Paeds · investigations-procedures-and-technology

Defibrillation, cardioversion and transcutaneous pacing

Also known as Paediatric defibrillation · Synchronised cardioversion · Transcutaneous pacing · External cardiac pacing · Shockable rhythm management

A fellowship approach to delivering an electric shock or an external pacing stimulus to a child's heart, covering the critical distinction between unsynchronised defibrillation for pulseless ventricular fibrillation and pulseless ventricular tachycardia at 4 joules per kilogram, synchronised cardioversion for a perfusing tachyarrhythmia such as supraventricular tachycardia at 1 joule per kilogram escalating to 2 joules per kilogram, and transcutaneous pacing for symptomatic bradycardia from complete heart block. The page teaches the energy doses, the pad positions (anterolateral and anteroposterior), automated external defibrillator use with attenuated paediatric pads in the under-eight-year-old, the sync function that prevents an R-on-T shock, capture thresholds and analgesia for pacing, and the complications of skin burns, myocardial injury and failure to capture. Every dose is anchored to the 2020 American Heart Association Pediatric Advanced Life Support guidance, the 2021 European Resuscitation Council Paediatric Life Support guidelines, and APLS.

high12 referencesUpdated 17 July 202621 min readVerification in progress

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RACP General PaediatricsRACP DWERACP DCERCPCH Progress+MRCPCH TheoryMRCPCH ClinicalABP General PediatricsACGME PediatricsRCPSC Pediatrics

Red flags

Ventricular fibrillation or pulseless ventricular tachycardia in a child — this is a shockable cardiac arrest rhythm; deliver an unsynchronised shock at 4 joules per kilogram immediately and resume compressions without a pulse checkDelivering a shock with the synchronisation function left ON for ventricular fibrillation — the defibrillator will not fire because it cannot find an R wave to synchronise toA child with supraventricular tachycardia who is shocked in unsynchronised mode — a shock landing on the T wave can precipitate ventricular fibrillation, so always switch SYNC on for a perfusing tachyarrhythmiaSymptomatic bradycardia with complete heart block that fails to respond to adrenaline — start transcutaneous pacing early rather than escalating inotropes indefinitelyUsing adult defibrillator pads that touch each other on the small chest of an infant — use anteroposterior placement or paediatric pads to avoid arcing between padsAn infant under one year shocked with an automated external defibrillator using adult energy when a manual defibrillator is available — a manual machine allows the weight-based 4 joules per kilogram dose

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General and Community PaediatricsRecognition and management of the acutely ill childProcedural skills — defibrillation and cardioversionEmergency and resuscitation medicineCurrent 2026 PREP curriculum — Learning Objective 2.2.1: Recognise, prioritise and manage an acutely ill infant, child or young person including management of shockable cardiac arrest rhythmsClinical ApplicationsMedical SciencesProcedural skillsShort CasesStructured oral — acutely ill or collapsing child1.4 Safely and appropriately performs practical procedures and uses medical devices4. Patient management8. Patient safetyFoundation of Practice (FOP)Applied Knowledge in Practice (AKP)Clinical — structured oral and communication in an emergencyGeneral Pediatrics Content Outline — Emergency Medicine; Procedural skillsUniversal Task 4: Management and TreatmentPatient Care 1: procedural competencySystems-Based PracticeMedical ExpertCollaboratorPediatrics: Procedural skill — defibrillation and cardioversion

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Target exams

RACP General PaediatricsRACP DWERACP DCERCPCH Progress+MRCPCH TheoryMRCPCH ClinicalABP General PediatricsACGME PediatricsRCPSC Pediatrics

Red flags

Life stages

neonateinfanttoddlerpreschoolschool-ageadolescent

Care settings

ed-acutenicupicuwardretrievalrural-remote

Clinical exam formats

written-only

Board mappings

The fellowship answer

The single distinction that governs everything in this topic is whether the child has a pulse. A pulseless child in ventricular fibrillation or pulseless ventricular tachycardia needs an unsynchronised shock — defibrillation — at 4 joules per kilogram, followed at once by two minutes of uninterrupted cardiopulmonary resuscitation. [1] [2] A child with a pulse and a perfusing but unstable tachyarrhythmia such as supraventricular tachycardia needs a synchronised shock — cardioversion — at 1 joule per kilogram, escalating to 2 joules per kilogram if the first shock fails. [1] [4]

