title: Bepridil inhibits sub-acute phase of atrial electrical remodeling in canine rapid atrial stimulation model.
abstract: Background The effect of bepridil, a multichannel blocker, on atrial electrical remodeling was evaluated in a canine rapid atrial stimulation model. Methods and Results In 10 beagle dogs, the right atrial appendage (RAA) was paced at 400 beats/min for 2 weeks. The atrial electrophysiological parameters, including effective refractory period (AERP), were evaluated at three atrial sites: RAA, the right atrium close to the inferior vena cava (IVC) and the left atrium (LA), during the time course of rapid pacing. Five of the dogs were given bepridil (10 mg . kg (-1) . day(-1) po). In the control group, AERP was significantly shortened at all atrial sites and the AERP shortening (DeltaAERP) was larger for the RAA and LA than at the IVC site (p<0.05). In the bepridil group, DeltaAERP was smaller than that of the controls at all atrial sites, and the AERP started to return slowly to the pre-pacing level in the second week, regardless of the continuation of rapid pacing. Conclusions In a canine rapid atrial stimulation model, bepridil suppressed AERP shortening. Bepridil might have a reverse electrical remodeling effect, at least for AERP shortening, because it showed slow recovery of AERP in the subacute phase of rapid atrial pacing. (Circ J 2006; 70: 206 - 213).
authors.affiliation: Departments of Angiocardiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara 228-8555, Japan. dsatou@med.kitasato-u.ac.jp
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sato
authors.forename: Shinichi
authors.initials: S
authors.lastname: Niwano
authors.forename: Ryuta
authors.initials: R
authors.lastname: Imaki
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Masaki
authors.forename: Sae
authors.initials: S
authors.lastname: Sasaki
authors.forename: Masaru
authors.initials: M
authors.lastname: Yuge
authors.forename: Shoji
authors.initials: S
authors.lastname: Hirasawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sasaki
authors.forename: Masahiko
authors.initials: M
authors.lastname: Moriguchi
authors.forename: Hiroe
authors.initials: H
authors.lastname: Niwano
authors.forename: Hirokuni
authors.initials: H
authors.lastname: Yoshimura
authors.forename: Tohru
authors.initials: T
authors.lastname: Izumi
mesh_terms: D000818:Animals; D015764:Bepridil / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004285:Dogs; D006325:Heart Atria / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology*; D008955:Models, Cardiovascular; D009200:Myocardial Contraction / Q000187:drug effects*
chemical_list: D002121:Calcium Channel Blockers; D015764:Bepridil