title: A pilot study for inducing chronic heart failure in calves by means of oral monensin.
abstract: BACKGROUND
  Heart failure remains a major cause of mortality in the United States, despite advancing technologies, newer methods of treatment, and novel devices. To evaluate such novel devices, a large-animal model of chronic heart failure is critical in carrying out preclinical animal studies.
  
  
  METHODS
  We evaluated the efficacy of oral monensin in inducing stable heart failure in five Jersey calves. Various doses of monensin were administered. Hemodynamics, pressure-volume loops, echocardiographic measurements, extent of tissue perfusion, and histopathologic data were recorded before and after induction of heart failure.
  
  
  RESULTS
  Responses were variable in the animals. One experiment showed a significant decrease in cardiac output within one week, associated with simultaneous increases in left atrial pressure, central venous pressure, and mean pulmonary artery pressure. Left ventricular pressure-volume loops showed that the slope of the end-systolic pressure-volume relation decreased markedly between the baseline and terminal study, suggesting a decrease in contractility. Echocardiographic studies indicated a decrease in ejection fraction. Histopathologic analysis in cardiac tissue showed extensive fibrosis and necrosis.
  
  
  CONCLUSIONS
  We demonstrated the feasibility of inducing and maintaining severe yet stable heart failure for up to 3 weeks in a calf model by administration of oral monensin.
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
authors.forename: Roula
authors.initials: R
authors.lastname: Zahr
authors.forename: Diyar
authors.initials: D
authors.lastname: Saeed
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Fumoto
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Horai
authors.forename: Shanaz
authors.initials: S
authors.lastname: Shalli
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Anzai
authors.forename: Yoko
authors.initials: Y
authors.lastname: Arakawa
authors.forename: Raymond
authors.initials: R
authors.lastname: Dessoffy
authors.forename: Jacquelyn
authors.initials: J
authors.lastname: Catanese
authors.forename: Alex
authors.initials: A
authors.lastname: Massiello
authors.forename: Kenneth N
authors.initials: KN
authors.lastname: Litwak
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Fukamachi
keywords: animal models; bovine; heart failure; hemodynamics; ionophores