Narrow Complex Tachycardia


Two main categories:

  1. AV node independent
  2. AV node dependent


  1. sinus tachycardia
  2. atrial tachycardia (unifocal/multifocal)
  3. atrial fibrillation
  4. atrial flutter


  1. AV node re-entry tachycardia
  2. AV re-entry tachycardia
  3. junctional tachycardia


Undifferentiated Narrow Complex Tachycardia

  • vagal manoeuvre
  • adenosine 6-12mg IV (half dose if cardiac transplant or on dipryidamole)
  • -> AV node independent: decreased AV node conduction but tachycardia persists
  • -> AV node dependent: arrhythmia ceases

Ventricular stand-still post Adenosine

  • wait! (typically resolves after a few seconds)
  • theophylline 250mcg
  • atropine
  • adrenaline
  • CPR


Sinus tachycardia

  • treat cause!

Atrial tachycardia (unifocal or multifocal)

  • diagnose by taking an atrial electrogram (CVL, atrial epicardial, oesophageal)
  • stop digoxin and theophylline (cause or worsen arrhythmia)
  • Mg2+
  • K+
  • amiodarone
  • beta-blocker — sotalol if unifocal
  • synchronized cardioversion

Atrial fibrillation

  • stable: treat cause, cardiovert (replace electrolytes, amiodarone, flecanide), rate control (beta blockers, digoxin, amiodarone, sotalol, Ca2+ channel blockers), anti-coagulation
  • unstable: synchronized cardioversion

Atrial flutter

  • type I: rate 240-320 -> can overdrive pace
  • type II: rate 340-430 -> can’t overdrive pace
  • drugs: digoxin, diltiazem, beta blockers, sotalol, flecanide, procainamide and amiodarone
  • synchronised cardioversion (25-50J)


AV Node Re-entry Tachycardia

  • vagal manoeuvres
  • adenosine
  • verapamil
  • sotalol
  • amiodarone
  • flecanide
  • overdrive pacing
  • cardioversion

AV Re-entry Tachycardia

  • vagal manoeuvres
  • adenosine
  • sotalol
  • amiodarone
  • flecanide
  • overdrive pacing
  • cardioversion

-> same EXCEPT avoidance of verapamil as leads to rapid conduction down accessory pathway (WPW).

Junctional Tachycardia

  • amiodarone
  • flecanide


  • vagal manoeuvres
  • adenosine
  • treat cause (infection, hyperthyroidism, lung disease)
  • withdraw precipitants (digoxin or theophylline may be worsening arrhythmia)
  • replace electrolytes (Mg2+ and K+)


  1. amiodarone
  2. beta blockers
  3. sotalol
  4. flecanide
  • Digoxin – not in uni or multifocal atrial tachycardia or AV dependent arrhythmias
  • Verapamil – not in AV node re-entry tachcardia


  • overdriving atrial pacing: junctional tachycardia, AV and AV node re-entry tachycardia, type 1 atrial flutter
  • cardioversion

Long term

  • refer those with WPW (don’t medicate)
  • ablation therapy

CCC 700 6

Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

One comment

  1. Please clarify
    Under the heading of Management
    Under subheading AV NRT- Verapamil is chosen as treatment option
    The next subheading AV RT- ” same EXCEPT avoidance of verapamil as leads to rapid conduction down accessory pathway (WPW)”

    Further down the passage
    Under the heading General Management
    ” Verapamil – not in AV node re-entry tachcardia”

    Contradictory statement?

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