Importance of morphological changes in T-U waves during bepridil therapy as a predictor of ventricular arrhythmic event.
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.
Kurokawa
Sayaka
S
Department of Cardio-Angiology, Kitasato University School of Medicine, Sagamihara, Japan. ksayaka@med.kitasato-u.ac.jp
Niwano
Shinichi
S
Kiryu
Michiro
M
Murakami
Masami
M
Ishikawa
Shoko
S
Yumoto
Yoshihiro
Y
Moriguchi
Masahiko
M
Niwano
Hiroe
H
Kosukegawa
Tomoko
T
Izumi
Tohru
T
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*
D000889:Anti-Arrhythmia Agents; D015764:Bepridil