title: Incidence and prognostic value of early repolarization pattern in the 12-lead electrocardiogram.
abstract: BACKGROUND
  Early repolarization pattern is a common ECG finding characterized by J-point elevation and QRS notching or slurring in the inferior and/or lateral leads, yet little is known about its incidence and long-term prognosis in Asian populations.
  
  
  RESULTS
  We reviewed all the ECG records of the 5976 atomic-bomb survivors who were examined at least once during our biennial health examination in Nagasaki, Japan, between July 1958 and December 2004. We defined early repolarization pattern as ≥0.1-mV elevation of the J point or ST segment, with notching or slurring in at least 2 inferior and/or lateral leads. We assessed unexpected, cardiac, and all-cause death risk by Cox analysis. We identified 1429 early repolarization pattern cases (779 incident cases) during follow-up, yielding a positive rate of 23.9% and an incidence rate of 715 per 100 000 person-years. Early repolarization pattern had an elevated risk of unexpected death (hazard ratio, 1.83; 95% confidence interval, 1.12 to 2.97; P=0.02) and a decreased risk of cardiac (hazard ratio, 0.75; 95% confidence interval, 0.60 to 0.93; P<0.01) and all-cause (hazard ratio, 0.85; 95% confidence interval, 0.78 to 0.93; P<0.01) death. In addition, both slurring and notching were related to higher risk of unexpected death (hazard ratio, 2.09; 95% confidence interval, 1.06 to 4.12; P=0.03), as was early repolarization pattern manifestation in both inferior and lateral leads (hazard ratio, 2.50; 95% confidence interval, 1.29 to 4.83; P<0.01).
  
  
  CONCLUSIONS
  Early repolarization pattern is associated with an elevated risk of unexpected death and a decreased risk of cardiac and all-cause death. Specific early repolarization pattern morphologies and location are associated with an adverse prognosis.
authors.affiliation: Department of Clinical Studies, Radiation Effects Research Foundation, 1-8-6 Nakagawa, Nagasaki, Japan. harutad@rerf.or.jp
authors.forename: Daisuke
authors.initials: D
authors.lastname: Haruta
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Matsuo
authors.forename: Akira
authors.initials: A
authors.lastname: Tsuneto
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Ichimaru
authors.forename: Ayumi
authors.initials: A
authors.lastname: Hida
authors.forename: Nobuko
authors.initials: N
authors.lastname: Sera
authors.forename: Misa
authors.initials: M
authors.lastname: Imaizumi
authors.forename: Eiji
authors.initials: E
authors.lastname: Nakashima
authors.forename: Koji
authors.initials: K
authors.lastname: Maemura
authors.forename: Masazumi
authors.initials: M
authors.lastname: Akahoshi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000453:epidemiology* / Q000208:ethnology; D053840:Brugada Syndrome / Q000175:diagnosis* / Q000453:epidemiology* / Q000208:ethnology; D016757:Death, Sudden, Cardiac / Q000453:epidemiology; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D054043:Nuclear Weapons; D011379:Prognosis; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult