Control of Sinus Node Tachycardia as an Additional Therapy in Patients With Decompensated Heart Failure

Sympathetic hyperactivity and consequent increase in heart rate (HR) are physiological responses to low cardiac output in patients with decompensated heart failure (DHF). However, elevated HR may become inappropriate in these patients, increasing myocardial oxygen demand and decreasing diastolic filling time and might lead to hemodynamic deterioration, ventricular dysfunction (tachycardiomyopathy) and clinical deterioration. Studies show the elevated HR is a predictor of poor prognosis in DHF. Subanalyses of large clinical trials using beta blockers (BBs) demonstrate the adequate control of HR correlates with a better outcome in patients with stable chronic heart failure (HF). However, use of BBs in patients with DHF is limited due to negative inotropic and hypotensive effects of these drugs. As alternative to BBs, ivabradine has shown to increase survival of patients with chronic stable systolic HF. Compared to BBs, ivabradine has the advantage of "pure" negative chronotropic effect, no effect on myocardial contractility or peripheral vascular resistance. Despite the inhibition of I (f) has been validated as a therapeutic option in patients with stable HF, there are no studies available on this strategy in patients with DHF. We hypothesized that HR control by ivabradine might improve clinical, hemodynamic and neurohormonal parameters in patients with DHF. The aim of this study was to evaluate the efficacy of HR control with ivabradine in patients with DHF.