Perini R, Orizio C, Milesi S, Biancardi L, Baselli G, Veicsteinas A
Dipartimento di Scienze Biomediche e Biotecnologie, Università di Brescia, Italy.
Eur J Appl Physiol Occup Physiol. 1993;66(3):207-13. doi: 10.1007/BF00235095.
The power spectrum analysis of R-R interval variability (RRV) has been estimated by means of an autoregressive method in six men in supine (S) and sitting (C) postures at rest and during steady-state cycle exercise at about 14%, 28%, 45%, 67% of the maximal oxygen consumption (% VO2max). The total power of RRV decreased exponentially as a function of exercise intensity in a similar way in both postures. Three components were recognized in the power spectra: firstly, a high frequency peak (HF), an expression of respiratory arrhythmia, the central frequency (fcentral) of which increased in both S and C from a resting value of about 0.26 Hz to 0.42 Hz at 67% VO2max; secondly, a low frequency peak (LF) related to arterial pressure control, the fcentral of which remained constant at 0.1 Hz in C, whereas in S above 28% VO2max decreased to 0.07 Hz; and thirdly, a very low frequency component (VLF; less than 0.05 Hz, no fcentral). The power of the three components (as a percentage of the total power) depended on the body posture and the metabolic demand. HF% at rest was 30.3 (SEM 6.6) % in S and 5.0 (SEM 0.8) % in C. During exercise HF% decreased by about 30% in S and increased to 19.7 (SEM 5.5) % at 28% VO2max in C. LF% was lower in S than in C at rest [31.6 (SEM 5.7) % vs 44.9 (SEM 6.4) %; P < 0.05], remaining constant up to 28% VO2max.(ABSTRACT TRUNCATED AT 250 WORDS)
采用自回归方法，对6名男性在仰卧位（S）和坐位（C）静息状态以及在约为最大耗氧量（%VO₂max）的14%、28%、45%、67%的稳态循环运动期间的R-R间期变异性（RRV）进行了功率谱分析。在两种姿势下，RRV的总功率均随着运动强度的增加呈指数下降。在功率谱中识别出三个成分：首先，一个高频峰（HF），代表呼吸性心律失常，其中心频率（fcentral）在S和C姿势下均从静息值约0.26Hz增加到67%VO₂max时的0.42Hz；其次，一个低频峰（LF），与动脉血压控制有关，其fcentral在C姿势下保持在0.1Hz不变，而在S姿势下，高于28%VO₂max时降至0.07Hz；第三，一个极低频成分（VLF；小于0.05Hz，无fcentral）。这三个成分的功率（占总功率的百分比）取决于身体姿势和代谢需求。静息时，S姿势下HF%为30.3（标准误6.6）%，C姿势下为5.0（标准误0.8）%。运动期间，S姿势下HF%下降约30%，C姿势下在28%VO₂max时增加到19.7（标准误5.5）%。静息时，S姿势下LF%低于C姿势[31.6（标准误5.7）%对44.9（标准误6.4）%；P<0.05]，直至28%VO₂max时保持不变。（摘要截断于250字）
