ECG of the Week - 15th February 2016 - Interpretation

The following ECG is from an 86 yr old female who presented following an episode of chest pain. She has a dual chamber PPM in situ following a prior episode of complete heart block. Old ECG's revealed an A-paced rhythm with no lateral / high lateral T wave inversion.

Click to enlarge

Rate:

• 60 bpm

Rhythm:

• Regular
• A-paced rhythm
• Atrial pacing spike with subsequent atrial depolarisation p wave
• QRS Complexes conducted in native pattern via AV node

Axis:

• Normal

Intervals:

• PR - Normal (~200ms)
• QRS - Normal (100ms)
• QT - 440ms (QTc Bazette 440 ms)

Segments:

• ST Elevation <1mm lead aVR
• ST Depression leads II, V4-6

 Additional:

• Biphasic T wave lead V3
• T wave inversion leads I, aVL, V4-6
• Borderline LVH by voltage criteria

Interpretation:

• ST Segment changes in lateral / high lateral leads

Differentials

• ACS 
• Most likely given history of chest pain and new changes when compared with old ECG's
• T wave memory
• Potential for ST / T wave changes to be due to a period of V-paced rhythm
• We have covered T-wave memory before here and here
• Secondary to LVH
• Drug effects especially digoxin although not typical appearance

 What happened ?

The patient was admitted under the Rehab team and had a troponin raise, following discussion with cardiology the patient was deemed for medical management only.

References / Further Reading

Life in the Fast Lane

• Digoxin ECG effects 

Textbook

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