Title: New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachycardia
BACKGROUND:
We recently reported an ECG algorithm for differential diagnosis of regular wide QRS complex tachycardias that was superior to the Brugada algorithm.
OBJECTIVE:
The purpose of this study was to further simplify the algorithm by omitting the complicated morphologic criteria and restricting the analysis to lead aVR.
METHODS:
In this study, 483 wide QRS complex tachycardias [351 ventricular tachycardias (VTs), 112 supraventricular tachycardias (SVTs), 20 preexcited tachycardias] from 313 patients with proven diagnoses were prospectively analyzed by two of the authors blinded to the diagnosis. Lead aVR was analyzed for (1) presence of an initial R wave, (2) width of an initial r or q wave 40 ms, (3) notching on the initial downstroke of a predominantly negative QRS complex, and (4) ventricular activation-velocity ratio (vi/vt),the vertical excursion (in millivolts) recorded during the initial (vi) and terminal (vt) 40 ms of the QRS complex. When any of criteria 1 to 3 was present, VT was diagnosed; when absent, the next criterion was analyzed. In step 4, vi/vt 1 suggested SVT, and vi/vt 1 suggested VT.
RESULTS:
The accuracy of the new aVR algorithm and our previous algorithm was superior to that of the Brugada algorithm (P .002 and P .007, respectively). The aVR algorithm and our previous algorithm had greater sensitivity (P .001 and P .001, respectively) and negative predictive value for diagnosing VT and greater specificity (P .001 and P .001, respectively) and positive predictive value for diagnosing SVT compared with the Brugada criteria.
CONCLUSION :
The simplified aVR algorithm classified wide QRS complex tachycardias with the same accuracy as standard criteria and our previous algorithm and was superior to the Brugada algorithm.
