Modulation of Sympathetic Activity and Innervation With Chronic Ivabradine and β-Blocker Therapies: Analysis of Hypertensive Rats With Heart Failure:

Background:Whether the reduction of heart rate with ivabradine (IVA) could affect sympathetic activation and cardiac innervation in heart failure (HF) remains unknown.Purpose:The present study assessed the chronic effects of IVA and β-blocker on the systemic and local sympathetic nervous systems of hypertensive animals with HF.Methods and Results:The Dahl salt-sensitive rats received chronic IVA, bisoprolol (BIS), or placebo (CTL) therapy. The survival of the animal models with IVA and BIS significantly improved (median; 19.7 in IVA and 19.7 in BIS vs 17.0 weeks in CTL, P < .001). A similar decrease in 24-hour heart rate (mean; 305 in IVA and 329 in BIS vs 388 beats/min in CTL, P < .001) without effect on blood pressure, and an improvement in the left ventricular dysfunction (mean fractional shortening; 56.7% in IVA and 47.8% in BIS vs 39.0% in CTL, P < .001) were observed in the animals with IVA and BIS. However, a negative inotropic effect was only observed in the animals with BIS. Excessive urinary nor...