ECG Exigency 014a
An ECG is taken on arrival and shown below:
His chest pain and his ST depression seem to settle with some GTN and morphine. You load him with Aspirin, Clopidogrel and Heparin and admit him under the cardiologists with a view to angiography in the next 24 hours. The junior cardiology registrar seems a bit overwhelmed but is delighted with your management so far and happily accepts the patient.
You arrive in work the next morning and the first thing the night team say is that phrase dreaded by Emergency Doctors the world over:
‘Do you remember that patient you saw last night…?’
Turns out he crashed and burned in the Coronary care unit and is now in ICU on an intraaortic balloon pump with a guarded prognosis…
The cardiologist storms into the ED and corners you yelling:
‘Didn’t you know ST elevation in aVR means left main coronary artery occlusion?’
Is he right? Could you or should you have done anything differently?
ST ELEVATION IN aVR.
LMCA Stenosis Predictor?
aVR is the forgotten ECG lead – some even suggest we should call it an 11 lead ECG. ST segment elevation in aVR is often ignored as just being a reciprocal change but does it mean more than that?
The answer is yes, but it probably isn’t as much of a direct correlate with LMCA stenosis as the cardiologist is stating. Some quote a specificity of 98% when ST elevation in aVR is also present in aVL. However this figure seems to be from several deeply flawed papers with small numbers of highly selected non-emergency patients.
The largest study on ST elevation in aVR found it was associated with LMCA stenosis when compared to patients with ACS without elevation, but nowhere near as strongly as previously suggested (14.7% of patients with ≥ 1mm vs 5.1% without). When LMCA stenosis was combined with 3 vessel disease into a composite endpoint (ie: the traditional indications for CABG) it performed substantially better – 55.9% vs 26.1. It’s a good indicator, but certainly not a done deal.
One study of 775 consecutive patients with NSTEMI found in hospital mortality was 1.3% in those without ST elevation in aVR, compared with 19.4% in those with ≥ 1mm ST elevation.
However a subsequent much larger (and possibly definitive study) of 5064 patients from the GRACE registry suggests a much less startling , but still substantial difference in mortality (4.2 % vs 7.9%. p<0.03).
- LMCA stenosis is bad – 70 % mortality without surgery / PTCA.
- ST Elevation of more than 1mm inaVR in the setting of Acute Coronary syndrome:
- is associated with left mainstem disease and 3 vessel disease
- suggests urgent angiography is necessary
- is associated with an increase in mortality.\
- probably not an indication for emergent angiography @ 3am unless the patient is not settling with standard medical therapy.
- Yan AT, Yan RT, Kennelly BM, Anderson FA Jr, Budaj A, et al.Relationship of ST elevation in lead aVR with angiographic findings and outcome in non–ST elevation acute coronary syndromes. Am Heart J. 2007 Jul;154(1):71-8. PMID: 17584554
- Kosuge M, Kimura K, Ishikawa T, Ebina T, et al. Combined prognostic utility of ST segment in lead aVR and troponin T on admission in non-ST-segment elevation acute coronary syndromes. Am J Cardiol. 2006 Feb 1;97(3):334-9. PMID: 16442391
- Kosuge M, Ebina T, Hibi K, Morita S, et al. Early, accurate, non-invasive predictors of left main or 3-vessel disease in patients with non-ST-segment elevation acute coronary syndrome. Circ J. 2009 Jun;73(6):1105-10. PMID: 19359810
- S Kurisu, I Inoue, T Kawagoe, M Ishihara, et al. Electrocardiographic features in patients with acute myocardial infarction associated with left main coronary artery occlusion. Heart. 2004 Sep;90(9):1059-60. PMID: 15310704
- Barrabés JA, Figueras J, Moure C, Cortadellas J, Soler-Soler J. Prognostic value of lead aVR in patients with a first non-ST-segment elevation acute myocardial infarction. Circulation. 2003 Aug 19;108(7):814-9. PMID: 12885742