title: Atrial natriuretic peptide (ANP) suppresses acute atrial electrical remodeling in the canine rapid atrial stimulation model.
abstract: OBJECTIVE
  Atrial electrical remodeling is considered to play an important role in the appearance of atrial fibrillation. The effect of atrial natriuretic peptide (ANP) on atrial electrical remodeling was evaluated in a canine atrial stimulation model.
  
  
  METHODS
  In 15 beagle dogs, electrodes for pacing and recording were fixed on the atrial surface. In 10/15 dogs, rapid atrial stimulation (400 bpm) was performed for 7 h at the right atrial appendage (RAA) and the remaining 5 were used as the sham without rapid pacing. In 5/10 dogs with rapid pacing, human atrial natriuretic peptide (ANP) was infused (1.0 microg/kg/min). The effective refractory period (ERP) and the monophasic action potential duration (MAP) were evaluated at 0, 3, and 7 h after rapid pacing. The expression levels of mRNAs of ion channels or transporters were evaluated from the atrial samples of sham and after a 7 hour pacing.
  
  
  RESULTS
  In the control group with rapid pacing (n=5), the atrial ERP and MAP duration were shortened at all atrial sites, e.g., ERP from 148+/-14 ms to 109+/-8 ms at RAA, P=0.006. In contrast in the ANP group, neither the ERP nor MAP duration showed a significant shortening and the effect of ANP on hemodynamic parameter was relatively small. Expression levels of the mRNA were not significantly different between the control and ANP groups.
  
  
  CONCLUSIONS
  Administration of ANP prevented the shortening of the ERP and MAP duration in the rapid atrial stimulation model. The effect of ANP on atrial electrical remodeling was considered to be due to its direct action on the myocardium.
authors: Department of Emergency and Critical Care Medicine, Kitasato University School of Medicine, 1-15-1, Kitasato, Sagamihara, Kanagawa, 228-8555, Japan. yoshidat@med.kitasato-u.ac.jp
authors: Toru
authors: T
authors: Yoshida
authors: Shinichi
authors: S
authors: Niwano
authors: Hiroe
authors: H
authors: Niwano
authors: Ryuta
authors: R
authors: Imaki
authors: Daisuke
authors: D
authors: Satoh
authors: Yoshio
authors: Y
authors: Masaki
authors: Kazumi
authors: K
authors: Nakazato
authors: Kazui
authors: K
authors: Soma
authors: Tohru
authors: T
authors: Izumi
mesh_terms: D000818:Animals; D016275:Atrial Function / Q000187:drug effects* / Q000502:physiology*; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D004285:Dogs; D004594:Electrophysiology
chemical_list: C472955:NPPA protein, human; D009320:Atrial Natriuretic Factor