SVTs) include:
    • Atrial flutter
    • Atrial fibrillation
    • Paroxysmal supraventricular tachycardia (PSVT)
    • Multifocal atrial tachycardia
  • Ventricular tachycardias include:
    • Ventricular tachycardia (VT)
    • Ventricular fibrillation (VF)
    • Torsade de pointes

ECG Findings

  • SVTs are characterized by a rapid heart rate originating from above the ventricles 2
  • Atrial flutter is characterized by a regular, rapid atrial rhythm with a consistent atrioventricular (AV) block 3
  • Atrial fibrillation is characterized by an irregular, rapid atrial rhythm with an irregular ventricular response 4
  • VT is characterized by a rapid, wide-complex rhythm originating from the ventricles 2
  • VF is characterized by a disorganized, chaotic rhythm with no discernible P waves or QRS complexes 2

Diagnosis and Management

  • Diagnosis of tachyarrhythmias involves a comprehensive history and physical examination, electrocardiography, and laboratory workup 3
  • Management of SVTs includes vagal maneuvers, adenosine, beta blockers, and calcium channel blockers 3, 4
  • Management of VT and VF includes cardioversion and defibrillation 2, 5
  • Cardioversion is a widely used procedure for converting atrial fibrillation and atrial flutter to sinus rhythm 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Cardiac arrhythmias: diagnosis and management. The tachycardias.

Critical care and resuscitation : journal of the Australasian Academy of Critical Care Medicine, 2002

Research

Supraventricular tachycardia: An overview of diagnosis and management.

Clinical medicine (London, England), 2020

Research

Cardioversion of atrial fibrillation and atrial flutter revisited: current evidence and practical guidance for a common procedure.

Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology, 2020

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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