eh-vee-arrr

The Case.

A 38 year old male presents to your ED with left sided chest heaviness which radiates to his left shoulder & down the arm. He has associated dyspnoea, nausea & vomiting. He looks unwell.

He underwent a CT-Coronary Angiogram 4 months earlier showing a Calcium-Score of 450 !! (‘Extensive plaque burden’. 8x increase in Framingham predicted risk). However, a Sestamibi study performed at the same time showed no evidence of inducible ischaemia.

This is his ECG…

38yo ECG01

What’s your interpretation ?
Is it significant ??
Where do you go from here ???

my take…

  • Sinus tachycardia at ~ 100bpm.
  • Normal axis. Normal intervals.
  • ~1.5mm STE in aVR, with widespread ST depression (V2-5, II, III, aVF).
  • DDx. Left main ischaemia vs triple vessel disease !!

He was treated aggressively with aspirin, GTN infusion & heparin.
I elected to withhold clopidogrel (a decision backed by Cardiology).

As his pain settled the following ECGs are taken…

38yo ECG02  38yo ECG03

For me this case was all about…..

aVR

The right-ward facing unipolar lead.

Obtains information about the right, upper side of the heart including the right ventricular outflow tract and basal septum.

Why is it important ??

Toxicology (particularly Na-channel blockade), dysrhythmias (P-wave configuration, identification of AV dissociation etc.) & ischaemic chest pain ….

In the setting of cardiac ischaemia, ST-segment elevation in aVR can indicate left main coronary artery stenosis.

      • Significant mortality (~70%)
      • Medical therapy not helpful –> patients need cardiac catheterisation
      • Other ECG features:
          • Concurrent STE in aVL
          • STE in aVR > STE in V1.
      • The greater the ST-elevation, the greater the mortality !!

It may also indicate proximal LAD occlusion or triple-vessel disease.

A recent post by Dr Smith on aVR has bought to my attention this important paper…

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

This study demonstrates that  ST-segment elevation >1 mm in lead aVR and positive troponin on admission are highly suggestive of severe LMCA or triple vessel disease (the converse is also true). The negative predictive value of STE > 1mm in aVR was 98% !! The authors (as well as Dr Smith) suggest that with the subsequent increased need for CABG, these patients would benefit from withholding clopidogrel (reducing the risk of intra-operative bleeding).

The Follow-up.

  • Patient is transferred pain-free to Coronary Care on GTN & Heparin infusions.
  • HS-Troponins 8 –> 12 –> 24 (Normal < 5).
  • The following morning he has an angiogram demonstrated significant 3-vessel disease.

He is now awaiting bypass-grafts….

References.

  1. Gorgels AP, Engelen DJ, Wellens HJ. Lead aVR, a mostly ignored but very valuable lead in clinical electrocardiography. J Am Coll Cardiol. 2001 Nov 1;38(5):1355-6.
  2. Kosuge M 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
  3. Dr. Smith’s ECG Blog: ST elevation in aVR, with widespread ST depression
  4. Life in the Fast Lane: Another Widow Maker.
  5. EMRAPTV Episode 68: aVR – Gets No Respect!

3 thoughts on “eh-vee-arrr

  1. Hi Chris,

    Excellent post highlighting the importance of looking at all of the 12 leads.

    Aside from toxicology and ischemia aVR is also useful in picking up lead reversals, particularly LA/RA reversal. When faced with an abnormal axis I always check whether incorrect lead positioning may be the culprit.

    A paper I really like is ‘aVR – The Forgotten Lead’ by George et. al, which can be found here (PubMed) or here (full text).

    Thanks,

    John L

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