title: Early repolarization as a predictor of arrhythmic and nonarrhythmic cardiac events in middle-aged subjects.
abstract: BACKGROUND
  Early repolarization (ER) in the inferior/lateral leads predicts mortality, but whether ER is a specific sign of increased risk for arrhythmic events is not known.
  
  
  OBJECTIVE
  The purpose of this study was to study the association of ER and arrhythmic events and nonarrhythmic morbidity and mortality.
  
  
  METHODS
  We assessed the prognostic significance of ER in a community-based general population of 10,846 middle-aged subjects (mean age 44 ± 8 years). The end-points were sustained ventricular tachycardia or resuscitated ventricular fibrillation (VT-VF), arrhythmic death, nonarrhythmic cardiac death, new-onset atrial fibrillation (AF), hospitalization for congestive heart failure, or coronary artery disease during mean follow-up of 30 ± 11 years. ER was defined as ≥0.1-mV elevation of J point in either inferior or lateral leads.
  
  
  RESULTS
  After including all risk factors of cardiac mortality and morbidity in Cox regression analysis, inferior ER (prevalence 3.5%) predicted VF-VT events (n = 108 [1.0%]) with a hazard ratio (HR) of 2.2 (95% confidence interval [CI] 1.1-4.5, P = .03) but not nonarrhythmic cardiac death (n = 1235 [12.2%]), AF (n = 1659 [15.2%]), congestive heart failure (n = 1752 [16.1%]), or coronary artery disease (n = 3592 [32.9%]) (P = NS for all). Inferior ER predicted arrhythmic death in cases without other QRS complex abnormalities (multivariate HR 1.68, 95 % CI 1.10-2.58, P = .02) but not in those with ER and other coexisting abnormalities in QRS morphology (HR 1.30, 95% CI 0.86-1.96, P = .22).
  
  
  CONCLUSIONS
  ER in the inferior leads, especially in cases without other QRS complex abnormalities, predicts the occurrence of VT-VF but not nonarrhythmic cardiac events, suggesting that ER is a specific sign of increased vulnerability to ventricular tachyarrhythmias.
authors.affiliation: Medical Research Center Oulu, University of Oulu and University Hospital of Oulu, Oulu, Finland. Electronic address: juhani.junttila@oulu.fi.
authors.forename: M Juhani
authors.initials: MJ
authors.lastname: Junttila
authors.affiliation: Medical Research Center Oulu, University of Oulu and University Hospital of Oulu, Oulu, Finland.
authors.forename: Jani T
authors.initials: JT
authors.lastname: Tikkanen
authors.affiliation: Medical Research Center Oulu, University of Oulu and University Hospital of Oulu, Oulu, Finland.
authors.forename: Tuomas
authors.initials: T
authors.lastname: Kenttä
authors.affiliation: Department of Internal Medicine, Päijät-Häme Central Hospital, Lahti, Finland.
authors.forename: Olli
authors.initials: O
authors.lastname: Anttonen
authors.affiliation: Division of Cardiology Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Aapo L
authors.initials: AL
authors.lastname: Aro
authors.affiliation: Division of Cardiology Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Kimmo
authors.initials: K
authors.lastname: Porthan
authors.affiliation: Department of Internal Medicine, Päijät-Häme Central Hospital, Lahti, Finland.
authors.forename: Tuomas
authors.initials: T
authors.lastname: Kerola
authors.affiliation: National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Harri A
authors.initials: HA
authors.lastname: Rissanen
authors.affiliation: National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Paul
authors.initials: P
authors.lastname: Knekt
authors.affiliation: Medical Research Center Oulu, University of Oulu and University Hospital of Oulu, Oulu, Finland.
authors.forename: Heikki V
authors.initials: HV
authors.lastname: Huikuri
mesh_terms: D000328:Adult; D002423:Cause of Death / Q000639:trends; D016001:Confidence Intervals; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology*; D004562:Electrocardiography; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D005544:Forecasting; D006329:Heart Conduction System / Q000503:physiopathology*; D006333:Heart Failure / Q000150:complications / Q000401:mortality / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D017180:Tachycardia, Ventricular / Q000150:complications / Q000401:mortality / Q000503:physiopathology*
keywords: Early repolarization; Electrocardiogram; J waves; QRS abnormality; Sudden death