运动负荷对高原地区青少年心缩间期的影响

EFFECT OF EXERCIS TOLERANCE ON STI IN ADOLESCENTS AT HIGH ALTITUDE

采用逐级负荷踏车实验和阻抗心动图的方法,测定居住3417m高原13～16岁藏汉族青少年静息状态下,运动后即刻及恢复期心率和左心收缩间期,结果显示,静息状态下两组STI各数值无差异,藏族运动后即刻的PEP短于汉族,LVET长于汉族,P/L有明显差异(P<0.01),经心率矫正后藏族运动后即刻LVETI及QS_2I均长于汉族,恢复期短于汉族,形成交叉曲线,说明居住高原的汉藏族人群的心功能差别在青少年时已经出现。提示:藏族在运动状态下有良好的心力储备及对运动负荷的适应能力,其原因可能与生长发育的环境及种群遗传有关。

The systolic time interval(STI) and HR were measured by gradual loading bicycle ergometer and impedance cardiogram to Tibetan and Han's adolescents (13～16 years old) who resided at 3 417m while they were at rest,immediately and after loading. The result of study was showed as follows, the values of STI between Tibetan and Han appeared indifferances. The PEP in Tibetan was less, but LVET larger in Han and P/L in both of them which showed obvious differances(P<0.01). The LVEFI and QS_2 I in Tibetan were larger than in Han at exercise immediately,and less in Han's adolescents during convalescence which formed cross curves. It is suggested that the Tibetan and Han resided at high altitude whose differances of cardiac function had been observed during juvenile stage and indicated that the Tibetan is of better cardiac reserve and adaptative ability to loading when exercise. the cause of above—mentioned results may be to,related to environment of growth development and population inheritance.