title: Specificity of the wide QRS complex tachycardia algorithms in recipients of cardiac resynchronization therapy.
abstract: BACKGROUND
  We assessed the specificity of wide QRS complex tachycardia (WCT) differentiating algorithms in patients with preexistent left bundle branch block (LBBB) and heart failure.
  
  
  METHODS
  Three hundred fourteen patients with resynchronization devices were retrospectively screened. electrocardiograms with supraventricular LBBB rhythm were used as a surrogate for supraventricular tachycardia QRS morphology. The Pava lead II criterion, ventricular activation velocity ratio (Vi/Vt) ratio in V(2), Vereckei aVR, Brugada, Griffith, and Bayesian algorithms were investigated.
  
  
  RESULTS
  The WCT algorithms had a lower specificity (33%-69%) in patients with LBBB than in general WCT populations. The Pava lead II criterion and Brugada algorithm had higher specificity than other algorithms (P < .05). Several of the single criteria (absence of an RS complex in V(1) through V(6), initial R wave in aVR, Vi/Vt < 1 in V(2)) had specificities of 92% to 99%.
  
  
  CONCLUSIONS
  In patients with heart failure and LBBB, an electrocardiographic diagnosis of ventricular tachycardia should be based on selected, specific criteria rather than on WCT algorithms.
authors: First Department of Cardiology and Hypertension, University Hospital, Cracow, Poland. mcjastrz@cyf-kr.edu.pl
authors: Marek
authors: M
authors: Jastrzebski
authors: Piotr
authors: P
authors: Kukla
authors: Danuta
authors: D
authors: Czarnecka
authors: Kalina
authors: K
authors: Kawecka-Jaszcz
mesh_terms: D000368:Aged; D000465:Algorithms; D002037:Bundle-Branch Block / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D058406:Cardiac Resynchronization Therapy / Q000706:statistics & numerical data*; D015897:Comorbidity; D004562:Electrocardiography / Q000379:methods / Q000706:statistics & numerical data*; D006333:Heart Failure / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D006801:Humans; D008297:Male; D011044:Poland / Q000453:epidemiology; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity