title: The relationship between repolarization parameters and serum electrolyte levels in patients with J wave syndromes.
abstract: BACKGROUND
  Intravenous administration of magnesium (Mg(2+)) is effective for polymorphic ventricular tachycardia via homogenization of transmural ventricular repolarization. Mg(2+) likely plays some role in the heterogeneity of repolarization in J wave syndromes.
  
  
  OBJECTIVE
  To investigate the relationship between the repolarization parameters and serum Mg(2+), potassium (K(+)), and calcium (Ca(2+)) levels in J wave syndromes.
  
  
  METHODS
  Thirteen J-wave syndrome patients (Brugada and early repolarization [ER] syndromes), with documented episodes of ventricular fibrillation (VF), and 13 ER pattern (ERP) or Brugada type ECG patients were enrolled (25 males, mean age 48 ± 15 years). The 12-lead ECG-derived parameters including the QT, QT dispersion (QTd), Tpeak-Tend (Tp-e) interval, Tp-e dispersion (Tp-ed), Tp-e/QT ratio, and activation recovery interval (ARI) dispersion were calculated; the correlations between these parameters and electrolytes including Mg(2+), K(+), and Ca(2+) were analyzed.
  
  
  RESULTS
  Although there was no association between serum K(+) or Ca(2+) and QTd, there was a strong negative correlation between serum Mg(2+) and QTd in J wave syndrome patients with a history of VF (r = -0.715, p = 0.006). Also, there was a tendency for a negative correlation between Mg(2+) and Tp-ed or ARI dispersion in J wave syndrome patients with a history of VF (r = -0.513, p = 0.072 and r = -0.53, p = 0.063, respectively). On the other hand, in 13 patients with a Brugada type ECG or ERP, no correlation was observed between serum Mg(2+) and the QTd, Tp-ed or ARI dispersion.
  
  
  CONCLUSIONS
  Serum Mg(2+) may play an important role in the cardiac repolarization process in J wave syndromes.
authors.affiliation: Department of Cardiology, Asahikawa Medical University.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Sato
authors.affiliation: Department of Medical Laboratory and Blood Center, Asahikawa Medical University Hospital.
authors.forename: Rie
authors.initials: R
authors.lastname: Sasaki
authors.affiliation: Department of Medical Laboratory and Blood Center, Asahikawa Medical University Hospital.
authors.forename: Marina
authors.initials: M
authors.lastname: Imahashi
authors.affiliation: Department of Medical Laboratory and Blood Center, Asahikawa Medical University Hospital.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Ito
authors.affiliation: Department of Medical Laboratory and Blood Center, Asahikawa Medical University Hospital.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Saito
authors.affiliation: Department of Medical Laboratory and Blood Center, Asahikawa Medical University Hospital.
authors.forename: Haruyo
authors.initials: H
authors.lastname: Kubota
authors.affiliation: Department of Cardiology, Asahikawa Medical University.
authors.forename: Ahmed Karim
authors.initials: AK
authors.lastname: Talib
authors.affiliation: Department of Cardiology, Asahikawa Medical University.
authors.forename: Naka
authors.initials: N
authors.lastname: Sakamoto
authors.affiliation: Department of Medical Laboratory and Blood Center, Asahikawa Medical University Hospital.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Akasaka
authors.affiliation: Division of Community Medicine and Epidemiology, Department of Health Science, Asahikawa Medical University.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Saijo
authors.affiliation: Department of Cardiology, Asahikawa Medical University.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Kawamura
authors.affiliation: Department of Medical Laboratory and Blood Center, Asahikawa Medical University Hospital.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujii
authors.affiliation: Department of Cardiology, Asahikawa Medical University.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Hasebe
mesh_terms: D000328:Adult; D001145:Arrhythmias, Cardiac / Q000097:blood* / Q000503:physiopathology*; D053840:Brugada Syndrome / Q000097:blood / Q000503:physiopathology; D002118:Calcium / Q000097:blood; D004562:Electrocardiography; D004573:Electrolytes / Q000097:blood*; D005260:Female; D006801:Humans; D008274:Magnesium / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D013577:Syndrome; D017180:Tachycardia, Ventricular / Q000097:blood* / Q000503:physiopathology*; D014693:Ventricular Fibrillation / Q000097:blood / Q000503:physiopathology
chemical_list: D004573:Electrolytes; D008274:Magnesium; D011188:Potassium; D002118:Calcium
keywords: J wave syndrome; magnesium; repolarization