Saturday, 14 March 2015

ECG of the Week - 9th March 2015 - Interpretation

This ECG is from a 70 yr old female who was referred into the Emergency Department with a 1 week history of abdominal pain and altered bowel habit. An out-patient CT scan showed diverticulitis complicated by local perforation. 
She had a past medical history of IHD (CABG and stents), hypertension and type 2 diabetes. During her initial assessment she complained of chest pain which lasted approximately 5 minutes and resolved spontaneously. 
The first of the ECG's below was taken during the episode of chest pain with the second performed ~ 5 minutes later once the patient was pain free.
Check out the comments on our original post here.


ECG 1
Patient complained of chest pain
Click to enlarge
Rate:
  • 96 bpm
Rhythm:
  • Regular
  • Sinus rhythm
Axis:
  • Normal
Intervals:
  • PR - Prolonged (~220ms)
  • QRS - Normal (100ms)
  • QT - 280ms (QTc Bazette 380 ms)
Segments:

  • ST Elevation lead aVR (~1.5mm)
  • ST Depression leads I, II, aVF, V3-6

Additional:

  • T wave inversion leads I, II, III, aVF, V3-6
  • Flat T wave lead aVL

Interpretation:

Diffuse ST segment change with elevation in aVR in the setting of chest pain 
Not a traditional STEMI but should prompt major concern for severe left main or LAD stenosis. However It is not specific for this and can be send with sub-endocardial ischaemia or severe triple vessel disease.In this patient with a known intra-abdominal perforation the differentials include both sub-endocardial demand ischaemia from concurrent illness but given the history of known IHD could also indicate active ACS.

ECG 2
Patient now pain free
Click to enlarge
Rate:
  • 72 bpm
Rhythm:
  • Regular
  • Sinus rhythm
  • Single PVC (Complex #2)
Axis:
  • Normal
Intervals:
  • PR - Prolonged (~220ms)
  • QRS - Normal (100ms)
  • QT - 380ms (QTc Bazette 415 ms)
Segments:
  • ST Elevation lead aVR - subtle and significantly less than ECG a
  • ST Depression leads I, II, aVF, V3-6  - subtle and significantly less than ECG a
Additional:

  • Flat T wave lead aVL

Interpretation:

  • Dynamic ST / T-wave changes improved compared with previous ECG

What happened ?

On discussion with the patient it became apparent they's been having unstable angina symptoms for several weeks. A prior angiogram from 18 months previous showed a left main severe distal stenosis (90%) with patent stents and vein grafts.
We got an urgent surgical and cardiological opinion as the combination of ACS and intra-abdominal perforation posed a significant management challenge. The patient received urgent broad-spectrum antibiotic cover and was commenced on heparin with single anti-platelet therapy due to the potential need for surgical intervention. Unfortunately the patient failed conservative treatment with worsening abdominal pain and underwent a laparotomy / washout / resection but suffered a post-procedural cardiac arrest.

References / Further Reading

Life in the Fast Lane

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