Narrow Complex Tachycardia
OVERVIEW
Two main categories:
- AV node independent
- AV node dependent
AV NODE INDEPENDENT
- sinus tachycardia
- atrial tachycardia (unifocal/multifocal)
- atrial fibrillation
- atrial flutter
AV NODE DEPENDENT
- AV node re-entry tachycardia
- AV re-entry tachycardia
- junctional tachycardia
MANAGEMENT
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
AV NODE INDEPENDENT
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 DEPENDENT
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
GENERAL MANAGEMENT
- vagal manoeuvres
- adenosine
- treat cause (infection, hyperthyroidism, lung disease)
- withdraw precipitants (digoxin or theophylline may be worsening arrhythmia)
- replace electrolytes (Mg2+ and K+)
Drugs
- amiodarone
- beta blockers
- sotalol
- flecanide
- Digoxin – not in uni or multifocal atrial tachycardia or AV dependent arrhythmias
- Verapamil – not in AV node re-entry tachcardia
Electricity
- 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
References and Links
- ECG Library — ECG rhythm analysis
- ECG Library — ECG Clinical cases
- ECG Library — A to Z by Diagnosis
- Wiesbauer F. Atrial Fibrillation Management Essentials. Medmastery
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC
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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?