Institute of Rehabilitation Engineering and Technology, University of Shanghai for Science and Technology, Shanghai 200093, China.
Institute of Rehabilitation Engineering and Technology, University of Shanghai for Science and Technology, Shanghai 200093, China.
J Electrocardiol. 2020 Nov-Dec;63:57-63. doi: 10.1016/j.jelectrocard.2020.10.002. Epub 2020 Oct 11.
Ultra-short-term heart rate variability (HRV) analysis (< 5 min) has been extensively growing in the field of exercise performance for autonomic assessment. However, the validation of ultra-short-term HRV was unclear in the recovery period of exercise. This study aimed to elucidate the agreement between ultra-short-term HRV (0-30 s, 0-1 min, 0-2 min, 0-3 min, 0-4 min) and standard short-term HRV (5 min) and to explore the optimal recording duration under rest and post-exercise conditions.
69 participants were recruited to perform physical exercise on a treadmill with an intensity of 6 km/h, 9 km/h and 12 km/h, independently. The standard deviation of RR-interval (SDNN) and root mean square of successive differences of RR-intervals (RMSSD) were calculated by using ultra-short periods and standard period at rest condition (Pre-E) and three post-exercise trials, i.e., Post-E1, Post-E2 and Post-E3, respectively. One-way ANOVA with repeated-measures and Cohen's d statistics were conducted, and Bland-Altman analysis and interclass correlation coefficients (ICC) were used to assess the levels of agreement.
For SDNN and RMSSD, the results of agreement analysis at rest condition were different from those at post-exercise. At Pre-E, SDNN and RMSSD were reliable for ultra-short-term HRV analysis at all ultra-short periods, i.e., 0-30 s, 0-1 min, 0-2 min, 0-3 min and 0-4 min, with most ICCs greater than 0.9 and Cohen's d showing trivial differences (Cohen's d = 0.024-0.117). However, at post-exercise, SDNN, SDNN, RMSSD and RMSSD showed significant differences with SDNN and RMSSD, respectively (p < 0.01), and the ICCs was not perfect (< 0.9). HRV analysis with time duration longer than 2 min showed nearly perfect reliability in all post-exercise trials, with trivial differences (Cohen's d = -0.003-0.110) and perfect ICCs (ICCs = 0.916-0.998). Furthermore, the limits of the agreement became tighter as the period duration increased in Bland-Altman plots.
This study demonstrated that ultra-short-term HRV analysis was a good surrogate of standard HRV time-domain measures to reflect the autonomic regulation at rest and post-exercise. Specifically, ultra-short-term HRV or HRV was recommended at rest condition, whereas longer than 2 min recording period was reliable to obtain SDNN and RMSSD for the accuracy of HRV analysis.
极短时间心率变异性（HRV）分析（<5 分钟）在运动表现领域的自主评估中得到了广泛应用。然而，在运动恢复期间，极短时间 HRV 的验证尚不清楚。本研究旨在阐明极短时间 HRV（0-30 秒、0-1 分钟、0-2 分钟、0-3 分钟、0-4 分钟）与标准短期 HRV（5 分钟）之间的一致性，并探讨在休息和运动后条件下的最佳记录时长。
招募 69 名参与者在跑步机上以 6、9 和 12 公里/小时的强度进行运动。在休息条件下（Pre-E）和三个运动后试验（Post-E1、Post-E2 和 Post-E3）中，使用极短时间段和标准时间段计算 RR 间期标准差（SDNN）和 RR 间期连续差值的均方根（RMSSD）。采用重复测量的单因素方差分析和 Cohen's d 统计进行分析，采用 Bland-Altman 分析和组内相关系数（ICC）评估一致性水平。
对于 SDNN 和 RMSSD，休息状态下的一致性分析结果与运动后不同。在 Pre-E 时，极短时间段（0-30 秒、0-1 分钟、0-2 分钟、0-3 分钟和 0-4 分钟）的所有极短时间 HRV 分析中，SDNN 和 RMSSD 的结果均可靠，大多数 ICC 大于 0.9，Cohen's d 显示出微小差异（Cohen's d=0.024-0.117）。然而，在运动后，SDNN、SDNN、RMSSD 和 RMSSD 分别与 SDNN 和 RMSSD 存在显著差异（p<0.01），且 ICC 不完美（<0.9）。在所有运动后试验中，时间长度大于 2 分钟的 HRV 分析显示出近乎完美的可靠性，差异微小（Cohen's d=-0.003-0.110），ICC 完美（ICC=0.916-0.998）。此外，Bland-Altman 图中，随着时间段的增加，一致性的界限变得更加严格。
本研究表明，极短时间 HRV 分析是反映休息和运动后自主调节的标准 HRV 时域测量的良好替代方法。具体而言，极短时间 HRV 或 HRV 推荐在休息状态下使用，而记录时间大于 2 分钟可获得准确的 HRV 分析所需的 SDNN 和 RMSSD。
