Heart rate reduction with ivabradine prevents the global phenotype of left ventricular remodeling.
The aim of this study was to investigate the effect of chronic heart rate (HR) reduction with the hyperpolarization-activated current inhibitor ivabradine on the global phenotype of left ventricular (LV) remodeling in a ligated rat model. Seven days after coronary artery ligation, Wistar rats received ivabradine (10 mg · kg(-1) · day(-1) administered in drinking water) [myocardial infarction + ivabradine (MI+IVA), n = 22] or vehicle only (drinking water) (MI, n = 20) for 90 days. A sham group (n = 20) was included for model validation. MI+IVA rats had 12% lower HR (P < 0.01), improved LV volumes, 15% higher LV ejection fraction (LVEF, P < 0.01) than MI rats, and 33% reductions in both plasma atrial natriuretic peptide (ANP, P = 0.052) and cardiac hydroxyproline. Using patch-clamp, action potential duration was reduced and transient outward current density increased (P < 0.05). Cardiac energy metabolism was also improved (+33% creatine phosphate, P < 0.001; +15% ATP; and +9% energy charge, P < 0.05). Significant correlations were found between HR and parameters of cardiac metabolism, ANP, and LVEF (all P < 0.05). The HR-reducing properties of ivabradine prevent changes in the global phenotype of LV remodeling in the rat, optimize energy consumption, and avoid electrophysiological and structural remodeling.
Department of Cardiology, University of Ferrara, Ferrara, Italy. claudio.ceconi@unife.it
Claudio
C
Ceconi
Laura
L
Comini
Silvia
S
Suffredini
Francesca
F
Stillitano
Muriel
M
Bouly
Elisabetta
E
Cerbai
Alessandro
A
Mugelli
Roberto
R
Ferrari
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology*; D004562:Electrocardiography; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D006321:Heart / Q000187:drug effects* / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D000077550:Ivabradine; D008297:Male; D009203:Myocardial Infarction / Q000378:metabolism / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D016277:Ventricular Function, Left / Q000187:drug effects* / Q000502:physiology; D020257:Ventricular Remodeling / Q000187:drug effects* / Q000502:physiology
D001552:Benzazepines; D000077550:Ivabradine