title: Prevalence of asymptomatic ST segment elevation in right precordial leads with right bundle branch block (Brugada-type ST shift) among the general Japanese population.
abstract: OBJECTIVE
  To examine the modality and morbidity of asymptomatic ST segment elevation in leads V1 to V3 with right bundle branch block (Brugada-type ST shift).
  
  
  METHODS
  8612 Japanese subjects (5987 men and 2625 women, mean age 49.2 years) who underwent a health check up in 1997 were investigated. Those with Brugada-type ST shift underwent the following further examinations over a two year period after the initial check up: ECG, echocardiogram, 24 hour Holter monitoring, treadmill exercise testing, signal averaged ECG, and slow kinetic sodium channel blocker loading test (cibenzoline, 1.4 mg/kg).
  
  
  RESULTS
  Asymptomatic Brugada-type ST shift was found in 12 of 8612 (0.14%) subjects. Eleven of these 12 subjects were followed up. Follow up ECG exhibited persistent Brugada-type ST shift in seven of 11 (63.6%) subjects. ST shift was transformed from a saddle back to a coved type in three subjects. None of the subjects had morphological abnormalities or abnormal tachyarrhythmias. Positive late potentials were found in seven of 11 (63.6%) subjects. Augmentation of ST shift was shown by both submaximal exercise and drug administration in one of the 11 subjects (9.1%).
  
  
  CONCLUSIONS
  Asymptomatic subjects with Brugada-type ST shift were not unusual, at a rate of 0.14% in the general Japanese population. Almost all of the subjects had some abnormalities in non-invasive secondary examinations. Additional and prospective studies are needed to confirm the clinical significance and the prognosis of asymptomatic Brugada-type ST shift.
authors.affiliation: Second Department of Internal Medicine, Sapporo Medical University School of Medicine, S-1, W-16, Chuo-ku, Sapporo 060-0061, Japan. furuhasi@sapmed.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Furuhashi
authors.forename: K
authors.initials: K
authors.lastname: Uno
authors.forename: K
authors.initials: K
authors.lastname: Tsuchihashi
authors.forename: D
authors.initials: D
authors.lastname: Nagahara
authors.forename: M
authors.initials: M
authors.lastname: Hyakukoku
authors.forename: T
authors.initials: T
authors.lastname: Ohtomo
authors.forename: S
authors.initials: S
authors.lastname: Satoh
authors.forename: T
authors.initials: T
authors.lastname: Nishimiya
authors.forename: K
authors.initials: K
authors.lastname: Shimamoto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000209:etiology; D002037:Bundle-Branch Block / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D016757:Death, Sudden, Cardiac / Q000453:epidemiology; D004452:Echocardiography; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013577:Syndrome