Wednesday, 23 October 2013

ECG of the Week - 21st October 2013 - Interpretation

This week case includes three ECG's from the same patient.
They are from a 74 yr old patient who I assume had multiple medical co-morbidities.
The patient presented having had several episodes of chest pain in the preceding 24 hours.
Check out our comments from the original case post here.

ECG 1

This first ECG was taken on arrival to the Emergency Department with the patient pain free.


ECG 1 - Pain free on presentation
Rate:
  • 66
Rhythm:
  • Regular
  • Sinus rhythm
Axis:
  • Borderline LAD (~ -30 deg)
Intervals:
  • PR - Normal (~180ms)
  • QRS - Normal (80ms)
  • QT - 400ms (QTc Bazette ~ 420 ms)
Segments:

  • Minor ST depression lead III

Additional:

  • T wave inversion leads II, III, aVF, V4, V5, V6
  • Biphasic T wave leads aVR, V3
  • Early precordial transition between V1 and V2
    • Dominant R wave V2
  • Prominent T wave lead V2


ECG 2

The patient then developed chest pain and the following ECG was recorded.


ECG 2- Taken during an episode of chest pain
Rate:
  • 84
Rhythm:
  • Regular
  • Sinus rhythm
Axis:
  • Normal (~20 deg)
Intervals:
  • PR - Normal (~200ms)
  • QRS - Normal (80ms)
  • QT - 360ms (QTc Bazette ~ 415 ms)
Segments:

  • ST Elevation leads II (2mm), III (3mm), aVF (2mm), V4 (1.5mm), V5 (1mm), V6 (1mm)
  • ST Depression aVR, aVL, V1, V2
    • Note horizontal ST morphology in V2

Additional:

  • Pseudo-normalisation of T waves leads II, III, aVF, V4, V5, V6
  • Early precordial transition between V1 and V2
    • Dominant R wave V2
  • Prominent T wave lead V2

ECG 3

The episode of pain lasted only several minutes and resolved spontaneously.
The ECG below was taken 8 minutes after the second ECG with the patient now pain free. 


ECG 3 - Patient pain free, taken 8 minutes following ECG 2
Rate:
  • 66
Rhythm:
  • Regular
  • Sinus rhythm
Axis:
  • Borderline LAD (~ -30 deg)
Intervals:
  • PR - Normal (~180ms)
  • QRS - Normal (80ms)
  • QT - 380ms (QTc Bazette ~ 410 ms)
Segments:

  • ST elevation leads III, aVF
    • Reduced compered with ECG 2

Additional:




  • T wave inversion leads II, III, aVF, V4, V5, V6
  • Early precordial transition between V1 and V2
    • Dominant R wave V2
  • Prominent T wave lead V2
Interpretation

ECG series showing ischaemia with re-perfusion (ECG 1), subsequent re-occlusion (ECG 2) with infero-postero-lateral STEMI, and spontaneous re-perfusion (ECG 3).

What happened ?

The patient was immediately discussed with cardiology services. Treated with aspirin, clopidogrel, and placed on a heparin infusion and admitted to CCU. The patient remained pain free, troponin peaked at 12 hours, 4.8 (normal <0.05), and the patient was transfer the next day for angiography. 
The angio showed:

  • Right coronary: 98% stenosis --> stented
  • Circumflex: 80% stenosis
  • Left anterior descending: 80% proximal stenosis
  • Left main: 20% proximal stenosis
  • Left ventricle: Inferior hypokinesis with normal LV function

I'd recommend having a look at Dr Smith's ECG blog, links below, for some more great examples of re-perfusion / re-occlusion ECGs.

References / Further Reading
Dr Smith's ECG blog



Life in the Fast Lane

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