ECG of the Week - 18th July 2016 - Interpretation

The following ECG is from a 28 yr old female who is 20 weeks pregnant. She presented complaining of dysponea and chest pain.

Click to enlarge

Rate:

• 72 bpm

Rhythm:

• Regular
• Sinus rhythm

Axis:

• Normal (-33 deg)

Intervals:

• PR - Short (80ms)
• QRS - Prolonged (120ms)
• QT - 400ms (QTc Bazette 380-400 ms)

Segments:

• Nil significant changes

Additional:

• Delta waves leads I, aVL
• Deep Q wave leads III, aVF
• T wave inversion leads aVL, V1, V2, aVR
• Voltage criteria LVH
• R wave aVL >11mm

Interpretation:

• Pre-excitation (WPW)
• Deep Q waves in inferior leads mimic old inferior MI referred to as pseudo-infarction pattern this is due to pre-excitation and does not reflect prior ischaemia.
• AP location is postero-septal tricuspid annulus using Arruda algorithm

What happened ?

The patient had known WPW, it would spoil the fun if I told you that in advance. She was investigated from a possible PE which was negative and discharged.

References / Further Reading

Life in the Fast Lane

• Pre-excitation Syndromes

Textbook

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