title: Fragmented wide QRS on a 12-lead ECG: a sign of myocardial scar and poor prognosis.
abstract: BACKGROUND
  Fragmented QRS (duration <120 ms) on a 12-lead ECG represents myocardial scar in patients with coronary artery disease. However, the significance of fragmented QRS has not been defined in the presence of a wide QRS (wQRS; duration >or=120 ms). We postulate that fragmented wQRS (f-wQRS) due to bundle branch block, premature ventricular complexes, or paced rhythms (f-pQRS) signify myocardial scar and higher mortality.
  
  
  RESULTS
  Patients who underwent cardiac evaluation with nuclear stress imaging or cardiac catheterization and had wQRS (bundle branch block, premature ventricular complex, or pQRS) were studied. f-wQRS was defined by the presence of >2 notches on the R wave or the S wave and had to be present in >or=2 contiguous inferior (II, III, aVF), lateral (I, aVL, V(6)) or anterior (V(1) to V(5)) leads. ECG analyses of 879 patients (age, 66.7+/-11.4 years; male, 97%; mean follow-up, 29+/-18 months) with bundle branch block (n=310), premature ventricular complex (n=301), and pQRS (n=268) revealed f-wQRS in 415 (47.2%) patients. Myocardial scar was present in 440 (50%) patients. The sensitivity, specificity, positive predictive value, and negative predictive value of f-wQRS for myocardial scar were 86.8%, 92.5%, 92.0%, and 87.5%, respectively. The sensitivity and specificity for diagnosing myocardial scar were 88.6% and 94.4%, 81.4% and 88.4%, and 89.8% and 95.7% for f-bundle branch block, f-premature ventricular complex, and f-pQRS, respectively. f-wQRS was associated with mortality after adjusting for age, ejection fraction, and diabetes (P=0.017).
  
  
  CONCLUSIONS
  f-wQRS on a standard 12-lead ECG is a moderately sensitive and highly specific sign for myocardial scar in patients with known or suspected coronary artery disease. f-wQRS is also an independent predictor of mortality.
authors.affiliation: Krannert Institute of Cardiology, Roudebush VA Medical Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA. midas@iupui.edu
authors.forename: Mithilesh K
authors.initials: MK
authors.lastname: Das
authors.forename: Hussam
authors.initials: H
authors.lastname: Suradi
authors.forename: Waddah
authors.initials: W
authors.lastname: Maskoun
authors.forename: Mark A
authors.initials: MA
authors.lastname: Michael
authors.forename: Changyu
authors.initials: C
authors.lastname: Shen
authors.forename: Jonathan
authors.initials: J
authors.lastname: Peng
authors.forename: Gopi
authors.initials: G
authors.lastname: Dandamudi
authors.forename: Jo
authors.initials: J
authors.lastname: Mahenthiran
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D002921:Cicatrix / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009206:Myocardium; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D018879:Ventricular Premature Complexes / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology