ECG Guide: Pediatrics

ECG Standard

  • Full standard: no adjustment
  • Half-standard: commensurate reduction in amplitude (usually 50%)
  • Mixed: reduction in amplitude of precordial leads

Atrial Abnormalities

Right Atrial Abnormality (P pulmonale)
Peaked P-wave in II (>3mm from 0-6mo or >2.5mm >6mo)
Causes: right atrial volume overload, ASD, Ebstein, Fontan
Left Atrial Abnormality (P mitrale)
Wide, notched P-wave in II or biphasic in V1
Causes: MS, MR


  • Anatomical dominance of right ventricle until approximately 6mo
  • RAD normal
  • eRAD suggests AV canal defect


  • 1st week of life: Upright
  • Adolescent: Inverted
  • Adult: Upright

Ventricular Hypertrophy

Right Ventricular Hypertrophy
R-wave height >98% for age in lead V1
S-wave depth >98% for age in lead V6
T-wave abnormality (ex. upright in childhood)
Causes: pHTN, PS, ToF
Left Ventricular Hypertrophy
R-wave height >98% for age in lead V6
S-wave depth >98% for age in lead V1
Adult-pattern R-wave progression in newborn (no large R-waves and small S-waves in right precordial leads)
Left-axis deviation
Causes: AS, coarctation, VSD, PDA


Normal Neonatal ECG

  • 2mo old
  • RAD
  • Inverted T-waves (normal)
  • Tall R-waves in V1-V3

Extreme Axis Deviation

  • Neonate with Down syndrome
  • Isoelectric in I, Negative in aVF negative in II  mean QRS vector -87°
  • Extreme RAD suggestive of AV canal defect


  • Unrepaired Coarctation
  • Deep S-wave in V1 (>98%)
  • Tall R-wave in V6 (>98%)


  • 10 year-old boy with pulmonary Hypertension
  • RAD after expected age for normal RAD
  • Tall R-waves in V1 (>98%)
  • Deep S-wave in V6 (>98%)


  • ALCAPA (anomalous origin of the left coronary artery from the pulmonary artery): coronary artery arises anomalously from the pulmonary artery; as pulmonary arterial pressure falls during the first 6 months of infancy, prograde flow through the left coronary artery ceases and may even reverse.
  • HLHS (hypoplastic left heart syndrome): coronary arteries are perfused from a hypoplastic, narrow aorta that is susceptible to flow disruption
  • Orthotopic heart transplant with allograft vasculopathy
  • Kawasaki: coronary artery aneurysm with subsequent thrombosis

Benign early repolarization

  • 14 year-old male
  • Concave ST-segment elevation

Left Atrial Abnormality:

  • 9mo female with mitral insufficiency
  • Broad biphasic P-wave in V1
  • Tall, notched P-wave in II

Prolonged QT interval

  • 18-year-old female
  • Familial long QT syndrome and a history of cardiac arrest


  • Delta wave, shortened PR interval


  1. O’Connor M, McDaniel N, Brady WJ. The pediatric electrocardiogram. Part I: Age-related interpretation. Am J Emerg Med. 2008;26(2):221-228. doi:10.1016/j.ajem.2007.08.003.
  2. Goodacre S, McLeod K. ABC of clinical electrocardiography: Paediatric electrocardiography. BMJ. 2002;324(7350):1382-1385.
  3. O’Connor M, McDaniel N, Brady WJ. The pediatric electrocardiogram Part II: Dysrhythmias. Am J Emerg Med. 2008;26(3):348-358. doi:10.1016/j.ajem.2007.07.034.
  4. O’Connor M, McDaniel N, Brady WJ. The pediatric electrocardiogram Part III: Congenital heart disease and other cardiac syndromes. Am J Emerg Med. 2008;26(4):497-503. doi:10.1016/j.ajem.2007.08.004.
  5. Schwartz P. Guidelines for the interpretation of the neonatal electrocardiogram. Eur Heart J. 2002;23(17):1329-1344. doi:10.1053/euhj.2002.3274.