Background

Traditional electrocardiography (ECG)-derived heart rate variability (HRV) and photoplethysmography (PPG)-derived “HRV” (termed PRV) have been reported interchangeably. Any potential dissociation between HRV and PRV could be due to the variability in pulse arrival time (PAT; time between heartbeat and peripheral pulse).

Objective

This study examined if PRV is equivalent to ECG-derived HRV and if PRV’s innate error makes it a high-quality measurement separate from HRV.

Methods

ECG data from 1084 subjects were obtained from the PhysioNet Autonomic Aging dataset, and individual PAT dispersions for both the wrist (n = 42) and finger (n = 49) were derived from Mol et al. (Exp Gerontol. 2020; 135: 110938). A Bayesian simulation was constructed whereby the individual arrival times of the PPG wave were calculated by placing a Gaussian prior on the individual QRS-wave timings of each ECG series. The standard deviation (σ) of the prior corresponds to the PAT dispersion from Mol et al. This was simulated 10,000 times for each PAT σ. The root mean square of successive differences (RMSSD) and standard deviation of N–N intervals (SDNN) were calculated for both HRV and PRV. The Region of Practical Equivalence bounds (ROPE) were set a priori at ± 0.2% of true HRV. The highest density interval (HDI) width, encompassing 95% of the posterior distribution, was calculated for each PAT σ.

Results

The lowest PAT σ (2.0 SD) corresponded to 88.4% within ROPE for SDNN and 21.4% for RMSSD. As the σ of PAT increases, the equivalence of PRV and HRV decreases for both SDNN and RMSSD. The HDI interval width increases with increasing PAT σ, with the HDI width increasing at a higher rate for RMSSD than SDNN.

Conclusions

For individuals with greater PAT variability, PRV is not a surrogate for HRV. When considering PRV as a unique biometric measure, SDNN may have more favorable measurement properties than RMSSD, though both exhibit a non-uniform measurement error.

中文翻译：

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基于光电体积描记图的可穿戴心率变异测量方法是否等同于心电图？模拟研究

 背景

传统心电图 (ECG) 衍生的心率变异性 (HRV) 和光电体积描记 (PPG) 衍生的“HRV”（称为 PRV）已被互换报道。 HRV 和 PRV 之间任何潜在的分离都可能是由于脉搏到达时间（PAT；心跳和外周脉搏之间的时间）的变化造成的。

 客观的

这项研究检验了 PRV 是否等同于心电图得出的 HRV，以及 PRV 的固有误差是否使其成为独立于 HRV 的高质量测量。

 方法

1084 名受试者的心电图数据来自 PhysioNet Autonomic Aging 数据集，手腕 (n = 42) 和手指 (n = 49) 的个人 PAT 离散度来自 Mol 等人。 （Exp Gerontol。2020；135：110938）。构建了贝叶斯模拟，通过在每个 ECG 系列的各个 QRS 波时序上放置高斯先验来计算 PPG 波的各个到达时间。先验的标准差 (σ) 对应于 Mol 等人的 PAT 离散度。每个 PAT σ 都被模拟 10,000 次。计算 HRV 和 PRV 的连续差均方根 (RMSSD) 和 N-N 间隔标准差 (SDNN)。实际等效范围区域 (ROPE) 预先设置为真实 HRV 的 ± 0.2%。计算每个 PAT σ 的最高密度区间 (HDI) 宽度，涵盖后验分布的 95%。

 结果

最低 PAT σ (2.0 SD) 对应于 SDNN 的 ROPE 内的 88.4% 和 RMSSD 的 21.4%。随着 PAT 的 σ 增加，SDNN 和 RMSSD 的 PRV 和 HRV 的等效性降低。 HDI 区间宽度随着 PAT σ 的增加而增加，RMSSD 的 HDI 宽度以比 SDNN 更高的速率增加。

 结论

对于 PAT 变异较大的个体，PRV 不能替代 HRV。当将 PRV 视为一种独特的生物特征测量时，SDNN 可能比 RMSSD 具有更有利的测量特性，尽管两者都表现出不均匀的测量误差。