title: Endothelin system and atrial fibrillation post-cardiac surgery.
abstract: OBJECTIVE
  We investigated the relation between the endothelin system and atrial fibrillation.
  
  
  BACKGROUND
  Endothelin has been implicated in the pathophysiology of atrial fibrillation, but the exact role of A- and B-receptors is unknown.
  
  
  METHODS
  We obtained right atrial biopsies from patients in sinus rhythm and preserved left ventricular function, undergoing off-pump coronary artery bypass grafting. The expression of endothelin, A- and B-receptors was measured using real time reverse-transcribed polymerase chain reaction.
  
  
  RESULTS
  We studied 52 patients (45 male, mean age 66+/-1 years, mean ejection fraction 52+/-1%). During a 5-day post-operative period, persistent atrial fibrillation occurred in 15 patients (28.8%). Endothelin mRNA expression was comparable in patients who subsequently developed atrial fibrillation and in those maintaining sinus rhythm. However, the former group displayed down-regulation of endothelin A- (by approximately 60%, p=0.0059) and of B-receptors (by approximately 40%, p=0.0084). The decreased endothelin A-receptor expression could predict atrial fibrillation occurrence (Wilks lambda=0.86, F=6.16, p=0.017).
  
  
  CONCLUSIONS
  Decreased endothelin A- and B-receptor expression is associated with atrial fibrillation after bypass surgery.
authors.affiliation: Department of Cardiology, University of Ioannina, Ioannina, Greece.
authors.forename: Theofilos M
authors.initials: TM
authors.lastname: Kolettis
authors.forename: Zenon S
authors.initials: ZS
authors.lastname: Kyriakides
authors.forename: Eleni
authors.initials: E
authors.lastname: Zygalaki
authors.forename: Stamatis
authors.initials: S
authors.lastname: Kyrzopoulos
authors.forename: Loukas
authors.initials: L
authors.lastname: Kaklamanis
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Nikolaou
authors.forename: Evi S
authors.initials: ES
authors.lastname: Lianidou
authors.forename: Dimitrios Th
authors.initials: DT
authors.lastname: Kremastinos
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology*; D001706:Biopsy; D016009:Chi-Square Distribution; D047549:Coronary Artery Bypass, Off-Pump; D016232:Endothelins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012333:RNA, Messenger / Q000378:metabolism; D012372:ROC Curve; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
chemical_list: D016232:Endothelins; D012333:RNA, Messenger