The word that separates the two is synchronisation. Defibrillation fires the instant you press the button, on any part of the cardiac cycle, because in ventricular fibrillation there is no organised R wave to avoid. Cardioversion waits for the defibrillator to detect the R wave and discharges on the downstroke of the QRS, so the shock never lands on the vulnerable T wave and provokes ventricular fibrillation. Leaving SYNC on for ventricular fibrillation is a common and dangerous error, because the machine hunts for an R wave that does not exist and never fires. [1] [6]

Transcutaneous pacing is the third tool, used not for a tachyarrhythmia but for symptomatic bradycardia — most often complete heart block or sinus node dysfunction that has not responded to adrenaline. Pacing pads are placed on the chest and back, the rate is set near 80 to 100 per minute, and the output in milliamperes is increased from zero until each pacing spike is followed by a captured QRS and a palpable pulse. It is painful, so a conscious child needs analgesia and sedation, and it is a bridge to a transvenous wire. [5]

Overview & Definition

Picture a six-year-old in the emergency department with a heart rate of 250, pale and breathless, the monitor showing a narrow-complex tachycardia you cannot break with vagal manoeuvres. Now picture a different child, collapsed and pulseless, the monitor showing a chaotic writhing trace of ventricular fibrillation. Both need an electric shock, but the shocks are different, and confusing them can kill. This topic teaches the three ways electricity is delivered to a child's heart: defibrillation, cardioversion, and transcutaneous pacing. [1] [6]

Defibrillation is the unsynchronised delivery of a direct-current shock across the chest to a heart in ventricular fibrillation or pulseless ventricular tachycardia. The goal is to depolarise the whole myocardium at once, extinguish every re-entry circuit, and hand the sinus node a silent heart it can recapture. Synchronised cardioversion is a timed shock, discharged on the R wave, delivered to a heart that still has a perfusing rhythm — supraventricular tachycardia, atrial flutter, or a stable monomorphic ventricular tachycardia with a pulse — when drug therapy has failed or the child is haemodynamically unstable. Transcutaneous pacing is external electrical stimulation of a bradycardic heart through pads on the chest wall, used as a bridge when intrinsic conduction has failed. [1] [5]

The numbers a fellowship candidate must hold in one line are these: defibrillate ventricular fibrillation and pulseless ventricular tachycardia at 4 joules per kilogram; cardiovert a perfusing tachyarrhythmia at 1 joule per kilogram, escalating to 2 joules per kilogram; and pace a symptomatic bradycardia at a rate of 80 to 100 per minute, increasing the output until you see electrical and mechanical capture. [1] [2]

Paediatrics Fellowship Pro

You have read the opening of this topic. The complete unit — every section and its primary-source references — is part of the Paediatrics Fellowship fellowship atlas.

