Vereckei A, et al. New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachycardia. Heart Rhythm. 2008; 5(1): 89-98.
Describes algorithm of EKG changes observed in the aVR lead, including presence of initial R wave, presence of initial r or q wave > 40 ms, presence of a notch on descending limb of a negative onset and predominantly negative QRS, and ratio of the slopes of the initial 40 ms of QRS/terminal 40 ms of QRS.
Prospective study of 483 wide QRS complex EKGs (351 VTs, 112 SVTs, 20 pre-excited tachycardias) from 313 consecutive patients. Blinded to the electrophysiologic diagnosis and clinical findings, two authors analyzed the EKGs using the algorithm. See Fig 1 (p. 91) for the algorithm, as well as Brugada. Applying the new aVR lead criteria led to an accurate diagnosis in 91.5% EKGs. To see accuracy of individual criteria, as well as comparison to Brugada algorithm, see Table 2 (p. 95.)