急性无氧功率自行车运动对颈总动脉弹性模量和局部血液动力学的影响

目的研究急性无氧功率自行车运动对不同性别人体颈总动脉弹性模量和局部血液动力学的影响。方法以9名男性和8名女性20～30岁年龄段的健康志愿者作为研究对象,使用无氧功率自行车持续进行4组相同强度的急性运动训练。应用彩色超声多普勒分别检测静息状态及每组运动训练后的颈总动脉管径波形、轴心流速波形,用电子自动血压计同步检测心率和血压大小。运用经典血液动力学理论对检测数据进行分析,计算颈总动脉的弹性模量和局部血液动力学参数,包括压力-应变弹性模量、流量率、周向应变、壁面切应力和振荡剪切指数。结果运动后心率增加;随着运动的积累,颈总动脉弹性模量呈增加趋势;一个心动周期内轴心血流速度和流量率最大值与平均值上升,流速和流量率最小值下降;收缩压和平均压增高,舒张压无明显改变;周向应变无明显改变;切应力最大值有明显增加的趋势,切应力最小值下降趋势明显;振荡剪切指数也有增大的趋势。结论急性无氧功率自行车运动可增加20～30岁年龄段不同性别志愿者的颈总动脉弹性模量,并对颈总动脉局部血液运动学和动力学功能参数产生明显的影响。本文结果将为无氧运动调控脑血管功能提供有用的血液动力学信息。

Acute effects of anaerobic exercises by a bicycle ergometer on elastic modulus and local hemodynamics in common carotid arteries

Objective To investigate acute effects of anaerobic exercises by a bicycle ergometer on arterial elastic modulus and local hemodynamics in human common carotid arteries with different genders. Methods Nine male and eight female healthy young volunteers at the age of 20-30 year-old successively underwent four groups of exercise trainings with the same workload by an anaerobic bicycle ergometer. The waveforms of arterial diameter and center-line blood velocity were measured in the right common carotid artery using a color Ultrasonic Doppler for each group when at rest and right after exercise training. The heart rate, systolic and diastolic blood pressures were simultaneously measured in brachial artery using an automatic electronic sphygmomanometer. All the measured data were analyzed based upon the principle of classic hemodynamics. The arterial elastic modulus and local hemodynamic parameters, including pressure-strain elastic modulus, flow rate, circumferential strain, wall shear stress and oscillatory shear index (OSI), were then calculated. Results The heart rate and arterial elastic modulus increased after exercises; with the accumulative exercises, in one cardiac cycle, the maximum and mean center-line velocity and flow rate increased while the minimum velocity and flow rate decreased; the systolic and mean blood pressure increased while diastolic blood pressure exhibited no significant change; no significant change could be found in the circumferential strain; the maximum and mean shear stress increased significantly while the minimum shear stress reduced; the oscillatory shear index also increased. Conclusions The anaerobic exercises by a bicycle ergometer may increase the arterial elastic modulus and induce significant effects on local hemodynamic parameters in common carotid arteries for young volunteers with different genders at the age of 20 30 year old. The results in this study could provide useful hemodynamic information for regulation of cerebrovascular function by anaerobic exercises.