title: Effect of pimobendan on the incidence of arrhythmias in small breed dogs with myxomatous mitral valve degeneration.
abstract: OBJECTIVE
  To determine if pimobendan, a phosphodiesterase III inhibitor and calcium sensitizer with positive survival benefits, has an effect on incidence of arrhythmias compared to placebo in small breed dogs with congestive heart failure (CHF) due to myxomatous mitral valve degeneration (MMVD).
  
  
  METHODS
  Eight client-owned small breed dogs (<15 kg) with CHF due to MMVD.
  
  
  METHODS
  A prospective double-blind randomized placebo-controlled crossover study design was used. Data were recorded at baseline and 2 weeks post-administration of placebo or pimobendan. Average heart rate and incidence of arrhythmia were determined from 24 h Holter analysis. Owners completed a quality of life (QOL) questionnaire at each time point and recorded sleeping respiratory rates (SRR). Mixed effects analysis of variance, with dog as the random variable was used to compare values obtained between baseline, placebo, and pimobendan.
  
  
  RESULTS
  Compared to baseline, QOL scores were significantly improved following administration of either placebo or pimobendan (p = 0.021 and p < 0.001, respectively). No significant differences in type or incidence of supraventricular or ventricular arrhythmia were identified. Average heart rate with pimobendan was significantly lower than baseline (p < 0.001). Compared to baseline, SRR was significantly lower with pimobendan (p = 0.004), and significantly different from placebo (p = 0.045).
  
  
  CONCLUSIONS
  No significant difference between pimobendan and placebo was found on incidence of supraventricular or ventricular arrhythmia. The decrease in average heart rate and SRR may be reflective of superior heart failure control achieved with pimobendan therapy.
authors.affiliation: Department of Veterinary Medicine and Epidemiology, University of California, One Shields Avenue, Davis, CA 95616, USA.
authors.forename: Geri A
authors.initials: GA
authors.lastname: Lake-Bakaar
authors.affiliation: Department of Veterinary Medicine and Epidemiology, University of California, One Shields Avenue, Davis, CA 95616, USA.
authors.forename: Manreet K
authors.initials: MK
authors.lastname: Singh
authors.affiliation: Department of Population Health and Reproduction, University of California, One Shields Avenue, Davis, CA 95616, USA.
authors.forename: Philip H
authors.initials: PH
authors.lastname: Kass
authors.affiliation: Department of Veterinary Medicine and Epidemiology, University of California, One Shields Avenue, Davis, CA 95616, USA. Electronic address: lggriffiths@ucdavis.edu.
authors.forename: Leigh G
authors.initials: LG
authors.lastname: Griffiths
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000188:drug therapy / Q000209:etiology / Q000662:veterinary*; D001947:Breeding; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D004311:Double-Blind Method; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000188:drug therapy / Q000662:veterinary*; D006801:Humans; D015994:Incidence; D008297:Male; D008945:Mitral Valve Prolapse / Q000150:complications / Q000188:drug therapy / Q000662:veterinary*; D010067:Ownership; D011446:Prospective Studies; D011724:Pyridazines / Q000008:administration & dosage / Q000627:therapeutic use*; D011788:Quality of Life; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D002316:Cardiotonic Agents; D011724:Pyridazines; C041648:pimobendan
keywords: Canine; Congestive heart failure; Ventricular premature complex; Vetmedin