Twenty-Four-Hour Heart Rate Is a Trait but Not State Marker for Depression in a Pilot Randomized Controlled Trial With a Single Infusion of Ketamine

A 4-day electrocardiogram (ECG) was recorded for 16 treatment-resistant patients with major depressive disorder (MDD) and 16 age- and sex-matched controls before, and for the patient group only, after a single treatment with the rapid-acting antidepressant ketamine or placebo (clinical trial registration available on https://www.clinicaltrialsregister.eu/ with EUDRACT number 2016-001715-21). Two features were calculated from the ECG signal: the mean
HR and the root mean square of the successive differences (RMSSD) in RR peaks. Both features were calculated in a window of 5min (overlap of 4min). The activity level of the participants was calculated as the standard deviation of the magnitude of acceleration as derived from the accelerometer of the ECG patch. In accordance with the ECG features, activity levels were calculated in windows of 5min with 4-min overlap. A quality indicator based on research published by Orphanidou et al. (2014) was assigned to every 10-s segment of the signal. All 5-min windows with an average QI below 0.8 were excluded. In addition, following Smets et al. (2018) , all segments of high activity (std ACC > 0.04) were excluded as well. Lastly, all retained windows were averaged into either hourly measurements. These hourly measurements are provided in the attached database.

本数据集包含16例难治性重度抑郁症（major depressive disorder, MDD）患者与16例年龄、性别匹配的健康对照者的4天心电图（electrocardiogram, ECG）记录；患者组在接受单次速效抗抑郁药氯胺酮或安慰剂治疗前后均完成数据采集，对照组仅采集治疗前的记录，该临床试验的注册信息可于https://www.clinicaltrialsregister.eu/查询，欧盟临床试验注册编号为EUDRACT 2016-001715-21。从该ECG信号中提取两项特征：平均心率（mean HR）以及RR间期峰值间连续差值的均方根（root mean square of the successive differences, RMSSD），两项特征均通过5分钟滑动窗口（窗口重叠时长为4分钟）计算得到。参与者的活动水平则通过ECG贴片内置加速度计所采集的加速度幅值的标准差计算，其窗口计算规则与ECG特征一致，即采用5分钟滑动窗口且重叠时长为4分钟。参考Orphanidou等人2014年发表的研究方法，为每10秒的信号片段分配质量指标（quality indicator, QI）；所有平均质量指标低于0.8的5分钟窗口均予以剔除。此外，参照Smets等人2018年的研究标准，加速度标准差大于0.04的高活动度片段同样被排除。最终，所有保留的窗口数据均被整合为每小时一次的测量值，该类每小时汇总的测量数据已随附于本数据库中。