Mulder Paul, Thuillez Christian
INSERM U644, Faculté de Médecine et de Pharmacie, Rouen, France.
Adv Cardiol. 2006;43:97-105. doi: 10.1159/000095431.
Heart failure is a major health problem, and is one of the few cardiovascular diseases that increased its prevalence over the last decade. Increased heart rate, generally observed in patients with heart failure, is involved in the deterioration of cardiac pump function. However, the effects of 'pure' heart rate reduction on the progression of heart failure are unknown. In a rat model of heart failure, ivabradine, a blocker of I(f) channels reduces dose-dependently heart rate without modification of blood pressure. This heart rate reduction is associated with an improvement in cardiac function. After chronic administration, this improvement of cardiac function persists after ivabradine withdrawal, revealing an improvement in intrinsic myocardial function. This beneficial effect could be explained by direct effects of heart rate reduction induced by ivabradine, i.e. improved myocardial oxygen supply to demand ratio, and/or myocardial tissular effects induced by chronic decrease in heart rate such, i.e. decreased extracellular collagen accumulation, increased myocardial microcirculation. In conclusion, 'pure' chronic heart rate reduction can be beneficial in heart failure.
心力衰竭是一个主要的健康问题，并且是过去十年中患病率有所增加的少数心血管疾病之一。心力衰竭患者通常会出现心率加快，这与心脏泵功能的恶化有关。然而，“单纯”降低心率对心力衰竭进展的影响尚不清楚。在心力衰竭大鼠模型中，If通道阻滞剂伊伐布雷定可剂量依赖性降低心率而不改变血压。这种心率降低与心脏功能改善相关。长期给药后，停用伊伐布雷定后心脏功能的改善仍持续存在，表明心肌内在功能得到改善。这种有益作用可以通过伊伐布雷定诱导的心率降低的直接作用来解释，即改善心肌氧供需比，和/或长期心率降低诱导的心肌组织效应，如细胞外胶原积累减少、心肌微循环增加。总之，“单纯”慢性心率降低对心力衰竭可能有益。
