title: [Relationship between new-onset atrial fibrillation and sympathetic neural remodeling in a canine acute myocardial infarction model].
abstract: OBJECTIVE
  To establish the canine model of new-onset atrial fibrillation (AF) after acute myocardial infarction (AMI), and explore the relationship between new-onset AF and sympathetic neural remodeling in this model.
  
  
  METHODS
  Twenty four adult mongrel dogs were randomly divided into 4 groups by applying random number table. Group A (n=6): ligate the left circumflex artery (LCX). Group B (n=6): ligate the LCX and right atrial anterior artery and right atrial middle artery. Group C (n=6): ligate left anterior descending artery.Group D (n=6): sham operation.Sequential electrophysiology study was performed in all dogs to determine the AF induction rate, AF duration, effective refractory period (ERP), the density of tyrosine hydroxylase (TH) and norepinephrine transporter (NET) before AMI or sham operation, and at 30 min, 2 hours and 4 hours after AMI or sham operation.
  
  
  RESULTS
  (1) The highest AF induction rate of right atrium and left auricle was 96.7%(58/60) and 95.0%(57/60) in group B, 81.7%(49/60) and 38.3%(23/60) in group A, 28.3%(17/60) and 35.0%(21/60) in group C, 20.0%(12/60) and 33.3%(20/60) in group D. (2) At 4 hours after AMI, AF duration was significantly prolonged in group B(193.50±54.67) s, compared with group A(53.83±9.37) s, group C(45.00±19.50) s, and group D(16.67±4.50) s (all P<0.05). (3) In group B, the ERP of AF was prolonged at 30 minutes after AMI and shortened at 2 hours and 4 hours after AMI compared with baseline level(all P<0.05). (4) The TH density of left atrium ((3 485±694) µm2/mm2) and left auricle((2 645±454) µm2/mm2) in group A and the TH density of left atrium ((7 873±1159) µm2/mm2) and left auricle((3 070±605) µm2/mm2) in group B were significantly higher than those in group C ((1 474±475) µm2/mm2, (1 177±277) µm2/mm2) and group D ((678±206) µm2/mm2, (489±125) µm2/mm2) (all P<0.05), and the TH density of right atrium and right auricle in group B were higher than group A (all P<0.05). The NET density of left atrium((476±75) µm2/mm2) and left auricle ((414±52) µm2/mm2) in group A and the NET density of left atrium((527±81) µm2/mm2) and left auricle((429±85) µm2/mm2) in group B were lower than that in group C ((1 044±105) µm2/mm2, (867±67) µm2/mm2) and group D ((1 438±60) µm2/mm2, (1 027±119) µm2/mm2) (all P<0.05).
  
  
  CONCLUSIONS
  Ligating the LCX, right atrial anterior artery and right atrial middle artery at the same time can significantly increase the success rate in establishing the canine model of new-onset atrial fibrillation after acute myocardial infarction and can also increase the AF duration.Cardiac sympathetic remodeling after acute myocardial infarction is associated with induction and duration of AF.
authors.affiliation: Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, China.
authors.forename: Tuerhong
authors.initials: T
authors.lastname: Zukela
authors.forename: Qina
authors.initials: Q
authors.lastname: Zhou
authors.forename: Hongli
authors.initials: H
authors.lastname: Wang
authors.forename: Xianhui
authors.initials: X
authors.lastname: Zhou
authors.forename: Yaodong
authors.initials: Y
authors.lastname: Li
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jinxin
authors.initials: J
authors.lastname: Li
authors.forename: Jianghua
authors.initials: J
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xing
authors.affiliation: Email: tangbaopeng1111@163.com.
authors.forename: Baopeng
authors.initials: B
authors.lastname: Tang
mesh_terms: D000818:Animals; D056988:Anterior Wall Myocardial Infarction; D001281:Atrial Fibrillation; D004195:Disease Models, Animal; D004285:Dogs; D006325:Heart Atria; D013564:Sympathetic Nervous System