What EKG changes can facilitate differentiation between ventricular tachycardia (VT) and supraventricular tachycardia (SVT)?

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.)

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About Amy

Clinical Informationist at EUH Branch Library
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