title: Twenty-four hour Holter monitoring in finishing cattle housed outdoors.
abstract: BACKGROUND
  Atrial premature complexes have been reported to be the most common arrhythmia in cattle and is suspected to be secondary to systemic disease, especially gastrointestinal disease. In order to properly identify pathologic arrhythmia in cattle, the normal rhythm and arrhythmia prevalence should be defined. The objective of this study was to determine the normal heart rate, rhythm, number of ventricular premature complexes (VPCs), and atrial premature complexes (APCs) in unrestrained Angus steers.
  
  
  METHODS
  Twenty-seven client owned steers with unremarkable physical examinations and serum biochemical analyses were used.
  
  
  METHODS
  Twenty-four hour Holter monitors, attached by a custom-made harness, were retrospectively evaluated. Three lead electrocardiographic registrations of good quality and normal sinus rhythm were obtained from all steers in the study.
  
  
  RESULTS
  The mean heart rate was 66.8 bpm ± 16.4 bpm. Ventricular premature complexes were rare (noted in 14.8% of steers), and APCs were common (noted in 85% of the steers). Simple second degree AV block was observed in 18.5% of the steers.
  
  
  CONCLUSIONS
  In summary, healthy steers have rare single VPCs, although it is possible for an individual animal to have apparent more frequent VPCs. Mean heart rate varies with a diurnal pattern similar to other species. Atrial premature complexes are the most prevalent abnormality observed in feedlot steers.
authors.affiliation: Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, 1800 Denison Ave., Manhattan, KS 66506, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Frese
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, 1800 Denison Ave., Manhattan, KS 66506, USA. Electronic address: jthomason11@vet.k-state.edu.
authors.forename: J D
authors.initials: JD
authors.lastname: Thomason
authors.affiliation: Department of Animal Science and Industry, Kansas State University, 232 Weber Hall, Manhattan, KS 66506, USA.
authors.forename: C
authors.initials: C
authors.lastname: Reinhardt
authors.affiliation: Beef Cattle Institute, College of Veterinary Medicine, Kansas State University, 1 Trotter Hall 1800 Denison Ave., Manhattan, KS 66506, USA.
authors.forename: S
authors.initials: S
authors.lastname: Bartle
authors.affiliation: Beef Cattle Institute, College of Veterinary Medicine, Kansas State University, 1 Trotter Hall 1800 Denison Ave., Manhattan, KS 66506, USA.
authors.forename: D
authors.initials: D
authors.lastname: Rethorst
authors.affiliation: Department of Animal and Food Sciences, Texas Tech University, Box 42141, Lubbock, TX 79409, USA.
authors.forename: G H
authors.initials: GH
authors.lastname: Loneragan
authors.affiliation: Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, 1800 Denison Ave., Manhattan, KS 66506, USA.
authors.forename: D
authors.initials: D
authors.lastname: Thomson
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D018880:Atrial Premature Complexes / Q000503:physiopathology / Q000662:veterinary*; D002417:Cattle / Q000502:physiology*; D002418:Cattle Diseases / Q000175:diagnosis / Q000503:physiopathology*; D015716:Electrocardiography, Ambulatory / Q000662:veterinary*; D006339:Heart Rate; D008297:Male; D012016:Reference Values; D012189:Retrospective Studies; D018879:Ventricular Premature Complexes / Q000503:physiopathology / Q000662:veterinary*
keywords: Cattle; Electrocardiography; Holter monitors