Individual variation of heart rate variability in Japanese population.

对75例健康日本男性受试者(年龄20~61岁)在站立和仰卧两种姿势下重复测量心率变异性(HRV)频谱成分(4~8次测量，平均6次测量)。分析了低频成分(LF)、高频成分(HF)和平均心率(HR)的个体变异，将个体变异分为个体间变异和个体内变异。计算了InterV和Intra的贡献率和变异系数。站立位和仰卧位对心率的贡献率分别为15.8%和12.9%。站立时HF和LF的Inv%分别为31.5%和26.5%，仰卧位分别为27.8%和35.5%。计算InterV(InterCV)和Intra(Intra CV)系数。站立时HR、HF、LF的变异系数分别为14.9、41.4、48.4%，仰卧位的变异系数分别为16.2、42.9、44.2%。站立时HR、HF和LF的变异系数分别为5.0%、19.7%和21.2%，仰卧位的变异系数分别为4.7%、20.1%和23.0%。我们还计算了对数变换的HRV指数的InterV和Intra。对数变换显著减少了这两个变量：变异系数为14-16%，变异系数为6-7%。虽然室间变异相当大，但心率变异性的室内变异可以忽略不计。心率无明显变化，但心率变异性指数随年龄增长而降低。测定系数(r^2)为14~34%。在对数变换的HRV指标中，决定系数为9-15%，表明观察到的InterV的14-34%(原始)或9-15%(对数)可能是由于年龄的变化。

Spectral components of heart rate variability (HRV) were repeatedly measured (4-8 measurements; mean: 6 measurements) in 75 healthy Japanese male subjects (age range:20-61) under two postural conditions (standing and supine). Low-frequency (LF) and high-frequency (HF) components and mean heart rate (HR) were analyzed with special reference to individual variations, which were classified into two types : inter-(interV) and intra-individual variations (intraV). The percent contributions and coefficients of variations were calculated for both interV and intraV. Percent contributions of intraV (intraV%) of HR with standing and supine postures were 15.8 and 12.9%, respectively. The intraV% of HF and LF on standing were 31.5 and 26.5%, while those in the supine posture were 27.8 and 35.5%, respectively. The coefficients of interV (interCV) and intraV (intraCV) were also calculated. The interCVs of HR,HF, and LF on standing were 14.9,41.4,nd 48.4%, while those in the supine posture registered 16.2,42.9,and 44.2%, respectively. The intraCVs of HR, HF, and LF on standing were 5.0, 19.7, and 21.2%, while those in the supine posture indicated 4.7, 20.1, and 23.0%, respectively. We also calculated the interV and intraV of logarithmic-transformed HRV indexes. The log-transformation remarkably diminished both variables: interCV and intraCV registered 14-16 and 6-7%, respectively. Although interV variations were considerabley large, intraV variations of HRV were negligibley small. The HRV indexes decreased with age, although HR remained unchanged. The coefficients of determination (r^2) were 14-34%. In the case of log-transformed HRV indexes, the coefficients of determination registered 9-15%, suggesting that 14-34% (raw) or 9-15% (log) of the observed interV may be due to variations in age.