ECG reference
Pediatric ECG basics.
Kids aren't small adults on the monitor. Here's what changes with age.
Normal heart rate by age
| Age | Awake HR (bpm) |
|---|---|
| Newborn (0–1 mo) | 100–170 |
| Infant (1–12 mo) | 100–160 |
| Toddler (1–3 yr) | 90–150 |
| Preschool (3–5 yr) | 80–140 |
| School age (5–12 yr) | 70–120 |
| Adolescent (12+ yr) | 60–100 |
Key age-based differences
- RV dominance at birth — right axis deviation is normal, tall R waves in V1.
- Axis shifts leftward over the first 6 months as LV mass grows.
- Juvenile T-wave pattern: T inversions in V1–V3 through adolescence.
- Shorter PR and QRS intervals than adults.
- Sinus arrhythmia (respiratory variation) is normal and often prominent.
Pediatric SVT vs sinus tach
| Sinus tach | SVT | |
|---|---|---|
| Infant HR | < 220 | > 220 |
| Child HR | < 180 | > 180 |
| P waves | Present, normal | Absent or abnormal |
| Variability | Beat-to-beat variability | Fixed rate |
| Onset | Gradual | Abrupt |
EMS pearl
Kids compensate with tachycardia long before dropping their BP. A cold, mottled toddler with HR 190 and "normal" BP is in shock. Trust HR trend and perfusion — not the cuff.
Frequently asked
- What is a normal pediatric heart rate?
- Newborn 100–170, infant (1–12 mo) 100–160, toddler 90–150, preschool 80–140, school age 70–120, adolescent 60–100 bpm awake.
- Why do neonates have right-axis deviation?
- In utero the right ventricle is dominant. RV dominance persists in newborns and slowly shifts to a normal adult leftward axis by about 6 months.
- Are inverted T waves in V1–V3 normal in children?
- Yes — the juvenile T-wave pattern (inverted T in V1–V3) is normal from infancy through adolescence and typically resolves by early adulthood.
- What is a normal pediatric QTc?
- QTc < 440 ms is generally normal. QTc > 460 ms in girls and > 450 ms in boys is prolonged. Correct using Bazett's formula.
More pediatric prep