Effects of ivabradine on heart rate and left ventricular function in healthy cats and cats with hypertrophic cardiomyopathy

Am J Vet Res. 2012 Feb;73(2):202-12. doi: 10.2460/ajvr.73.2.202.


Objective: To evaluate the effects of the pacemaker funny current (I(f)) inhibitor ivabradine on heart rate (HR), left ventricular (LV) systolic and diastolic function, and left atrial performance in healthy cats and cats with hypertrophic cardiomyopathy (HCM).

Animals: 6 healthy cats and 6 cats with subclinical HCM.

Procedures: Anesthetized cats underwent cardiac catheterization and were studied over a range of hemodynamic states induced by treatment with esmolol (200 to 400 μg/kg/min, IV), esmolol and dobutamine (5 μg/kg/min, IV), ivabradine (0.3 mg/kg, IV), and ivabradine and dobutamine. Left ventricular systolic and diastolic function, cardiac output, and left atrial function were studied via catheter-based methods and echocardiography.

Results: Treatment with ivabradine resulted in a significant reduction of HR, rate-pressure product, and LV contractile function and a significant increase in LV end-diastolic pressure, LV end-diastolic wall stress, and LV relaxation time constant (tau) in cats with HCM. Concurrent administration of ivabradine and dobutamine resulted in a significant increase of LV contractility and lusitropy, with blunted chronotropic effects of the catecholamine. Left atrial performance was not significantly altered by ivabradine in cats with HCM. Regression analysis revealed an association between maximum rate of LV pressure rise and tau in cats with HCM.

Conclusions and clinical relevance: Ivabradine had significant effects on several cardiovascular variables in anesthetized cats with HCM. Studies in awake cats with HCM are needed to clinically validate these findings.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic beta-1 Receptor Agonists / pharmacology
  • Adrenergic beta-1 Receptor Agonists / therapeutic use
  • Adrenergic beta-1 Receptor Antagonists / pharmacology
  • Adrenergic beta-1 Receptor Antagonists / therapeutic use
  • Animals
  • Benzazepines / pharmacology*
  • Benzazepines / therapeutic use
  • Blood Pressure / drug effects
  • Cardiomyopathy, Hypertrophic / drug therapy
  • Cardiomyopathy, Hypertrophic / veterinary*
  • Cardiovascular Agents / pharmacology
  • Cardiovascular Agents / therapeutic use*
  • Cat Diseases / drug therapy*
  • Cats
  • Dobutamine / pharmacology
  • Dobutamine / therapeutic use
  • Dose-Response Relationship, Drug
  • Heart Rate / drug effects*
  • Ivabradine
  • Propanolamines / pharmacology
  • Propanolamines / therapeutic use
  • Ventricular Function, Left / drug effects*


  • Adrenergic beta-1 Receptor Agonists
  • Adrenergic beta-1 Receptor Antagonists
  • Benzazepines
  • Cardiovascular Agents
  • Propanolamines
  • Ivabradine
  • Dobutamine
  • esmolol