富氧对海拔3700m高原人体运动心力储备的影响

目的　探讨富氧对高原人体运动心力储备方面的影响。方法　对海拔 3 70 0m高原的 1 2名健康青年富氧 (氧浓度为 2 4%～ 2 5 %)前后分别进行踏阶运动 ,采用心力监护仪采集和记录心动周期和心力信息 ,把完成规定运动量运动后第一心音 (S1 )幅值对安静时S1 幅值增加的相应倍数评估心肌收缩能力储备指数 (CCRI) ;利用舒张期和收缩期时限数据计算舒张期 /收缩期比值 (D/S比 )。结果　运动后较安静时HR ,D/S ,S1 幅值均增高 ,有非常显著性差异 (P <0 .0 1 ) ;富氧运动较未富氧运动CCRI,D/S ,S1 幅值增高 ,有显著性差异 (P <0 .0 5 ) ,HR无统计学意义 (P >0 .0 5 )。结论　高原低氧环境下心脏储备主要是心肌收缩能力储备而不是心率储备。富氧对增强机体心力储备具有重要作用

The Effect of Oxygen Enrichment on Human Cardiac Reserve in Exercise at 3 700 m Plateau

Objective To investigate the effect of oxygen enrichment on human cardiac reserve in exercise. Methods 12 healthy youths undertook step test pre and post oxygen enrichment (oxygen concentration was 24%～25%) respectively at 3 700 m. Use cardiac contractility monitor to collect and record the signals of cardiac cycle and cardiac contractility, the increase of the amplitude of the first heart sound after accomplishing the whole exercise workload, with respect to the amplitude of the first heart sound recorded at rest was defined as cardiac contractility reserve index (CCRI ). The ratio of diastolic phase duration to systolic phase duration (D/S) was calculated from the time records obtained. Results HR, D/S and S 1 all increased after exercises and have very significant differences ( P <0.01); CCRI, D/S and S 1 increased after exercise post-oxygen enrichment comparing to pre oxygen enrichment and have significant differences ( P <0.05), but HR had no statistics significance ( P >0.05). Conclusion The cardiac reserve at high altitude is mainly cardiac contractility reserve rather than heart rate reserve. Oxygen enrichment has very important effects on increasing human cardiac reserve.