PAEDIATRIC
ECG MANUAL INTERPRETATION
Systematic Checklist
0 of 11 steps completed
Step 0 — Screen First
RED FLAGS — Tick All That Apply
Any single positive flag = immediate referral to Paediatrics / Cardiology
Syncope during exertion, without warning, or recurrent episodes
Syncope whilst lying down, supine, or sitting
Syncope whilst swimming
Chest pain on exertion or associated with syncope / palpitations
Palpitations with dizziness, syncope, or sudden onset and offset
Family history of sudden death under 40 years or inherited cardiac disease
Unexplained shortness of breath or collapse — consider PE
Steps 1–11 — Interpret Sequentially
Systematic Interpretation — 0 / 11 steps completed
1
Rate
Is the heart rate appropriate for the child's age?
Neonate 100–180 · Infant 100–190 · 2–5 yr 75–140 · 6–12 yr 70–120 · >12 yr 60–100 bpm
2
Rhythm
Is there a P-wave preceding every QRS complex?
3
Axis
Is the QRS complex positive in leads I and aVF?
Right axis deviation with positive aVF and negative lead I is normal in children under 1 year.
4
PR Interval
Is the PR interval between 3 and 5 small boxes?
Normal range: 120–200 ms (3–5 small boxes). If under 3 boxes (<120 ms) — check for delta wave (WPW). Over 5 boxes (>200 ms) = 1st degree heart block. Source: GOS/Evelina proforma Sep 2025.
5
QRS Interval
Are QRS complexes less than 3 small boxes wide?
Pathological threshold: >3 small boxes (>120 ms). Normal range widens with age: neonates ~70–85 ms, adolescents up to ~110 ms. Source: RCH guideline / Dickinson Heart 2005 / Rijnbeek.
6
QT Interval
Is the QTc less than 460 ms?
Bazett formula: QTc = QT ÷ √RR · Measure in lead II or V5.
7
RV Dominance / Hypertrophy
Is the R-wave smaller than the S-wave in V1?
Dominant R > S in V1 = RV dominance. Normal in children under 3 years. Persisting after age 3 suggests RVH. Source: GOS/Evelina proforma Sep 2025 / TeachMePaediatrics.
8
RV Hypertrophy
Is there clear separation with no overlap between R-wave of V6 and S-wave of V5?
9
Q-Waves
Are Q-waves less than 5 mm deep AND less than 1 small box wide in all leads?
Depth: <5 mm (children over 3 yrs). Width: <1 small box (<40 ms). Wide Q-waves suggest myocardial infarction or HCM. Source: Lambrechts BJA Education 2020.
10
T-Waves
Are T-waves positive in V5 and V6?
Under 8 yrs: negative T in V1 is normal. Over 8 yrs: negative T in V1 may still be normal.
11
ST Segment
If ST elevation is present, is it raised by less than 2 small boxes?
Disposition Guide
Flags
Electronic
Manual
Decision
No
Normal
Normal
Safe to discharge
No
Normal
Abnormal
Senior review
No
Abnormal
Normal
Senior review
No
Abnormal
Abnormal
Refer — Paeds / Cardiology
Yes
Any
Any
Refer — Paeds / Cardiology
UK Guidelines Supporting This Tool
UK Clinical Guidelines
GEPEG
NHS GGC — Current
Glasgow Emergency Paediatric ECG Guideline
Directly supports this dual interpretation model. Combines electronic report with manual checklist and defines ED disposition pathway for children.
APLS
ALSG 7th ed., 2023
Advanced Paediatric Life Support
Source for age-specific heart rate normal ranges used in the Rate step of this tool. Edited by Stephanie Smith, published Wiley-Blackwell, July 2023.
BJA Ed.
2020
How to Interpret an ECG in Children
Supports the sequential structured approach — Rate, Rhythm, Axis, Intervals, Morphology — used in this checklist.
Heart 2005
Dickinson, Leeds
The Normal ECG in Childhood and Adolescence
UK reference for paediatric ECG normal values. Defines QTc, PR, QRS, and T-wave limits by age group.
Normal Values Reference
Normal Values by Parameter
QTc
Less than 460 ms at all ages · QTc = QT ÷ √RR (Bazett) · If syncope present: >450 ms = red flag (GEPEG)
PR interval
3–5 small boxes (120–200 ms) · <3 boxes = check for WPW · >5 boxes = 1st degree heart block
QRS duration
Less than 3 small boxes (<120 ms) · Normal widens with age: neonates ~70–85 ms, adolescents up to ~110 ms
Q-waves
Depth <5 mm (children over 3 yrs) · Width <1 small box (<40 ms) in all leads
ST elevation
Less than 2 small boxes if present
Sources: GEPEG (NHS GGC, last reviewed Aug 2025) · GOS/Evelina London ECG Proforma v4.1 (Sep 2025) · Lambrechts & Fourie, BJA Education 2020 · Rijnbeek et al. Paediatric Normal ECG Study · Dickinson, Heart 2005 · APLS 7th ed. 2023
Clinical Pearl
"A normal-looking patient can still be critically unwell."
Dr Joshua Igwe · FRCEM