References12Show ledger

[1]Topjian AA, Raymond TT, Atkins D, et al Part 4: Pediatric Basic and Advanced Life Support 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Pediatrics, 2021.PMID 33087552
[2]Van de Voorde P, Turner NM, Djakow J, et al European Resuscitation Council Guidelines 2021: Paediatric Life Support Resuscitation, 2021.PMID 33773830
[3]Mercier E, Laroche E, Beck B, et al Defibrillation energy dose during pediatric cardiac arrest: Systematic review of human and animal model studies Resuscitation, 2019.PMID 31029714
[4]Brugada J, Blom N, Sarquella-Brugada G, et al Pharmacological and non-pharmacological therapy for arrhythmias in the pediatric population: EHRA and AEPC-Arrhythmia Working Group joint consensus statement Europace, 2013.PMID 23851511
[5]Neubrand TL, Topoz I, Mistry RD Updated Approaches to Cardiac Electrical Stimulation and Pacing in Pediatrics Pediatric Emergency Care, 2020.PMID 32868549
[6]Samson RA, Atkins DL Tachyarrhythmias and defibrillation Pediatric Clinics of North America, 2008.PMID 18675025
[7]Lupton JR, Newgard CD, Dennis D, et al Initial Defibrillator Pad Position and Outcomes for Shockable Out-of-Hospital Cardiac Arrest JAMA Network Open, 2024.PMID 39250154
[8]Atkins DL, Jorgenson DB Attenuated pediatric electrode pads for automated external defibrillator use in children Resuscitation, 2005.PMID 15993727
[9]Berg RA Attenuated adult biphasic shocks for prolonged pediatric ventricular fibrillation: support for pediatric automated defibrillators Critical Care Medicine, 2004.PMID 15508658
[10]Atkinson E, Mikysa B, Conway JA, et al Specificity and sensitivity of automated external defibrillator rhythm analysis in infants and children Annals of Emergency Medicine, 2003.PMID 12883506
[11]Morgan RW, Kirschen MP, Kilbaugh TJ, et al Pediatric In-Hospital Cardiac Arrest and Cardiopulmonary Resuscitation in the United States: A Review JAMA Pediatrics, 2021.PMID 33226408
[12]Abbasi E, Vijayashankar SS, Goldman RD Management of acute supraventricular tachycardia in children Canadian Family Physician, 2023.PMID 38092445

Defibrillation, cardioversion and transcutaneous pacing

Also known as Paediatric defibrillation · Synchronised cardioversion · Transcutaneous pacing · External cardiac pacing · Shockable rhythm management

high12 referencesUpdated 17 July 202621 min readVerification in progress

Practise this topic

Overview & Definition

Paediatrics Fellowship Pro

You have read the opening of this topic. The complete unit — every section and its primary-source references — is part of the Paediatrics Fellowship fellowship atlas.

References12Show ledger

[1]Topjian AA, Raymond TT, Atkins D, et al Part 4: Pediatric Basic and Advanced Life Support 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Pediatrics, 2021.PMID 33087552
[2]Van de Voorde P, Turner NM, Djakow J, et al European Resuscitation Council Guidelines 2021: Paediatric Life Support Resuscitation, 2021.PMID 33773830
[3]Mercier E, Laroche E, Beck B, et al Defibrillation energy dose during pediatric cardiac arrest: Systematic review of human and animal model studies Resuscitation, 2019.PMID 31029714
[4]Brugada J, Blom N, Sarquella-Brugada G, et al Pharmacological and non-pharmacological therapy for arrhythmias in the pediatric population: EHRA and AEPC-Arrhythmia Working Group joint consensus statement Europace, 2013.PMID 23851511
[5]Neubrand TL, Topoz I, Mistry RD Updated Approaches to Cardiac Electrical Stimulation and Pacing in Pediatrics Pediatric Emergency Care, 2020.PMID 32868549
[6]Samson RA, Atkins DL Tachyarrhythmias and defibrillation Pediatric Clinics of North America, 2008.PMID 18675025
[7]Lupton JR, Newgard CD, Dennis D, et al Initial Defibrillator Pad Position and Outcomes for Shockable Out-of-Hospital Cardiac Arrest JAMA Network Open, 2024.PMID 39250154
[8]Atkins DL, Jorgenson DB Attenuated pediatric electrode pads for automated external defibrillator use in children Resuscitation, 2005.PMID 15993727
[9]Berg RA Attenuated adult biphasic shocks for prolonged pediatric ventricular fibrillation: support for pediatric automated defibrillators Critical Care Medicine, 2004.PMID 15508658
[10]Atkinson E, Mikysa B, Conway JA, et al Specificity and sensitivity of automated external defibrillator rhythm analysis in infants and children Annals of Emergency Medicine, 2003.PMID 12883506
[11]Morgan RW, Kirschen MP, Kilbaugh TJ, et al Pediatric In-Hospital Cardiac Arrest and Cardiopulmonary Resuscitation in the United States: A Review JAMA Pediatrics, 2021.PMID 33226408
[12]Abbasi E, Vijayashankar SS, Goldman RD Management of acute supraventricular tachycardia in children Canadian Family Physician, 2023.PMID 38092445