School of Science and Health, University of Western Sydney, Sydney, NSW, Australia.
Acta Physiol (Oxf). 2014 Jun;211(2):297-313. doi: 10.1111/apha.12302.
The arterial baroreflex is critical to both short- and long-term regulation of blood pressure. However, human baroreflex research has been largely limited to the association between blood pressure and cardiac period (or heart rate) or indices of vascular sympathetic function. Over the past decade, emerging techniques based on carotid ultrasound imaging have allowed new means of understanding and measuring the baroreflex. In this review, we describe the assessment of the mechanical and neural components of the baroreflex through the use of carotid ultrasound imaging. The mechanical component refers to the change in carotid artery diameter in response to changes in arterial pressure, and the neural component refers to the change in R-R interval (cardiac baroreflex) or muscle sympathetic nerve activity (sympathetic baroreflex) in response to this barosensory vessel stretch. The key analytical concepts and techniques are discussed, with a focus on the assessment of baroreflex sensitivity via the modified Oxford method. We illustrate how the application of carotid ultrasound imaging has contributed to a greater understanding of baroreflex physiology in humans, covering topics such as ageing and diurnal variation, and physiological challenges including exercise, postural changes and mental stress.
动脉压力反射对于血压的短期和长期调节都至关重要。然而，人类压力反射的研究在很大程度上仅限于血压与心脏周期（或心率）或血管交感神经功能指标之间的关联。在过去的十年中，基于颈动脉超声成像的新技术为理解和测量压力反射提供了新的手段。在这篇综述中，我们描述了使用颈动脉超声成像评估压力反射的机械和神经成分。机械成分是指颈动脉直径随动脉压变化而发生的变化，而神经成分是指 R-R 间期（心脏压力反射）或肌肉交感神经活动（交感压力反射）随这种血压感觉血管拉伸而发生的变化。讨论了关键的分析概念和技术，重点介绍了通过改良牛津法评估压力反射敏感性。我们举例说明了颈动脉超声成像的应用如何有助于更好地理解人类的压力反射生理学，涵盖了年龄和昼夜变化等主题，以及运动、姿势变化和精神压力等生理挑战。
