title: Beta-blocker prophylaxis for atrial fibrillation after coronary artery bypass grafting in patients with sympathovagal imbalance.
abstract: BACKGROUND
  Atrial fibrillation (AF) is the most common arrhythmia after coronary bypass grafting (CABG) resulting in a prolonged hospital stay and higher costs. The withdrawal of beta-blocker and a sympathovagal imbalance were identified as risk factors for AF.
  
  
  METHODS
  In our study we performed a measuring of standard deviation of all normal RR intervals (SDNN) among 142 consecutive patients with beta-blocker therapy before CABG in order to identify a collective who had an increased risk due to a withdrawal of beta-blocker medication. A sympathovagal imbalance was predefined as a SDNN below 30 ms. Patients were divided into four groups according to the results of SDNN and the continuous beta-blocker therapy: group I: SDNN < or = 30 ms or less and withdrawal of beta-blocker therapy (26 patients); group II: SDNN < or = 30 ms and continuously beta-blocker therapy (33 patients); group III: SDNN > 30 ms and withdrawal of beta-blocker therapy (40 patients); group IV: SDNN > 30 ms and continuous beta-blocker therapy (43 patients).
  
  
  RESULTS
  Atrial fibrillation occurred in 39 patients (27%) after surgery. Patients of group I showed a higher incidence of AF (14 of 26 patients, 54%) than patients of group II (7 of 33 patients, 21%; p < 0.009), patients of group III (8 of 40 patients, 20%; p < 0.004), or patients of group IV (10 of 43 patients, 23%; p < 0.01). We found a significantly higher incidence of diabetes mellitus (47 vs 14% of patients; p < 0.0001) in patients with a sympathovagal imbalance than patients with a SDNN above 30 ms.
  
  
  CONCLUSIONS
  The results of our study suggest a sympathovagal imbalance and withdrawal of a beta-blocker therapy increase the risk of postoperative AF. A continuous beta-blocker therapy reduces the risk especially in patients with a sympathovagal imbalance and should always be practiced.
authors.affiliation: Department of Cardiology, West-German Heart Centre, University of Duisburg-Essen, Essen, Germany. marco.budeus@medizin.uni-essen.de
authors.forename: Marco
authors.initials: M
authors.lastname: Budeus
authors.forename: Peter
authors.initials: P
authors.lastname: Feindt
authors.forename: Emmeran
authors.initials: E
authors.lastname: Gams
authors.forename: Heinrich
authors.initials: H
authors.lastname: Wieneke
authors.forename: Stefan
authors.initials: S
authors.lastname: Sack
authors.forename: Raimund
authors.initials: R
authors.lastname: Erbel
authors.forename: Christian
authors.initials: C
authors.lastname: Perings
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D001281:Atrial Fibrillation / Q000517:prevention & control*; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D003920:Diabetes Mellitus / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D014630:Vagus Nerve / Q000503:physiopathology*
chemical_list: D000319:Adrenergic beta-Antagonists