Fluctuations in autonomic cardiovascular regulation during exposure to high altitude may increase the risk of heart attack during waking and sleep. This study compared heart rate variability (HVR) and its components d...Fluctuations in autonomic cardiovascular regulation during exposure to high altitude may increase the risk of heart attack during waking and sleep. This study compared heart rate variability (HVR) and its components during sleep at low altitude and after 30 - 41 hours of acclimatization at high altitude (3480 m) in five mountain marathon runners controlled for diet, drugs, light-dark cycle and jet lag. In comparison to sea level, RR-intervals during sleep at high altitude decreased significantly (P 0.001). The significant increase in sympathetic autonomic cardiovascular modulation at high altitude protects against excessive oxygen deprivation during sleep. Increases in R-R intervals can require longer periods of acclimatization at3480 m to mitigate the effects of altitude/hypoxia on sympathetic tone, thus reducing cardiovascular distress at rest during waking and sleep and probably before during and after athletic performance at altitude.展开更多
讨论了外延及注入制作的薄层 Ga As Hall器件如何获得高的磁线性度 .Ga As Hall器件的磁线性度在高磁场下会有偏离 ,但可以通过外延及注入的过渡层对有源区进行补偿 ,在合适的有源区和过渡区的浓度和厚度分布中 ,可以得到在 2 .5 T的强...讨论了外延及注入制作的薄层 Ga As Hall器件如何获得高的磁线性度 .Ga As Hall器件的磁线性度在高磁场下会有偏离 ,但可以通过外延及注入的过渡层对有源区进行补偿 ,在合适的有源区和过渡区的浓度和厚度分布中 ,可以得到在 2 .5 T的强磁场下 ,± 0 .0 4展开更多
文摘Fluctuations in autonomic cardiovascular regulation during exposure to high altitude may increase the risk of heart attack during waking and sleep. This study compared heart rate variability (HVR) and its components during sleep at low altitude and after 30 - 41 hours of acclimatization at high altitude (3480 m) in five mountain marathon runners controlled for diet, drugs, light-dark cycle and jet lag. In comparison to sea level, RR-intervals during sleep at high altitude decreased significantly (P 0.001). The significant increase in sympathetic autonomic cardiovascular modulation at high altitude protects against excessive oxygen deprivation during sleep. Increases in R-R intervals can require longer periods of acclimatization at3480 m to mitigate the effects of altitude/hypoxia on sympathetic tone, thus reducing cardiovascular distress at rest during waking and sleep and probably before during and after athletic performance at altitude.
