Department of Kinesiology, Mississippi State University, Mississippi, USA.
Am J Phys Med Rehabil. 2010 Oct;89(10):817-23. doi: 10.1097/PHM.0b013e3181f1b6e7.
The aim of this study was to examine whether autonomic modulation of heart rate as measured by heart rate variability and heart rate complexity at rest and during static handgrip exercise differs between individuals with and without paraplegia. This study also examined the relationships between heart rate complexity and heart rate variability parameters.
Heart rate variability and complexity were evaluated in 20 individuals with paraplegia and in 20 individuals without paraplegia during 3 mins of rest and 2 mins of static handgrip exercise at 30% of maximum isometric strength. Spectral decomposition of heart rate variability was used to obtain total power, power in low-frequency and high-frequency ranges, and the ratio of low- to high-frequency power. Heart rate complexity was quantified with sample entropy, a measure of irregularity of the beat-to-beat time series.
Sample entropy was lower (P < 0.05) at rest and during exercise in participants with paraplegia. Total, high-, and low-frequency powers as well as the ratio of low- to high-frequency power did not differ between groups. Sample entropy did not significantly correlate with low- and high-frequency powers or their ratio.
Individuals with paraplegia show lower heart rate complexity at rest and during static exercise. This finding may have implications for cardiovascular morbidity in persons with paraplegia. Heart rate complexity may provide unique information regarding cardiac autonomic modulation, different from that provided by traditional heart rate variability measures.
本研究旨在探讨静息和静态握力运动期间心率变异性和心率复杂度的自主调节在截瘫患者和非截瘫患者之间是否存在差异。本研究还探讨了心率复杂度和心率变异性参数之间的关系。
在 3 分钟的休息和 2 分钟的 30%最大等长强度静态握力运动期间，评估了 20 名截瘫患者和 20 名非截瘫患者的心率变异性和复杂度。心率变异性的频谱分解用于获得总功率、低频和高频范围内的功率以及低频与高频功率的比值。心率复杂度用样本熵来量化，这是衡量逐拍时间序列不规则性的一种方法。
在休息和运动期间，截瘫患者的样本熵较低（P<0.05）。两组之间总功率、高频和低频功率以及低频与高频功率的比值均无差异。样本熵与低频和高频功率及其比值均无显著相关性。
截瘫患者在休息和静态运动期间的心率复杂度较低。这一发现可能对截瘫患者的心血管发病率有影响。心率复杂度可能提供与传统心率变异性测量不同的心脏自主调节的独特信息。
