title: The role of the fragmented QRS complexes on a routine 12-lead ECG in predicting non-responsiveness to cardiac resynchronization therapy.
abstract: OBJECTIVE
  Cardiac resynchronization therapy (CRT) is introduced as a promising therapeutic option in heart failure (HF) patients with ventricular dyssynchrony.The challenge, however, is identifying the patients who are suitable candidates for this procedure. Fragmented QRS (fQRS) is associated with subendocardial fibrosis and myocardial scars. In this study, we aimed to evaluate the role of fragmented QRS complex on a routine 12-lead ECG as a predictor of response to CRT.
  
  
  METHODS
  Sixty-five consecutive patients with HF who underwent CRT, were studied. Patients' resting 12-lead ECGs were analyzed to find presence of fQRS by a cardiologist. Echocardiographic response to CRT was defined as ≥15% decrease in left ventricular end-systolic volume (LVESV) after CRT implantation. Response to CRT was compared between patients with and without fQRS.
  
  
  RESULTS
  The study group included 27 women (41.5%) and 38 men (58.5%) with a mean (±SD) age of 62±12 years. 27 patients (41.5%) had fQRS in their basal ECGs. Totally 46 patients (70.8%) responded to CRT in a way that the mean left ventricular ejection fraction (%) significantly increased, and left ventricular end diastolic volume (LVEDV) significantly decreased after CRT (p<0.001 and p=0.001 respectively). In multivariate logistic analysis, lack of fQRS was found to be a predictor of response to CRT (OR: 4.553, 95% CI: 1.345-15.418, p=0.015).
  
  
  CONCLUSIONS
  We showed that the fQRS complex, as a sign of myocardial scar, predicts non-responsiveness to CRT. Therefore, fQRS may help selecting of CRT candidates.
authors.affiliation: Cardiovascular Research Center, Faculty of Medicine, Guilan University of Medical Sciences; Rasht-Iran. hmoladost@yahoo.com.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Assadian Rad
authors.forename: Narges
authors.initials: N
authors.lastname: Tabarzan Baboli
authors.forename: Anoosh
authors.initials: A
authors.lastname: Barzigar
authors.forename: Jalal
authors.initials: J
authors.lastname: Keirkhah
authors.forename: Soheil
authors.initials: S
authors.lastname: Soltanipour
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Bonakdar
authors.forename: Fardin
authors.initials: F
authors.lastname: Mirbolouk
authors.forename: Hassan
authors.initials: H
authors.lastname: Moladoust
mesh_terms: D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D058406:Cardiac Resynchronization Therapy; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests