Chen Hung Yi
Department of Cardiology, Taipei City Hospital-Heping Branch, No. 33, Sec. 2, Zhonghua Rd., Taipei City 100, Taiwan. Email:
Cardiol Res. 2011 Jun;2(3):112-118. doi: 10.4021/cr41w. Epub 2011 May 20.
Heart rate variability (HRV) is an established tool for studying cardiac autonomic activity over time, while heart rate turbulence (HRT) is a recent method used to assess autonomic dysfunction. However, there are different autonomic tones at different times of a day. This study aimed to examine the effect of circadian change of autonomic tone on heart rate turbulence and variability, and determine any relationship between them based on circadian variations.
Twenty-four-hour Holter recordings from 35 subjects with structurally normal heart were done, and HRV and HRT parameters of turbulence onset (TO) and turbulence slope (TS) were calculated. The 24-hour circadian patterns of these parameters and correlation analysis between them were performed.
There were conspicuous diurnal oscillations in TS and HRV parameters, with less prominent variation in TO. TS and high frequency power (HF) shared the similar oscillation patterns in a day. Comparing HRT and HRV based on circadian variation, TS showed positive correlations with HF and low frequency power (LF) to a reasonable degree, while there was an inverse correlation between TS and LF/HF.
Circadian change of TS values throughout the day is more prominent than TO. It also presents as an autonomic activity more than TO. The relationships between HRV and HRT persist independently on the time of a day.
心率变异性（HRV）是研究心脏自主神经活动随时间变化的既定工具，而心率震荡（HRT）是一种用于评估自主神经功能障碍的新方法。然而，一天中不同时间的自主神经张力不同。本研究旨在探讨自主神经张力的昼夜变化对心率震荡和变异性的影响，并根据昼夜变化确定它们之间的关系。
对35名心脏结构正常的受试者进行24小时动态心电图记录，计算心率变异性和心率震荡参数中的震荡起始（TO）和震荡斜率（TS）。对这些参数的24小时昼夜模式及其之间的相关性进行分析。
TS和心率变异性参数存在明显的昼夜振荡，TO的变化不太明显。TS和高频功率（HF）在一天中具有相似的振荡模式。基于昼夜变化比较心率震荡和心率变异性，TS与HF和低频功率（LF）在一定程度上呈正相关，而TS与LF/HF呈负相关。
TS值在一天中的昼夜变化比TO更明显。它也比TO更表现为一种自主神经活动。心率变异性和心率震荡之间的关系在一天中的不同时间独立存在。
