直立位递增运动负荷时左室收缩期血流动力学变化  

Dynamics of left ventricular systole during progressive exercise in sitting position

作　　者：孙飙[1] 马继政[1] 

机构地区：[1]南京体育学院运动人体科学系,南京210014

出　　处：《中国康复医学杂志》2003年第12期747-750,共4页Chinese Journal of Rehabilitation Medicine

摘　　要：本研究采用多普勒超声心动图观察运动负荷递增时左室收缩期血流动力学的变化。方法:12名普通大学生,平均年龄20±0.74岁。受试者在MonarkErgometer817型功率自行车上进行踏车运动,踏车速度为60圈/分,功率从50W开始,两分钟后增至100W,此后每两分钟增加25W,直至力竭,做超声心动图。结果:随着运动强度增加,心指数由安静时2.85±0.33l/min/m2增至最大负荷时为10.86±1.10l/min/m2;主动脉瓣瓣口血流速度的最大值和平均值分别由安静状态的0.74±0.38m/s和0.41±0.08m/s增至最大负荷时的1.48±0.1m/s和1.17±0.75m/s;收缩期主动脉瓣跨瓣压差分别比安静时增加4倍和6倍。当HR超过115.00±9.17次/分时的运动强度(约40%VO2max),每搏量呈平台趋势。结论:随着运动强度的增加,左室射血时间减少,在递增运动负荷初期,收缩期主动脉瓣跨瓣压差增大可以提高左室射血速度和每搏量,但超过40%VO2max运动强度时,主动脉瓣跨瓣压差增大主要作用是提高左室射血速度,致使每搏量维持在一个相对恒定的范围内。Objective:To assess systolic dynamics of left ventricular during progressive upright cycle exercise in young man.Method:12undergraduate were collected in the research.Their average age was20±0.74years.They rode Monark817bicycles at the60RPM from50W and increased25W every2minutes until they could not maintain the speed.Doppler echocardiolography was used to examine the heart' s changes during the exercise.Result:Cardiac index increased form2.85±0.33l/(min·m 2 )at rest to10.86±1.10l/(min·m 2 )at peak time.The peak transmitral flow velocities increased from0.74±0.38m/s at rest to1.60±0.10m/s at peak exercise and the mean transmitral flow velocities increased from0.41±0.08m/s at rest to1.17±0.75m/s at peak exercise.The peak and mean transmitral pressure gradient rose fourfold and six fold from rest to peak exercise.The stroke volume increased significantly from rest to at the heart rate of115.00±9.17beat/min(about40%of VO 2max )and remained constant.Conclusion:At low levels of exertion,increases in transmitral pressure gradient with exercise may serve to augment aortic flow velocities and stroke volume with the progressively shortening diastolic time period.But the intensity surpassed the40%of VO 2max ,increases in transmitral pressure gradient may serve principally to augment aortic flow velocities,which keeps the stroke volume constant.

关 键 词：运动负荷 左室收缩期 血流动力学 多普勒超声心动图 左室射血速度 

分 类 号：R87[医药卫生—运动医学]