title: Fragmented QRS complexes not typical of a bundle branch block: a marker of greater myocardial perfusion tomography abnormalities in coronary artery disease.
abstract: BACKGROUND
  Fragmented QRS (FQRS) complexes, not typical of a bundle branch block, are a marker of regional myocardial injury. The extent of stress myocardial perfusion imaging (MPI) abnormalities with FQRS patterns is not known.
  
  
  RESULTS
  Twelve-lead electrocardiograms (ECGs) in 501 patients undergoing stress MPI were studied. FQRS was defined as a QRS duration of 120 milliseconds or less, with notches or slurs of QRS complexes, on 2 contiguous leads of a coronary artery territory. Abnormal MPI was defined as a regional summed stress score (SSS) and summed rest score (SRS) of 3 or greater based on a 17-segment model. Patients with a typical bundle (n = 26), paced rhythm (n = 2), and Q waves (n = 64) were excluded. Of the remaining 409 patients (mean age, 58 +/- 13 years; 52% male), 155 (38%) had FQRS on the ECG. FQRS patients had a higher mean SSS, SRS, and global summed difference score and a lower left ventricular ejection fraction (all P < .001), as well as greater regional stress MPI scar (69% vs 11%, P < .001). FQRS pattern sensitivity was 75% and specificity was 94% for a corresponding regional MPI scar. On logistic regression, SSS, SRS, summed difference score, left ventricular ejection fraction, and regional scar were univariate predictors of the FQRS pattern on the ECG (all P < .01), and any regional scar (odds ratio, 32; P < .001) was a multivariate predictor.
  
  
  CONCLUSIONS
  FQRS complexes on an ECG are a marker of higher stress MPI perfusion and functional abnormalities. Regional FQRS patterns denote the presence of a greater corresponding focal regional myocardial scar on stress MPI.
authors.affiliation: Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA. jmahenth@iupui.edu
authors.forename: Jo
authors.initials: J
authors.lastname: Mahenthiran
authors.forename: Bilal R
authors.initials: BR
authors.lastname: Khan
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Sawada
authors.forename: Mithilesh K
authors.initials: MK
authors.lastname: Das
mesh_terms: D001145:Arrhythmias, Cardiac / Q000150:complications / Q000175:diagnosis*; D002037:Bundle-Branch Block / Q000175:diagnosis*; D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000175:diagnosis*