Clinical Value of Lead aVR

Abstract

Lead aVR is the only lead in the surface ECG that does not face the "typically" relevant walls of the left ventricle. Historically, its value has been neglected most likely due to its unusual configuration and direction, which appeared to have little correlation with other more congruous and easily diagnostic frontal leads. The isolation of the unipolar leads in the Standard surface ECG presentation may also have played an important role. Even with this "unfair" neglect, we know nowadays that it is very sensitive to locate obstructed epicardial coronary arteries. Besides helping distinguishing the culprit lesion of an infarct, lead aVR also helps recognizing other conditions that could be of clinical significance such as pericarditis, Brugada syndrome, fascicular blocks of the right branch, ectopic left atrial rhythms, etc. The purpose of this review is to revise the clinical value of lead aVR in the recognition of frequent and not so frequent clinical conditions.

Complete Absence of Precordial R Waves Due to Absence of Left‐Sided Pericardium

“…On a normal ECG, lead aVR records a negative QRS complex because its orientation is opposite to the direction of the electrical main vector 16 . Only a few causes for a positive QRS complex in lead aVR have been identified so far including Brugada syndrome, right ventricular overloading or acute intoxication with tricyclic antidepressants 15,17,18 . In our report, we documented for the first time that congenital absence of the pericardium represents another differential diagnosis of a prominent R wave in lead aVR which is explained by the abnormal intrathoracic heart position.…”

“…As aVR does not correspond to a specific myocardial territory and does not correlate with the other leads, its analysis is often somehow neglected. Nevertheless, there are several works documenting the clinical value of aVR abnormalities for different cardiac pathologies 15 . On a normal ECG, lead aVR records a negative QRS complex because its orientation is opposite to the direction of the electrical main vector 16 .…”

Why complicate an important task? An orderly display of the limb leads in the 12-lead electrocardiogram and its implications for recognition of acute coronary syndrome

“…Likely due to its different waveform morphology compared to the other limb leads, lead aVR is often ignored during ECG interpretation [14]. When 35 participants at an international scientific meeting on electrocardiography were asked to interpret 5 ECGs, the majority did not notice that aVR in all ECGs had been replaced by its inverted version [15].…”

“…When 35 participants at an international scientific meeting on electrocardiography were asked to interpret 5 ECGs, the majority did not notice that aVR in all ECGs had been replaced by its inverted version [15]. Following this report, the importance of including aVR in ECG interpretation has been highlighted in several papers [14, 16–22]. ST elevation and positive T waves in aVR have been found to carry independent prognostic information [23, 24].…”

Impact of T wave amplitude in lead aVR on predicting cardiac events in ischemic and nonischemic cardiomyopathy patients with an implantable cardioverter defibrillator

“…Although the lead aVR is often neglected in daily clinical practice, ST elevation in lead aVR has been reported to be useful in the prediction of left main trunk involvement in ischemic heart disease and aortic dissection (Kireyev, Arkhipov, Zador, Paris, & Boden, 2010;Riera et al, 2011;Yan et al, 2007). Similarly, there is an increasing notion that T wave amplitude in the lead aVR (TAaVR) >0 mV (known as upright T wave) may be used as a prognostic tool in patients with postmyocardial infarction, in those with renal failure who undergo hemodialysis, and in male patients (Jaroszyński et al, 2015;Tan, Engel, Myers, Sandri, & Froelicher, 2008;Torigoe et al, 2012).…”