Paediatric Arrhythmias Summary

Recognition

  • Bradycardia: HR <60 bpm, pre-terminal
  • Tachycardia:
    • Infants: >220 bpm
    • Children: >180 bpm
  • SVT: Narrow QRS, absent P waves
  • VT: Wide QRS complex

Causes

  • Bradycardia: Hypoxia, raised ICP, poisoning
  • Tachycardia: Congenital, poisoning, metabolic

Presentations

  • Verbal children: Palpitations
  • Pre-verbal: Poor feeding
  • Severe: Heart failure or shock

Bradycardia Management

  • ABC first - oxygen, ventilation, fluids
  • Adrenaline: 10 mcg/kg IV bolus
  • Atropine: 20 mcg/kg IV/IO

SVT Management

  • Shocked: Synchronized DC shock 1-2 J/kg
  • Stable: Vagal maneuvers → Adenosine
  • Adenosine: 100-500 mcg/kg (max 12 mg)

VT Management

  • Shocked: Synchronized DC shock 2-4 J/kg
  • Stable: Amiodarone 5 mg/kg over 20 min
  • Early paediatric cardiology consult

Key Medications

  • Adenosine: Rapid IV bolus for SVT
  • Amiodarone: 5 mg/kg over 20 min for VT
  • Adrenaline: 10 mcg/kg for bradycardia
  • Atropine: 20 mcg/kg for vagal stimulation

Paediatric Arrhythmias

Recognition and management of cardiac rhythm disturbances in children

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Recognition

Bradycardia

  • Heart rate <60 bpm
  • Rapidly falling HR with poor perfusion
  • Usually pre-terminal rhythm
  • Secondary to profound hypoxia/ischemia

Tachycardia

  • Sinus tachycardia:
    • Infants: up to 220 bpm
    • Children: up to 180 bpm
  • Tachyarrhythmia:
    • Infants: >220 bpm
    • Children: >180 bpm
    • ECG required for rates >200 bpm (infants) or >150 bpm (children)

ECG Characteristics

Arrhythmia Features
SVT Narrow QRS, absent P waves (most common non-arrest arrhythmia)
VT Wide QRS complex

Causes

Bradyarrhythmias

  • Hypoxia/shock (pre-terminal)
  • Raised ICP
  • Post-cardiac surgery
  • Congenital heart block
  • Long QT syndrome
  • Poisoning (digoxin, beta-blockers)

Tachyarrhythmias

  • Congenital conduction pathway abnormality
  • Poisoning (TCAs, procainamide, quinidine)
  • Metabolic (hyperkalemia)
  • Post-cardiac surgery
  • Cardiomyopathy/myocarditis
  • Channelopathies (e.g., long QT)

Presentations

Management of Bradycardias

ABC First!

Always assess and treat airway, breathing, circulation before pharmacological management

Hypoxia/Shock

  1. High-concentration oxygen
  2. Bag-mask ventilation/intubation
  3. Volume expansion (10ml/kg crystalloid)
  4. Chest compressions if needed
  5. Adrenaline:
    • 10 mcg/kg IV bolus (if above ineffective)
    • Infusion 0.05-2 mcg/kg/min (if still ineffective)

Vagal Stimulation

Poisoning

Management of SVT

Shocked Patient

  1. Vagal maneuvers only if no delay
  2. If IV access quicker than defibrillator: adenosine
  3. Otherwise synchronized DC shock:
    • First attempt: 1 J/kg
    • Second attempt: 2 J/kg (consider amiodarone)

Stable Patient

  1. Vagal stimulation with ECG monitoring:
    • Diving reflex (iced water to face)
    • Carotid sinus massage (one-sided)
    • Valsalva in older children
  2. If unsuccessful: Adenosine
    Attempt Dose Max Dose
    1 100 mcg/kg rapid IV bolus 500 mcg/kg (300 mcg/kg if <1 month)
    2 (after 2 min) 200 mcg/kg
    3 (after 2 min) 300 mcg/kg
    4* 400-500 mcg/kg Max total 12 mg
  3. If still unsuccessful: Consult paediatric cardiologist
    • Synchronized cardioversion
    • Amiodarone
    • Other antiarrhythmics (propranolol, flecainide, digoxin)

Management of VT (With Pulse)

Shocked Patient

  1. Synchronized DC shock 2 J/kg
  2. Repeat with 4 J/kg if needed
  3. Consider amiodarone
  4. If sync mode fails, may need asynchronous shock

Stable Patient

  • Early paediatric cardiology consult
  • Options:
    • Amiodarone 5 mg/kg over 20 min (30 min in neonates)
    • Procainamide
    • Verapamil
    • Synchronized cardioversion
  • Do not delay treatment - may deteriorate to pulseless VT/VF