Lead aVR

Author: Michelle Lin, MD
Updated: 11/18/2011

ECG: Lead aVR

Lead avR can provide some unique insight into 5 different conditions:

  1. Acute MI
  2. Pericarditis
  3. Tricyclic antidepressants (TCA) and TCA-like overdose
  4. AVRT in narrow complex tachycardias
  5. Differentiating VT from SVT with aberrancy in wide complex tachycardias

Acute myocardial infarction

ST Elevation >1.5 mm in aVR

Example of ST elevation

  • Suggests left main coronary artery (LMCA), left anterior descending (LAD), or 3-vessel coronary disease
  • LMCA occlusion has a high mortality and often refractory to thrombolytics.
  • aVR ST elevation in ACS patients: Independent predictor of recurrent ischemic events in-hospital, heart failure, and death

Pericarditis

PR elevation in aVR

Example of PR elevation

Suggests subepicardial atrial injury from pericardial inflammation

Multilead ST elevation:

  • Differential diagnosis includes ACS vs pericarditis
  • Concurrent PR elevation in aVR suggests pericarditis instead of ACS.

Tricyclic antidepressant (TCA) & TCA-like overdose

Prominent R wave in aVR

Example of a prominent R wave

  • Classic ECG findings of TCA overdose:
    • Sinus tachycardia
    • Widened QRS and QTc interval
    • Right axis deviation 130-170 degrees
    • Prominent terminal R wave in aVR
  • Predictor of arrhythmia (Buckley et al. Crit Care, 2003):
    • R/S ratio in aVR >0.7 (PPV 46%, NPV 95%)

AVRT in Wolff-Parkinson-White (WPW)

Atroventricular reentry tachycardia

  • ST elevation in aVR in narrow complex tachycardia
  • Narrow complex tachycardia ddx:
    • AV node reentry tachycardia
    • AV reentry tachycardia
    • Atrial tachycardia
  • ST elevation in aVR suggestive more of AVRT in WPW (sensitivity 71%, specificity 70%)

Vereckei criteria: VT versus SVT in wide complex tachycardia

Vereckei criteria:

  • Asks 4 questions.
  • More sensitive and specific to detect ventricular tachycardia (VT) than Brugada criteria.

  • Criteria looks ONLY at lead aVR (if answer is yes, then VT):

  • Is there an initial R wave?

  • Is there a r or q wave >40 msec? (>1 small box width)
  • Is there a notch on the descending limb of a negative QRS complex?
  • Measure the voltage change in the first (vi) and last 40 msec (vt). Is vi / vt <1?

Example of VT vs SVT

Criteria Sensitivity Specificity PPV NPV
Brugada 89% 73% 92% 67%
Verecki 97% 75% 93% 87%

(Vereckei et al, Heart Rhythm 2008)

References

  • Kireyev D et al.Clinical utility of aVR-The neglected electrocardiographic lead. Ann Noninvasive Electrocardiol. 2010;15(2):175-80. [PubMed]
  • Riera AR et al.Clinical value of lead aVR. Ann Noninvasive Electrocardiol. 2011 Jul;16(3):295-302. [PubMed]
  • Vereckei A, Duray G, Szénási G, Altemose GT, Miller JM. New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachycardia. Heart Rhythm. 2008 Jan;5(1):89-98. doi: 10.1016/j.hrthm.2007.09.020. Epub 2007 Sep 20. [PubMed]
  • Buckley NA et. al.The limited utility of electrocardiography variables used to predict arrhythmia in psychotropic drug overdose.Crit Care. 2003 Oct;7(5):R101-7. Epub 2003 Aug 18. [PubMed]
  • Williamson K et al. Electrocardiographic applications of lead aVR. Am J Emerg Med. 2006 Nov;24(7):864-74. [PubMed]