title: Significance of a fragmented QRS complex in patients with chronic total occlusion of coronary artery without prior myocardial infarction.
abstract: OBJECTIVE
  Fragmented QRS (fQRS) complexes that have numerous RSR´ patterns represent alteration of ventricular depolarization. We evaluated the relationship between fQRS and poor coronary collateral circulation and the diagnostic ability of fQRS for myocardial scar detection in patients with chronic total occlusion (CTO) without a history of myocardial infarction.
  
  
  METHODS
  The study population consisted of patients undergoing coronary angiography with a suspicion of CAD. Seventy-nine patients with one totally occluded major coronary artery were enrolled. Exclusion criteria were history of MI; recent acute coronary syndrome; pathologic Q wave on 12-lead ECG; cardiomyopathy or severe valvular disease; coronary artery bypass surgery or percutaneous coronary angioplasty. Collateral circulation was scored on the basis of Rentrop's classification. All patients were assessed by myocardial perfusion SPECT. Fragmented QRS was characterized as existence of an R´ or R wave or S wave notch in two adjacent leads related to the location of a major coronary artery region. Single and multiple logistic regression analyses were completed in the forward method.
  
  
  RESULTS
  Forty-nine patients had poor and 30 had well-developed collateral circulation. Fragmented QRS complexes were significantly higher in the poor collateral group (81% vs. 20%, p<0.001). Sensitivity, specificity, and the positive and negative predictive values of fQRS for myocardial scar identification were 89.4%, 87.5%, and 91.3% and 84.8%, respectively. The summed stress score and the summed rest score on SPECT were significantly higher in the poor collateral group than in the well-developed group (p<0.001) as well as in the fQRS group than the non-fQRS group (p<0.001). Logistic regression analysis revealed that the presence of fQRS was significantly and independently associated with poor collateral circulation and myocardial scar in patients with CTO.
  
  
  CONCLUSIONS
  Fragmented QRS is independently related to poor coronary collateral circulation in patients with CTO without prior myocardial infarction. Notably, it can be a good predictor of myocardial scar rather than merely ischemia, with high diagnostic accuracy.
authors.affiliation: Department of Cardiology, Heshmat Cardiovascular Research Center, Guilan University of Medical Sciences; Rasht-Iran. Kheirkhah_jalal@yahoo.com.
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Bonakdar
authors.forename: Hassan
authors.initials: H
authors.lastname: Moladoust
authors.forename: Jalal
authors.initials: J
authors.lastname: Kheirkhah
authors.forename: Esmat
authors.initials: E
authors.lastname: Abbaspour
authors.forename: Mohammad
authors.initials: M
authors.lastname: Assadian Rad
authors.forename: Arsalan
authors.initials: A
authors.lastname: Salari
authors.forename: Anoosh
authors.initials: A
authors.lastname: Barzigar
authors.forename: Bijan
authors.initials: B
authors.lastname: Shad
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000503:physiopathology; D003097:Collateral Circulation; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index