Comparison of electrocardiogram aVR QRS metrics, as indices of the sums of leads I and II, and all 6 limb leads.

Electrocardiogram (ECG) peak-to peak amplitude (Pk-pk) of the limb leads, in the form of sums of leads I and II (I+II), or all 6 limb leads (Σ6Lblds), and lead aVR have been employed for the monitoring of patients with edematous states (ES), including heart failure (HF), or those undergoing hemodialysis (HD). The aim of this study was to compare aVR metrics (net QRS area [NQRSA], total QRS area [TQRSA], Pk-pk, and QRS root mean square [QRSRMS]) as indices of the corresponding metrics of I+II and Σ6Lblds. Automated measurements of the above metrics deriving from a set of randomly selected 1784 ECGs were compared and inter-correlated. NQRSA of aVR showed the best correlation with I+II (r=-0.99) and Σ6Lblds (r=-0.78), while Pk-pk the worst (r=0.68) and (r=0.62), correspondingly. NQRSA of aVR has advantages over Pk-pk, reflecting I+II or Σ6Lblds, and thus it might be employed in serial ECGs for the monitoring of patients with ES, including HF, and HD. However the present paper constitutes a methodological work, and thus the performance of NQRSA of aVR in monitoring patients with ES needs to be substantiated by a future study. Automated measurements of NQRSA of aVR are provided by many contemporary electrocardiographs upon recording of the ECG and could be put to use at the "point of care".