Wednesday, 15 February 2012

ECG of Week - 13th Feb 2012 - Interpretation

We had two ECGs this week from the same patient.


ECG 1 - with chest pain

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Rate:  
  • 102
Rhythm:  
  • Sinus
Axis:  
  • LAD (-30 to -60)
Intervals:  
  • PR – Prolonged (200 - 240ms)
  • QRS - Normal (80ms) 
  • QT - 440ms (QTc Bazette 310ms)
Segments 
  • ST Elevation aVR (3-4 mm) V1 (3mm) V2 (2mm) 
  • ST Depression I, II, aVF, aVL, V4-6
Additional:  
  • Notched p wave in lead II, possible biphasic P wave in V1
  • Poor r wave progression

Interpretation:
  • Most marked abnormality is ST elevation in aVR, V1-2, with ST Depression I, II, aVF, aVL, V4-6
  • Also 1st Degree AV block and possible left atrialenlargement (p mitrale)

  • This pattern is most consistent with a LMCA occlusion (STE aVR >/= V1) 
  • LMCA occlusion associated with a high mortality (aVR STE>1.5mm up to 70% mortality)
  • Could also be proximal LAD lesion or severe 3-vessel disease


Management
  • Urgent liaison with cardiology is required
  • Need to discuss reperfusion therapy based on available resources / local policies
  • Consideration of likelihood of requiring CABG is needed as this may affect initial drug therapy, particularly clopidogrel or prasugrel due to increased incidence of post operative bleeding

ECG 2 - Pain free post transfer

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Key features:
  • ST Elevation V1-2 (1mm)
  • ST Depression I, aVL, V5-6

Interpretation:
  • ST Elevation & Depression Resolving when compared with ECG 1

What happened next ?
  • Patient was reviewed and admitted by cardiology team
  • Planned for urgent angiography
  • Pt declined intervention
  • Re-presented with APO and cardiogenic shock

References / Further Reading

Life in the Fast Lane
  • ST Elevation in aVR here
  • More case reviews of STE in aVR here & here
  • Left Atrial Enlargement here 
Dr Smith's ECG Blog
Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.
Articles
  • Yamaji H, Iwasaki K, Kusachi S, Murakami T, Hirami R, Hamamoto H, Hina K, Kita T, Sakakibara N, Tsuji T. Prediction of acute left main coronary artery obstruction by 12-lead electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in lead V(1). J Am Coll Cardiol. 2001 Nov 1;38(5):1348-54. PMID: 11691506 Full text
  • Kosuge M, Ebina T, Hibi K, Morita S, Endo M, Maejima N, et al. An early and simple predictor of severe left main and/or three-vessel disease in patients with non-ST-segment elevation acute coronary syndrome. Am J Cardiol. 2011 Feb 15;107(4):495-500 PMID: 21184992