title: Importance of morphological changes in T-U waves during bepridil therapy as a predictor of ventricular arrhythmic event.
abstract: BACKGROUND
  Although bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during bepridil therapy and was examined as a predictor of ventricular arrhythmic events.
  
  
  RESULTS
  The study population consisted of 113 patients on bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V(2-5). During bepridil treatment, the QTc interval was prolonged from 0.45+/-0.01 to 0.49+/-0.01 s(1/2) in all patients (P<0.0001) and any type of T-U wave change (fused U, slurred, bifid, biphasic or negative) appeared in 73% of event-free and 100% of event groups. In univariate analysis, QTc interval before bepridil (P=0.028), a wide QRS complex (P=0.042) before bepridil, biphasic (P=0.027) or negative (P=0.002) T-U waves in the stable phase, and the new appearance of biphasic (P=0.004) or negative (P<0.0001) T-U waves exhibited significant differences. In multivariate analysis, only newly appeared negative T-U wave exhibited a significant difference (odds ratio 10.13, 95% confidence interval = 0.031-2.302, P=0.041).
  
  
  CONCLUSIONS
  In patients with stable bepridil treatment, a change in T-U wave morphology might be a useful predictor of ventricular arrhythmia assisting the QT interval.
authors.affiliation: Department of Cardio-Angiology, Kitasato University School of Medicine, Sagamihara, Japan. ksayaka@med.kitasato-u.ac.jp
authors.forename: Sayaka
authors.initials: S
authors.lastname: Kurokawa
authors.forename: Shinichi
authors.initials: S
authors.lastname: Niwano
authors.forename: Michiro
authors.initials: M
authors.lastname: Kiryu
authors.forename: Masami
authors.initials: M
authors.lastname: Murakami
authors.forename: Shoko
authors.initials: S
authors.lastname: Ishikawa
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yumoto
authors.forename: Masahiko
authors.initials: M
authors.lastname: Moriguchi
authors.forename: Hiroe
authors.initials: H
authors.lastname: Niwano
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kosukegawa
authors.forename: Tohru
authors.initials: T
authors.lastname: Izumi
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000503:physiopathology; D015764:Bepridil / Q000008:administration & dosage* / Q000009:adverse effects; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016171:Torsades de Pointes / Q000188:drug therapy* / Q000503:physiopathology*
chemical_list: D000889:Anti-Arrhythmia Agents; D015764:Bepridil