title: Clinical and electrocardiographic characteristics of patients with short QT interval in a large hospital-based population.
abstract: BACKGROUND
  Short QT syndrome is one of the underlying disorders associated with ventricular fibrillation. However, the precise prognostic implication of a short QT interval remains unclear.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the prevalence and long-term prognosis in patients with a shorter-than-normal QT interval in a large hospital-based population.
  
  
  METHODS
  We chose patients with a short Bazett QTc interval from a database consisting of 114,334 patients to determine the clinical characteristics and prognostic value of a short QT interval.
  
  
  RESULTS
  A total of 427 patients (mean age 43.4 ± 22.4 years) had a short QT interval with about a 1.2 times higher male predominance (234 men). The QTc interval was significantly longer in female than in male patients (363.8 ± 6.1 ms vs 357.1 ± 5.8 ms, P <.0001). The age-specific prevalence of patients with short QT interval was biphasic, peaking at young and old age. Atrial fibrillation and early repolarization were complicated with short QT interval in 39 (9.1%) and 26 (6.1%) patients, respectively. The prognosis of 327 patients (182 men; mean age, 46.4 ± 27.3 years) with a short QT interval could be assessed (mean follow-up period, 54.0 ± 62.0 months). During the follow-up, 2 patients, 1 of whom had early repolarization, developed life-threatening events, in contrast to 6 patients who died of noncardiac causes and did not have early repolarization.
  
  
  CONCLUSIONS
  The prevalence of a short QT interval showed a slight male preponderance and biphasic age-dependent distribution in both genders. The complication rate of atrial fibrillation was higher in those with a short QT interval than in general populations. The long-term outcome suggested that early repolarization in a short QT interval might be associated with potential risk of lethal arrhythmia.
authors.affiliation: Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Akashi
authors.initials: A
authors.lastname: Miyamoto
authors.forename: Hideki
authors.initials: H
authors.lastname: Hayashi
authors.forename: Tomohide
authors.initials: T
authors.lastname: Yoshino
authors.forename: Tamiro
authors.initials: T
authors.lastname: Kawaguchi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Taniguchi
authors.forename: Hideki
authors.initials: H
authors.lastname: Itoh
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Sugimoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Itoh
authors.forename: Takeru
authors.initials: T
authors.lastname: Makiyama
authors.forename: Joel Q
authors.initials: JQ
authors.lastname: Xue
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Murakami
authors.forename: Minoru
authors.initials: M
authors.lastname: Horie
mesh_terms: D017677:Age Distribution; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000453:epidemiology*; D001281:Atrial Fibrillation; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution