title: Seasonal, weekly, and circadian distribution of ventricular fibrillation in patients with J-wave syndrome from the J-PREVENT registry.
abstract: BACKGROUND
  Ventricular fibrillation (VF) in Brugada syndrome (BrS) is known to occur more frequently during nighttime and from spring to early summer. In this study, we investigated whether early repolarization syndrome (ERS) has the same seasonal, weekly, and circadian distribution of VF events as BrS using data from the "J-wave associated with prior cardiac event" (J-PREVENT) registry.
  
  
  METHODS
  The study included 90 consecutive patients with BrS and 31 patients with ERS during a mean follow-up of 49±37 months. Follow-up data from implantable cardioverter-defibrillators were evaluated in all cases.
  
  
  RESULTS
  In patients with ERS, the circadian distribution of VF episodes differed among the four 6-h periods, with a significant peak from midnight to 6:00 am (p<0.01) similar to that observed in BrS patients. However, VF occurred more frequently on weekends in patients with ERS, whereas on weekdays in patients with BrS (p<0.01). The months of peak VF occurrence also differed between the groups, with the frequency of VF episodes at peak between December and March in ERS patients and between March and June in BrS patients. In ERS patients, VF events had an inverse correlation with air temperature (r=-0.726, p<0.01).
  
  
  CONCLUSIONS
  ERS and BrS patients show similar nighttime increases in the occurrence of VF, but different seasonal and weekly distributions, suggesting a pathophysiological difference between the two syndromes.
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Maeda
authors.affiliation: Department of Cardiology, National Disaster Medical Center, Tokyo, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Department of Heart Rhythm Management, Yokohama Rosai Hospital, Yokohama, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nogami
authors.affiliation: Department of Cardiology, Musashino Red Cross Hospital, Tokyo, Japan.
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Yamauchi
authors.affiliation: Department of Cardiology, Yokosuka Kyosai Hospital, Yokosuka, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Osaka
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shirai
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Ihara
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yokoyama
authors.affiliation: Department of Cardiovascular Medicine, Kameda General Hospital, Kamogawa, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Heart Center, Yokohama City Bay Red Cross Hospital, Yokohama, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Okishige
authors.affiliation: Department of Cardiology, Yokohama Minami Kyosai Hospital, Yokohama, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Nishizaki
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirao
keywords: Brugada syndrome; Early-repolarization; Electrocardiography; Sudden death; Ventricular fibrillation