title: Enhanced transmural dispersion of repolarization in patients with J wave syndromes.
abstract: BACKGROUND
  Recently, great attention has been paid to the risk stratification of asymptomatic patients with an electrocardiographic early repolarization (ER) pattern. We investigated several repolarization parameters including the Tpeak-Tend interval and Tpeak-Tend/QT ratio in healthy individuals and patients with J wave syndrome who were aborted from sudden cardiac death.
  
  
  RESULTS
  Ninety-two subjects were enrolled: 12 patients with ventricular fibrillation associated with J waves, 40 healthy subjects with an uneventful ER pattern and 40 healthy control subjects (C) without any evident J waves. Using ambulatory electrocardiogram recordings, the average QT interval, corrected QT interval (QTc), Tpeak-Tend (Tp-e) interval, which is the interval from the peak to the end of the T wave, and Tp-e/QT ratio were calculated. Using ANOVA and post hoc analysis, there was no significant difference in the average QT and QTc in all 3 groups (QT; 396 ± 27 vs 405 ± 27 vs 403 ± 27 m, QTc; 420 ± 26 vs 421 ± 21 vs 403 ± 19 milliseconds in the C, ER pattern and J groups, respectively). The Tp-e interval and Tp-e/QT ratio were significantly more increased in the J wave group than the ER Pattern group (Tp-e: 86.7 ± 14 milliseconds vs 68 ± 13.2 milliseconds, P < 0.001, Tp-e/QT; 0.209 ± 0.04 vs 0.171 ± 0.03, P < 0.001), but they did not significantly differ between the C and ER pattern groups (Tp-e: 68.6 ± 7.5 vs 68 ± 13.2, P = 0.97, Tp-e/QT 0.174 ± 0.02 vs 0.171 ± 0.03, P = 0.4).
  
  
  CONCLUSIONS
  As novel markers of heterogeneity of ventricular repolarization, Tpeak-Tend interval and Tp-Te/QT ratio are significantly increased in patients with J wave syndromes compared to age and sex-matched uneventful ER.
authors.affiliation: Department of Cardiology Department of Health Science, Asahikawa Medical University, Asahikawa, Japan. ahmed@asahikawa-med.ac.jp
authors.forename: Ahmed
authors.initials: A
authors.lastname: Karim Talib
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Sato
authors.forename: Naka
authors.initials: N
authors.lastname: Sakamoto
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Tanabe
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Saijo
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Kawamura
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Hasebe
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D053840:Brugada Syndrome / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D016022:Case-Control Studies; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control; D015716:Electrocardiography, Ambulatory; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy