title: QRS duration and left ventricular ejection fraction (LVEF) in non-ST segment elevation myocardial infarction (NSTEMI).
abstract: BACKGROUND
  Non-traditional EKG parameters such as QRS pattern and QRS duration (QRSd) are being investigated in acute coronary syndrome as prognostic markers. Following an infarction, the heart attempts to compensate for myocardial loss through remodeling which eventually lowers the ejection fraction (LVEF). Our objective is to evaluate the relationship between the QRSd at the time of NSTEMI and extent of coronary artery disease (CAD) and changes in LVEF.
  
  
  RESULTS
  Patients admitted with NSTEMI between 08/01/2006 and 9/30/2012 were included. Patients were classified into high or low QRSd at cutoff value of 90ms noted on initial EKG after excluding bundle-branch block. A total of 536 patients with mean age of 66±14years were included. 49% were male and majority were African American (73%). Patients within the higher QRSd group had a lower LVEF at the time of the NSTEMI compared to those with QRSd <90ms (47±15% vs. 50±13%; p<0.038). The LVEF remained lower in the high QRS group on follow up to 12months (47±15% vs. 52±11%; p<0.001). The high QRSd group had a higher incidence of severe LV dysfunction at baseline (27% vs. 18%; p<0.045). Logistic regression analysis revealed that a QRSd ≥90ms was also independently associated with a severely reduced LVEF on follow-up (OR=2.7; CI 1.55-4.69; p<0.001).
  
  
  CONCLUSIONS
  QRSd ≥90ms at the time of NSTEMI is predictive of three-vessel/left main coronary artery involvement and a lower LVEF. This depression in LVEF is maintained for up to 12months. Thus, the QRSd at time of NSTEMI has additional prognostic significance.
authors.affiliation: Department of Cardiology, Lehigh Valley Hospital, United States. Electronic address: dr.mahekshah@yahoo.co.in.
authors.forename: Mahek
authors.initials: M
authors.lastname: Shah
authors.affiliation: Department of Medicine, Einstein Medical Center, United States.
authors.forename: Obiora
authors.initials: O
authors.lastname: Maludum
authors.affiliation: Department of Cardiology, Einstein Medical Center, United States.
authors.forename: Vikas
authors.initials: V
authors.lastname: Bhalla
authors.affiliation: Department of Medicine, Einstein Medical Center, United States.
authors.forename: Toni Anne
authors.initials: TA
authors.lastname: De Venecia
authors.affiliation: Department of Medicine, Einstein Medical Center, United States.
authors.forename: Shantanu
authors.initials: S
authors.lastname: Patil
authors.affiliation: Department of Medicine, Einstein Medical Center, United States.
authors.forename: Karla
authors.initials: K
authors.lastname: Curet
authors.affiliation: Department of Cardiology, Einstein Medical Center, United States.
authors.forename: Nwakile
authors.initials: N
authors.lastname: Chinualumogu
authors.affiliation: Department of Cardiology, Einstein Medical Center, United States.
authors.forename: Gregg S
authors.initials: GS
authors.lastname: Pressman
authors.affiliation: Department of Cardiology, Einstein Medical Center, United States; Department of Medicine, Sydney-Kimmel Medical College, United States.
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Figueredo
mesh_terms: D000368:Aged; D003331:Coronary Vessels / Q000473:pathology / Q000503:physiopathology; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000072658:Non-ST Elevated Myocardial Infarction / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology*; D013997:Time Factors; D014481:United States; D020257:Ventricular Remodeling / Q000502:physiology*
keywords: Ejection fraction; Left main; Non-ST elevation myocardial infarction; QRS duration; Severe left ventricular dysfunction; Triple vessel disease