avr

Augmented leads (aVR, aVF, and aVL) were developed to derive more localized information looking at the right, lower, and left part of the heart respectively.  Specifically, lead aVR obtains information from the right upper side of the heart.  It also gives reciprocal information on the left lateral side of the heart, which is already covered by leads aVL, I, II, V5, and V6.  This is the main reason lead aVR has become forgotten.

ECG - E tri and Cardiac Axis

What is the sensitivity and specificity of lead aVR for left main coronary artery (LMCA) occlusion?

aVR findingSensitivitySpecificity
aVR ST elevation (>0.05 mV) greater than
V1 ST elevation 1
81%80%
aVR ST elevation (>0.05 mV) 2 68.2%73.3%
aVR ST elevation (>0.05 mV) 3 91%79%
aVR ST elevation (>0.1 mV) 3 80%93%
aVR ST elevation (>0.15mV) 3 27%98%

Conclusion: ST elevation >0.05 mV in aVR has a SENSITIVITY 68-91% and SPECIFICITY 73-80%.

Does ST elevation in lead aVR predict clinical outcome?

  • ST elevation of aVR (0.15 mV) predicts death with 75% sensitivity and 75% specificity 1
  • ST elevation of aVR (0.05 – 0.1 mV) associated with death 8.6%
  • ST elevation of aVR (>0.1 mV) associated with death 19.4% (1.3% with no aVR ST elevation) 4
  • MORTALITY in ST elevation of aVR (0.05 mV) 30.2% vs no ST elevation in aVR 12.2% 5

Conclusion: ST elevation in lead aVR has INCREASED MORTALITY versus no ST elevation in lead aVR.

What is the best management of ST elevation in lead aVR?

  • Several studies quote a 3-year mortality rate of 50% for medical management and 36% for PCI, stating that surgery (CABG) is the treatment of choice.
  • There are several new studies now looking at drug eluding stents (DES) as an option:

avr table

  • Currently the EXCEL (Evaluation of Xience Prime versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial is underway and recruiting patients and can hopefully give us a more clear answer.

Conclusion: It is still not clear who would be best treated with PCI versus CABG in LMCA occlusion.

Final Thoughts

Lead aVR is a forgotten but valuable lead that is highly predictive of LMCA occlusion and gives prognostic information. The best management of LMCA occlusion is still unclear (PCI vs CABG).

Additional Reading

  1. Chieffo A et al. 5-Year Outcomes Following Percutaneous Coronary Intervention With Drug-Eluting Stent Implantation Versus Coronary Artery Bypass Graft for Unprotected Left Main Coronary Artery Lesions: The Milan Experience. JACC Cardiovas Interv 2010 June; 3 (6): 595 – 601. PMID: 20630452
  2. Nakamura K et al. Significance of ST-Segment Elevation in Lead aVR. Arch Intern Med 2012 Mar; 172 (5): 389. PMID: 22412103 
  3. PV Card on 5 things to consider in an abnormal aVR lead

Images 13

1.
Yamaji H, Iwasaki K, Kusachi S, et al. 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;38(5):1348-1354. [PubMed]
2.
Rostoff P, Piwowarska W. ST segment elevation in lead aVR and coronary artery lesions in patients with acute coronary syndrome. Kardiol Pol. 2006;64(1):8-14; discussion 15. [PubMed]
3.
Kosuge M, Ebina T, Hibi K, 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;107(4):495-500. [PubMed]
4.
Barrabés J, 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;108(7):814-819. [PubMed]
5.
Abbase AH, ALjubawii AA. The Significance of ST Segment Elevation in Lead aVR in Acute Anterior Myocardial Infarction. Medical Journal of Babylon. 2011;8(4):490-496. http://www.iasj.net/iasj?func=fulltext&aId=32167. [Source]
Salim Rezaie, MD

Salim Rezaie, MD

ALiEM Associate Editor Clinical Assistant Professor of EM and IM University of Texas Health Science Center at San Antonio Founder, Editor, Author of R.E.B.E.L. EM and REBEL Reviews
Salim Rezaie, MD

@srrezaie

EM/IM Doc; Founder of REBEL EM & REBEL Cast; Doing my Part to Cut Down on KT Time; Viva #FOAMed #FOAMcc (Tweets are opinion only)