title: Omega-3 fatty acids do not alter P-wave parameters in electrocardiogram or expression of atrial connexins in patients undergoing coronary artery bypass surgery.
abstract: OBJECTIVE
  We previously reported omega-3 polyunsaturated fatty acids (n-3PUFAs) supplementation does not reduce atrial fibrillation (AF) following coronary artery bypass graft (CABG) surgery. The aim of the present study is to evaluate the impact of n-3 PUFAs on electrocardiogram (ECG) atrial arrhythmic markers and compare with expression of gap-junction proteins, Connexins.
  
  
  RESULTS
  Subset of clinical trial subjects with right atrial sampling during CABG surgery included. Twelve-lead ECG performed at recruitment and at surgery [after supplementation with n-3 PUFA (∼1.8 g/day) or matched placebo] for ∼14 days. Electrocardiograms analysed for maximum P-wave duration (P-max) and difference between P-max and minimum P-wave duration, P-wave dispersion (PWD). Right atrial specimens analysed for expression of Connexins 40 and 43 using real-time quantitative polymerase chain reaction (qPCR) and western blot. Serum levels of n-3 PUFA at baseline, at surgery, and atrial tissue levels at surgery collated from file. Postoperative AF was quantified by analysing data from stored continuous electrograms. A total of 61 patients (n-3 PUFA 34, Placebo 27) had ECG analysis and AF burden, of which 52 patients (26 in each group) had qPCR and 16 (8 in each group) had western blot analyses for Connexins 40 and 43. No difference between the two groups in ECG parameters or expression of Connexin 40 or 43. P-wave dispersion in the preoperative ECG independently predicted occurrence of AF following CABG surgery.
  
  
  CONCLUSIONS
  Omega-3 polyunsaturated fatty acids supplementation does not alter pro-arrhythmic P-wave parameters in ECG or connexin expression in human atrium with no effect on the incidence of AF following CABG surgery.
authors: Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK p.saravanan@nhs.net.
authors: Palaniappan
authors: P
authors: Saravanan
authors: Faculty of Medicine, University of Southampton, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK.
authors: Annette L
authors: AL
authors: West
authors: Department of Cardiology, University Hospital of South Manchester, Manchester, UK.
authors: Ben
authors: B
authors: Bridgewater
authors: Department of Cardiology, University Hospital of South Manchester, Manchester, UK.
authors: Neil C
authors: NC
authors: Davidson
authors: Faculty of Medicine, University of Southampton, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK.
authors: Philip C
authors: PC
authors: Calder
authors: Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK.
authors: Halina
authors: H
authors: Dobrzynsky
authors: Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK.
authors: Andrew
authors: A
authors: Trafford
authors: Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK.
authors: Stephen C
authors: SC
authors: O'Neill
mesh_terms: D000368:Aged; D020517:Atrial Appendage / Q000378:metabolism; D001281:Atrial Fibrillation / Q000453:epidemiology*; D018031:Connexin 43 / Q000378:metabolism*; D017630:Connexins / Q000378:metabolism*; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D004311:Double-Blind Method; D004562:Electrocardiography; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000453:epidemiology; D011300:Preoperative Care; D012333:RNA, Messenger / Q000032:analysis; D012044:Regression Analysis; D006113:United Kingdom; D000097003:Gap Junction alpha-5 Protein
chemical_list: D018031:Connexin 43; D017630:Connexins; D015525:Fatty Acids, Omega-3; D012333:RNA, Messenger; D000097003:Gap Junction alpha-5 Protein
keywords: Atrial fibrillation; Connexin 40; Connexin 43; Coronary artery bypass graft; Electrocardiogram; Omega-3 polyunsaturated fatty acid; P-wave