title: New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachycardia.
abstract: 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 (v(i)/v(t)), the vertical excursion (in millivolts) recorded during the initial (v(i)) and terminal (v(t)) 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, v(i)/v(t) >1 suggested SVT, and v(i)/v(t) < or =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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: 3rd Department of Medicine, Semmelweis University, School of Medicine, Budapest, Hungary. vereckei@kut.sote.hu
authors.forename: András
authors.initials: A
authors.lastname: Vereckei
authors.forename: Gábor
authors.initials: G
authors.lastname: Duray
authors.forename: Gábor
authors.initials: G
authors.lastname: Szénási
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Altemose
authors.forename: John M
authors.initials: JM
authors.lastname: Miller
mesh_terms: D000328:Adult; D000465:Algorithms; D053840:Brugada Syndrome / Q000503:physiopathology; D003937:Diagnosis, Differential; D004562:Electrocardiography; D004566:Electrodes; D005260:Female; D006801:Humans; D008297:Male; D013617:Tachycardia, Supraventricular / Q000175:diagnosis* / Q000503:physiopathology; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000503:physiopathology