ECG of the Week - 9th February 2015 - Interpretation

This ECG is from a 1 yr old who was brought to the Emergency Department following a suspected nicotine ingestion. The child was clinically well and vital signs were within age appropriate ranges.
Check out the comments on our original post here.

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Rate:

• ~102 bpm

Rhythm:

• Sinus Arrythmia

Axis:

• Normal (40 deg)

Intervals:

• PR - Normal (120ms)
• QRS - Normal (60ms)
• QT - 300ms (QTc Bazette 390 ms)

Segments:

• Subtle J-point elevation in leads II, & aVF (<1mm)

Additional:

• Dominant R wave in leads V2-3
• rSr' Pattern in lead V1
• T wave inversion leads V1-3
• Normal paediatric T-wave pattern
• Prominent Q waves in leads II, III, aVF, V4-6
• Maximal in lead III at 9-10mm (0.9-1.0 mV)

Interpretation:

• No concerning toxicological features
• Normal paediatric features including:
• Heart Rate
• T-wave changes
• Right precordial QRS voltages & T wave changes
• Unusual feature:
• Q waves in the infero-lateral leads are normally seen
• The voltage of the Q wave in lead III is greater than the normal range as proposed by Davignon et al. & Taylor et al.
• However, Chou's suggests the Q wave amplitude may be up 14 mm !

Interpretation of the paediatric ECG is challenging given the variation of normal features when compared with the adult ECG. The inferior QRS voltages in this ECG would concern me, although they may reflect a normal variant - for this ECG I would be asking a paediatric cardiologist to have a look at it. I will try and get some more information on the case and canvas some opinions from my paediatric colleagues.

For a great overview of paediatric ECG changes check out the Life in the Fast Lane page below:

• Paediatric ECG

References / Further Reading

Textbook

• Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.
• Surawicz B, Knilans TK. Chou's Electocardiography in Clinical Practice, 6th Edition Saunders Elseiver 2008.