title: Prolonged QRS duration on the resting ECG is associated with sudden death risk in coronary disease, independent of prolonged ventricular repolarization.
abstract: BACKGROUND
  Abnormalities of ventricular repolarization as well as depolarization have been associated with increased risk of ventricular arrhythmias.
  
  
  OBJECTIVE
  To evaluate the relative contribution of these predictors to risk of sudden cardiac death (SCD) in patients with coronary artery disease (CAD).
  
  
  METHODS
  In the ongoing Oregon Sudden Unexpected Death Study, adult residents from the Portland, Oregon, metropolitan area (population ~1 million) who suffered SCD were identified prospectively (2002-2007). Of these, we analyzed the subgroup of SCDs that had a resting 12-lead ECG prior to SCD and also had associated CAD. Comparisons were conducted with a control group of subjects with known CAD but no history of SCD from the same geographic region. Corrected QT interval (QTc), JT interval (JTc), QRS duration (QRSd), and other parameters were measured from ECG prior and unrelated to SCD. Analysis of left ventricular function was limited to those subjects who had undergone echocardiography prior to and remote from SCD.
  
  
  RESULTS
  A total of 642 SCD cases (71 ± 13 years, 62% male) were compared to 450 controls (66 ± 12 years, 64% male). SCD cases had significantly longer QRSd (102 ± 25 ms vs 97 ± 20 ms, P = .0008) as well as JTc (348 ± 44 ms vs 339 ± 34 ms, P = .0006) vs controls. In cases with prolonged QRSd, 38% had severe left ventricular systolic dysfunction and 62% had normal, mild, or moderately decreased left ventricular systolic function. In a multivariable model, QRSd, JTc, age, and severe left ventricular systolic dysfunction were independent predictors. There was minimal overlap between prolonged QRSd and JTc in both case and control groups (3% and 4%, respectively).
  
  
  CONCLUSIONS
  Prolonged QRSd, JTc, and severe left ventricular systolic dysfunction had independent contributions to risk of SCD in coronary disease, in this community-based setting.
authors.affiliation: Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
authors.forename: Carmen
authors.initials: C
authors.lastname: Teodorescu
authors.forename: Kyndaron
authors.initials: K
authors.lastname: Reinier
authors.forename: Audrey
authors.initials: A
authors.lastname: Uy-Evanado
authors.forename: Jo
authors.initials: J
authors.lastname: Navarro
authors.forename: Ronald
authors.initials: R
authors.lastname: Mariani
authors.forename: Karen
authors.initials: K
authors.lastname: Gunson
authors.forename: Jonathan
authors.initials: J
authors.lastname: Jui
authors.forename: Sumeet S
authors.initials: SS
authors.lastname: Chugh
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003327:Coronary Disease / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology*; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology*; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D009922:Oregon / Q000453:epidemiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D018487:Ventricular Dysfunction, Left / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology*