title: Ivabradine reduced ventricular rate in patients with non-paroxysmal atrial fibrillation.
abstract: BACKGROUND
  It has been shown that Ifchannels can be found in AV node, apart from the sinus node. Previous animal studies showed that Ifinhibitor resulted in the rate-dependent reduction in AV node conduction during atrial fibrillation (AF). Therefore, we aimed to examine the effect of ivabradine on ventricular rate in patients with non-paroxysmal AF.
  
  
  METHODS
  This study was a prospective randomized, double blind, placebo-controlled study. Ivabradine, 5mg twice a day (n=21), or placebo (n=11) was administered for 1month to adult patients with non-paroxysmal AF, in addition to standard therapy. The primary end point was the change in mean ventricular rate between baseline and 1month, as assessed by 24-hour Holter.
  
  
  RESULTS
  The baseline characteristics did not differ between ivabradine and placebo groups (mean age was 59.7±13.3years, male 62.5%). Mean 24-hour ventricular rate at baseline was comparable between 2 groups. We found that ivabradine significantly decreased mean ventricular rate from 86.0±10.9beats/min to 79.2±9.6beats/min (p<0.001). In contrast, no significant change in ventricular rate was observed in placebo group (84.3±11.2 vs. 82.9±9.9beats/min, p=0.469). The effect of ivabradine on rate reduction was significantly greater than placebo (6.9±6.3 vs. 1.4±6.0beats/min, p=0.024). No drug-related adverse effects were observed in both groups.
  
  
  CONCLUSIONS
  We demonstrated that ivabradine significantly decreased ventricular rate during AF compared to placebo. Therefore, ivabradine can be a potential treatment to improve ventricular control in patients with non-paroxysmal AF. Due to the small sample size, larger studies are needed to confirm this effect of ivabradine.
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Wanwarang
authors.initials: W
authors.lastname: Wongcharoen
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Adisai
authors.initials: A
authors.lastname: Ruttanaphol
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Siriluck
authors.initials: S
authors.lastname: Gunaparn
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand. Electronic address: apromint@mail.med.cmu.ac.th.
authors.forename: Arintaya
authors.initials: A
authors.lastname: Phrommintikul
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology*; D001552:Benzazepines / Q000494:pharmacology / Q000627:therapeutic use*; D002317:Cardiovascular Agents / Q000494:pharmacology / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D000077550:Ivabradine; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D001552:Benzazepines; D002317:Cardiovascular Agents; D000077550:Ivabradine
keywords: Atrial fibrillation; Funny channel; I(f) current; Ivabradine; Rate control