Wednesday, 10 October 2012

ECG of the Week - 8th October 2012 - Interpretation

This ECG is from a 62 year old.
Presents with cough, fever, and recent diagnosis of pneumonia.
An ECG taken 2 weeks previous has been documented as normal, unfortunately the original ECG is not available for comparison.





Click to enlarge

Rate:
  • 84
Rhythm:
  • Regular (complexes 1-3, 7-14)
  • Irregular (complexes 4 - 6)
  • No 1:1 P:QRS relationship

Axis:
  • Normal (45 deg)
Intervals:
  • PR - Nil visible
  • QRS - Normal (80ms)
  • QT - 320ms (QTc Bazette ~ 380 ms)
Segments:

  • V1-2 high take off
Additional:

  • Nil clear p waves visible ? retrograde p visible in V4-6
  • ? p wave preceding 6th complex, complicated by artifact
  • Biphasic T waves II, III, aVF, V2-3
  • T Inversion V4-6
  • Positive T wave aVR
Interpretation:


  • Junctional rhythm ? sinus capture 6th complex
  • Longer rhythm strip would be helpful to differentiate junctional from other arrhythmia
  • Biphasic T waves in V2-3 suggest Wellen's - ? unmasked by hyperdynamic state
  • Diffuse infero-lateral T inversion? ischaemia, electrolyte disturbance, myocarditis

The patients troponin was also elevated at 0.37 [normal <0.05]. 

I've searched our database to try and locate the patient that this ECG belongs to with no success as I'd like to get some closure on this one, but no luck unfortunately.

Thanks to everyone who commented on this ECG, it made me do some reading around some of the thoughts and suggestions. We'd certainly agree with the differentials of Wellen's, peri/myocarditis, or ischaemia.

Dave B suggested Benign T Wave Inversion (BTWI) in the differential.
Dr Smith has an excellent post covering BTWI here. The presence of a 'normal' ECG 2 weeks prior to this presentation I think makes BTWI unlikely as I would of hoped someone would have noticed the T wave changes. Dr Smith does have an ECG example on his post which was dynamic in nature, but this was from a young black male with serially negative cardiac enzymes.

As an aside note there is some evidence suggesting positive T wave in aVR following an anterior AMI is a marker of increased mortality and poor cardiac function, reference below.

References / Further Reading

Life in the Fast Lane

  • Wellen's Syndrome here
Dr Smith's ECG Blog
  • Benign T Wave Inversion here
Papers
  • Shinozaki K, Tamura A, Kadota JAssociations of positive T wave in lead aVR with hemodynamic, coronary, and left ventricular angiographic findings in anterior wall old myocardial infarction. J Cardiol. 2011 Mar;57(2):160-4. PMID: 21316193
  • Roukoz H, Wang K. ST elevation and inverted T wave as another normal variant mimicking acute myocardial infarction: the prevalence, age, gender, and racial distribution. Ann Noninvasive Electrocardiol. 2011 Jan;16(1):64-9. PMID: 21251136
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Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.