Zanchetti A, Mancia G
Istituto di Clinica Medica Generale e Terapia Medica, Università di Milano, Italy.
Hypertension. 1991 Nov;18(5 Suppl):III13-21. doi: 10.1161/01.hyp.18.5_suppl.iii13.
Both arterial baroreceptor reflexes and cardiopulmonary reflexes are modified in human hypertension. The arterial baroreceptor reflex regulation of heart rate, when tested by both vasoactive drug injection and the neck chamber technique, has been shown to be reset and blunted. Arterial baroreceptor reflex control of blood pressure, studied by the neck chamber technique, has been found to be reset to more effectively buffer increases in blood pressure than blood pressure falls, but without any loss of overall reflex sensitivity. Cardiopulmonary reflexes, tested by passive leg raising and by application of lower body negative pressure, are also blunted, and their dysfunction involves not only control of peripheral vasoconstriction but also that of renin release. These readjustments of arterial and cardiopulmonary reflexes make buffering of blood pressure falls or of blood volume changes less effective in hypertension. These readjustments appear to be a consequence, rather than a cause, of hypertension. In particular, the blunting of cardiopulmonary reflexes is induced more by left ventricular hypertrophy than by hypertension. It is very marked in hypertensive patients with echocardiographic evidence of left ventricular hypertrophy and very significantly improves when left ventricular hypertrophy is made to regress by prolonged antihypertensive therapy; significant blunting of cardiopulmonary reflexes has also been found in young athletes with marked left ventricular hypertrophy but normal blood pressure. Whether structural changes in the carotid and aortic wall and possibly in the heart are equally important in the readjustment of arterial baroreceptor reflexes is incompletely clarified at the moment, although there are indications that functional and structural modifications may both be involved.
在人类高血压中，动脉压力感受器反射和心肺反射均发生了改变。通过血管活性药物注射和颈室技术测试时，动脉压力感受器对心率的反射调节已被证明发生了重置和钝化。通过颈室技术研究发现，动脉压力感受器对血压的反射控制已被重置，以便更有效地缓冲血压升高而非血压下降，但整体反射敏感性并未丧失。通过被动抬腿和施加下体负压测试的心肺反射也会钝化，其功能障碍不仅涉及外周血管收缩的控制，还涉及肾素释放的控制。动脉和心肺反射的这些重新调整使得在高血压中缓冲血压下降或血容量变化的效果降低。这些重新调整似乎是高血压的结果而非原因。特别是，心肺反射的钝化更多是由左心室肥厚引起的，而非高血压。在有超声心动图证据显示左心室肥厚的高血压患者中非常明显，并且当通过长期抗高血压治疗使左心室肥厚消退时，心肺反射会非常显著地改善；在有明显左心室肥厚但血压正常的年轻运动员中也发现了明显的心肺反射钝化。目前尚不完全清楚颈动脉和主动脉壁以及可能心脏的结构变化在动脉压力感受器反射的重新调整中是否同样重要，尽管有迹象表明功能和结构改变可能都参与其中。
