Roach Daniel, Sheldon Robert
Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Canada.
Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Canada.
J Electrocardiol. 2018 May-Jun;51(3):422-427. doi: 10.1016/j.jelectrocard.2018.02.008. Epub 2018 Feb 20.
We hypothesized that heart period (HP) variability in the low frequency (LF) band is due to transient fluctuations of about 10 s in HP sequences, associated with fluctuations in blood pressure.
10 healthy subjects, mean age 36 y, had HP and blood pressure acquired for 10 min each. Nonrandom HP fluctuations (ripples) lasting 6.7-20 s were detected using time-scrambled surrogate sequences as controls.
Ripples were 99 ± 40 ms in amplitude, in concatenates 23.4 ± 7.4 s long. They co-occurred with similar blood pressure ripples with amplitudes 5 ± 5 mm Hg, correlating with them with r = 0.68 ± 0.10, slope 23.9 ± 10.8 ms/mm Hg, at an optimum lag of 2.16 ± 0.63 beats. A second HP structure consisting of transient tachycardias of 140 ± 53 ms lasting 15.1 ± 6.1 occurred singly. Together the two structures contributed 84% ± 8% of the total power in the LF band.
The LF band is caused by two types of HP structures that occur at discrete times.
我们假设低频（LF）波段的心动周期（HP）变异性是由于HP序列中约10秒的短暂波动，这与血压波动有关。
10名健康受试者，平均年龄36岁，每人采集10分钟的HP和血压数据。使用时间扰乱的替代序列作为对照，检测持续6.7 - 20秒的非随机HP波动（涟漪）。
涟漪的幅度为99±40毫秒，串联长度为23.4±7.4秒。它们与幅度为5±5毫米汞柱的类似血压涟漪同时出现，与血压涟漪的相关性为r = 0.68±0.10，斜率为23.9±10.8毫秒/毫米汞柱，最佳延迟为2.16±0.63个心动周期。第二种HP结构由持续15.1±6.1秒、幅度为140±53毫秒的短暂心动过速组成，单独出现。这两种结构共同贡献了LF波段总功率的84%±8%。
LF波段由两种在不同时间出现的HP结构引起。
