Lkhagva L
Kosm Biol Aviakosm Med. 1984 Mar-Apr;18(2):60-3.
The study of diurnal variations of heart rate of 7 healthy volunteers exposed to head-down tilting (-8 degrees) demonstrated that the absolute value decreased at the peak phase and in the daytime and increased at night; the amplitude of the diurnal variations declined. The experimental data indicate that heart rate may decrease in the morning and in the daytime beginning with the first days of the head-down position. Sometimes this decrease may be delayed and develop on head-down days 7-12.
对7名健康志愿者进行头低位倾斜（-8度）时心率昼夜变化的研究表明，在峰值阶段和白天绝对值降低，而在夜间升高；昼夜变化幅度减小。实验数据表明，从处于头低位的第一天开始，心率可能在早晨和白天降低。有时这种降低可能会延迟，并在头低位第7至12天出现。
