The Usefulness of the Coefficient of Variation of Electrocardiographic RR Interval as an Index of Cardiovascular Function and its Correlation with Age and Stroke

年齡與腦血管疾病對心律變異係數的影響

張家齊(Chia-Chi Chang) ； 蕭子健(Tzu-Chien Hsiao) ； 江怡穎(Yi-Ying Chiang) ； 許弘毅(Hung-Yi Hsu)

《童綜合醫學雜誌》 6卷2期 (2012/12) Pp. 41-48

https://doi.org/10.29838/TMJ.201212.0001

摘要

心跳時間區間的變異係數（CV of RRI）由心跳區間的標準差除以其均值而得。其數值代表的特性近似於心律變異度，並且加入個體標準化的計算。本研究目的在於探討CV of RRI於評估新血管系統功能的可行性。本研究採31位健康受試者與25位缺血性腦中風的病人，探討，比較其CV of RRI 、心律標準差（SDNN）、壓感反射敏感度（BRS）於10分鐘平躺休息與傾斜床試驗的變化，BRS的計算採用時序分析法。結果顯示，健康受試者的CV of RRI、SDNN、BRS與年齡呈顯著負相關在平躺休息狀態（r= -0.526,-0.731, -0.637）及傾斜床試驗（r= -0.785, -0.697, -0.703），而缺血性腦中風病人的CV of RRI, SDNN, BRS並無顯著相關性。而CV of RRI, SDNN, BRS 在健康受試者與缺血性腦中風病人均有顯著的不同。CV of RRI可由簡單的醫療設備量測取得並在心血管系統功能評估上有潛力。而年齡的衰退現象均呈現於CV of RRI, SDNN, BRS中。

關鍵字

變異係數 ； 心跳變異性 ； 感壓反射敏感度 ； 缺血性腦中風

並列摘要

The coefficient of variation (CV) of the time interval between two consecutive R-waves, also known as the RR interval (RRI), is calculated by dividing the standard deviation of RRI (SDNN) by the mean of RRI. CV of RRI is similar to heart rate variability in terms of individual normalization. The purpose of this study was to evaluate the validity of CV of RRI as an index of cardiovascular function and its correlation with age and stroke. CV of RRI, SDNN, and baroreflex sensitivity (BRS) were evaluated in 31 healthy controls and 25 patients who had suffered ischemic stroke. Resting electrocardiography and arterial blood pressure were recorded for 10 min, once in the supine position in all recruited subjects and once in the head-up tilt position in the controls. BRS was measured using the spontaneous sequence analysis method.In the healthy controls, CV of RRI, SDNN, and BRS recorded in both the supine (r = −0.526, −0.731, and −0.637, respectively; all p ＜ 0.01) and head-up tilt positions (r = −0.785, −0.697, and −0.703, respectively; all p ＜ 0.01) were negatively correlated with age. In contrast, no correlation was found between these indices and age in the stroke patients. Significant correlations were found among CV of RRI, SDNN, and BRS in both the healthy controls and stroke patients (all p ＜ 0.01). In conclusion, CV of RRI measured using simple medical devices may be a potentially useful indicator of cardiovascular function in both healthy individuals and stroke patients. Aging is associated with a decline in SDNN, BRS, and CV of RRI in healthy individuals.

並列關鍵字

Coefficient of variation ； Heart rate variability ； Baroreflex sensitivity ； Ischemic stroke