[Heart rate and experimental myocardial ischaemia].
Every increase in heart rate represents a poor prognostic factor in cardiology, and multiple arguments have now led to the belief that reducing heart rate is a major therapeutic challenge. A comparison of the pharmacological effects of If current inhibitors such as zatebradine, and more recently ivabradine (Procoralan) and beta-blockers, have demonstrated experimentally that reductions in heart rate and myocardial contractile force contribute equally to the reduction in myocardial oxygen consumption in the normal heart. Conversely, at a similar level of reduction in heart rate, the lack of a concomitant negative inotropic effect with ivabradine affords longer diastolic perfusion times than beta-blockers. In other words, a negative inotropic effect is deleterious when an increase in coronary blood flow is required. Hence, if the anti-ischaemic effects afforded by an If current inhibitor and a beta-blocker are roughly comparable, the former are clearly of higher benefit than beta-blockers in the treatment of myocardial dysfunction accompanying cardiac ischaemia-reperfusion, especially myocardial stunning.
Berdeaux
Alain
A
Laboratoire de Pharmacologie, Inserm, Faculté de Médecine, Créteil, France. berdeaux@im3.inserm.fr
Colin
Patrice
P
Monnet
Xavier
X
Ghaleh
Bijan
B
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D001919:Bradycardia / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D017202:Myocardial Ischemia / Q000188:drug therapy / Q000503:physiopathology*
D000319:Adrenergic beta-Antagonists