Baroreceptor reflex in heart failure

Abstract

Congestive heart failure is a syndrome that is usually initiated by a reduction in pump function of the heart, i.e. a decrease incardiac output. Initially, a reduction in cardiac output leads to unloading of baroreceptor reflex that, in turn, increases heart rate throughvago-sympathetic mechanisms and total peripheral resistance via an increase in sympathetic outflow to vascular beds. In this review weare thinking on how baroreceptor reflex plays a role in the abnormal control of the circulation in heart failure. This review and our recentstudies suggest that: (1) baroreceptor reflex is blunted in heart failure; (2) central angiotensin Ⅱ and reactive oxygen species play animportant role in blunted baroreceptor reflex; (3) cardiac sympathetic afferent stimulation and chemoreceptor reflex inhibit baroreceptorreflex; and (4) exercise training normalizes abnormal reflexes in the heart failure state. 心力衰竭是以心脏泵血功能降低(心输出量减少)为始动因素的临床综合征。心输出量降低首先引起动脉压力感受性反射失负荷,进而通过迷走-交感机制加快心率;同时,支配血管床的交感传出活动增强,进而增加总外周阻力。本文主要论述在心力衰竭状态下压力感受性反射在循环功能异常调控中的作用机制。本综述及我们近年的研究表明:(1)在心力衰竭状态下压力感受性反射功能明显减弱;(2)中枢血管紧张素Ⅱ和活性氧在压力感受性反射功能失调中发挥关键作用;(3)心交感传入刺激和化学感受性反射能抑制压力感受性反射;(4)适当的运动可以部分纠正异常的心血管反射活动。