Heart rate per se impacts cardiac function in patients with systolic heart failure and pacing: a pilot study

Abstract

AimsThis study was designed to compare the specific effects of two heart rates (HR), 55 and 75 b.p.m., in patients with heart failure (HF). Methods and resultsPatients with chronic HF, left ventricular ejection fraction (LVEF) 35%, and a pacemaker with .90% of paced QRS, were included in a randomized cross-over trial of two 3-month periods where pacing rate was set at either 55 or 75 b.p.m. At the end of each period, patients were examined and radionuclide ventriculography, echocardiography, and blood sampling were performed for centralized and blinded analysis. Two patients did not complete the study because of early worsening while paced at 75 b.p.m. Twelve patients completed the study. Compared with 75 b.p.m., pacing at 55 b.p.m. was associated with a higher LVEF [þ4.7% (2.6-6.7), P , 0.001], lower B-type natriuretic peptide levels [291 pg/mL (2148 to 233), P , 0.01], lower systolic pulmonary artery pressure (41 + 10 vs. 47 + 10 mmHg, P ¼ 0.02) and lower NYHA (New York Heart Association) class (2.2 + 0.6 vs. 2.6 + 0.5, P ¼ 0.03). The baseline pacing rate prior to inclusion had no effect on results. ConclusionHR per se may impact cardiac function and low HR might be beneficial in patients with systolic HF compared with intermediate HR.--

Changes in collagen metabolism account for ventricular functional recovery following beta-blocker therapy in patients with chronic heart failure

“…LVEF and DcT increased greatest in patients with the larger reduction in HR following bisoprolol therapy even in this study. Such results are comparable to previous studies [18,[26][27][28]. It was reported that HR reduction has most significant contribution to improved LVEF with carvedilol therapy [29].…”

Ivabradine, a novel heart rate slower: is it a sword of double blades in patients with idiopathic dilated cardiomyopathy?

“…This is supported by the study of Logeart et al (9) who found a signifi cantly lower NYHA class (2.2+0.6 vs. 2.6+0.5, p=0.03) in patients with HF paced at 75 bpm as compared with pacing at 55 bpm.…”

Limited role for ivabradine in the treatment of chronic heart failure

“…A similar pattern is seen in heart failure treatment trials 14 17. In the absence of any therapeutic agents that were able to lower heart rate alone, it was difficult to design studies to define the independent effects of heart rate control dissociated from other effects of β-blockade 18 19…”