title: Ischemic QRS prolongation as a biomarker of severe myocardial ischemia.
abstract: BACKGROUND
  Previous studies have shown that QRS prolongation is a sign of depressed collateral flow and increased rate of myocardial cell death during coronary occlusion. The aims of this study were to evaluate ischemic QRS prolongation as a biomarker of severe ischemia by establishing the relationship between prolongation and collateral flow experimentally in a dog model, and test if the same pattern of ischemic QRS prolongation occurs in man.
  
  
  METHODS
  Degree of ischemic QRS prolongation was measured using a novel method in dogs (n=23) and patients (n=52) during coronary occlusion for 5min. Collateral arterial flow was assessed in the dogs.
  
  
  RESULTS
  There was a significant correlation between QRS prolongation and collateral flow in dogs (r=0.61, p=0.008). Magnitude and temporal evolution of prolongation during ischemia were similar for dogs and humans (p=0.202 and p=0.911).
  
  
  CONCLUSIONS
  Quantification of ischemic QRS prolongation could potentially be used as a biomarker for severe myocardial ischemia.
authors.affiliation: Department of Clinical physiology and Nuclear medicine, Skåne University Hospital and Lund University, Lund, Sweden.
authors.forename: Jakob
authors.initials: J
authors.lastname: Almer
authors.affiliation: Duke University Medical Center, Durham, NC, USA.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Jennings
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Arie C
authors.initials: AC
authors.lastname: Maan
authors.affiliation: Thoracic Center, Blekingesjukhuset, Karlskrona, Sweden.
authors.forename: Michael
authors.initials: M
authors.lastname: Ringborn
authors.affiliation: Department of Health Services, University of Washington, Seattle, WA, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Maynard
authors.affiliation: Department of Clinical physiology and Nuclear medicine, Skåne University Hospital and Lund University, Lund, Sweden.
authors.forename: Olle
authors.initials: O
authors.lastname: Pahlm
authors.affiliation: Department of Clinical physiology and Nuclear medicine, Skåne University Hospital and Lund University, Lund, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Arheden
authors.affiliation: Duke University Medical Center, Durham, NC, USA.
authors.forename: Galen S
authors.initials: GS
authors.lastname: Wagner
authors.affiliation: Department of Clinical physiology and Nuclear medicine, Skåne University Hospital and Lund University, Lund, Sweden. Electronic address: henrik.engblom@med.lu.se.
authors.forename: Henrik
authors.initials: H
authors.lastname: Engblom
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D015415:Biomarkers; D001783:Blood Flow Velocity; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000503:physiopathology*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004285:Dogs; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology*; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013045:Species Specificity
chemical_list: D015415:Biomarkers
keywords: Collateral circulation; Electrocardiography; Electrophysiology; Ischemia