ECG of the Week - 22nd August 2016 - Interpretation

This ECG is from a 20 yr old female who presented following an episode of palpitations with associated chest pain and dysponea.

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Rate:

• 60

Rhythm:

• Sinus arrhythmia

Axis:

• Normal

Intervals:

• PR - Short (~100ms)
• QRS - Prolonged (120-130ms)
• QT - 440ms (QTc Bazette 440 ms)

Segments:

• ST elevation leads III, aVF <1mm with flat morphology

Additional:

• Delta waves leads I, V1-4
• Pseudo right ventricular hypertrophy secondary to pre-excitation rather than actual chamber enlargement with the following ECG features:
• Dominant R wave leads V1-6
• R/S ratio >1 in lead V1
• T wave inversion leads aVL, V1-3

Interpretation:

• Wolff-Parkinson-White Syndrome
• Left posterior / left posterolateral accessory pathway using Arruda algorithm

What happened ?

The patient had known pre-excitation and had been non-compliant with beta-blocker and sodium-channel blocker therapy. The patient was admitted for telemetry and re-instigation of anti-arrhythmic agents prior to ablation consideration / planning.

References / Further Reading

Life in the Fast Lane

• Pre-excitation Syndromes
• Right ventricular hypertrophy

Textbook

• Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.