ECG of the Week - 16th October 2017 - Interpretation

The following ECG is from a 23 yr old female who presents to the Emergency Department with lower limb cellulitis. A 'routine' ECG was performed.

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Rate:

• 66 bpm

Rhythm:

• Regular
• Sinus rhythm

Axis:

• Inferior

Intervals:

• PR - Short (~120ms)
• QRS - Prolonged (130ms)

Additional:

• Delta waves
• Best seen leads II, III, aVF, V2-6
• Deep Q wave in lead aVL
• 'Pseudo-infarction' pattern - secondary to pre-excitation rather than actual prior infarction
• ST depression and prominent R waves in leads V2-5
• RsR' pattern lead V1
• Reflecting change secondary to pre-excitation rather than actual RV hypertrophy or 'strain'

Interpretation:

• Wolff-Parkinson-White Syndrome / Pre-excitation
• Type A / Left-sided AP pattern
• Accessory pathway is located left lateral / anterolateral using Arruda algorithm

What should you do ?

You must inform the patient of the ECG findings and establish if there have been an symptoms of concern including:

• Syncope
• Palpitations / Arrhythmia
• Family history of Sudden Cardiac Death (SCD)
• Presence of known structural cardiac disease

In the absence of these features the patient does not require urgent cardiology input but can be referred as an out-patient for review. Long-term considerations including further investigation such as stress testing (to assess the response to exercise), echo (to assess for presence of structural disease) and EP study. Management options include observational follow-up only, drug therapy or RF ablation.

References / Further Reading

Life in the Fast Lane

• WPW / Pre-excitation

Textbook

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