正常人群的心率变异性分析

将１００４例正常人分三个年龄组进行短程（５ｍｉｎ）心率变异性（ＨＲＶ）分析。时域法的参数为平均心率标准差（ＨＲＳＤ），连续５ｍｉｎ节段平均正常ＲＲ间期标准差（ＳＤＡＮＮ），相邻ＲＲ间期差的均方根（ｒＭＳＳＤ），相邻ＲＲ间期差异≥５０ｍｓ的百分数（ＰＮＮ_（５０））；频域法的参数为极低频（ＶＬＦ）、低频（ＬＦ）、高频（ＨＦ）成分，总功率（ＴＰ）及ＬＦ／ＨＦ比值。各指标间做相关分析。结果：４５岁以上组ＨＲＳＤ、ＳＤＡＮＮ、ｒＭＳＳＤ、ＰＮＮ_（５０）、ＶＬＦ、ＬＦ、ＨＦ、ＴＰ均低于４５岁以下两组（Ｐ＜０．０５或＜０．０１）。ＳＤＡＮＮ、ｒＭＳＳＤ、ＰＮＮ_（５０）与ＨＦ呈高度正相关（ｒ＞０．７０，Ｐ＜０．０００１），其中以ＳＤＡＮＮ、ＰＮＮ_（５０）相关更好（ｒ＞０．７５，Ｐ＜０．００１），ＳＤＡＮＮ、ｒＭＳＳＤ、ＰＮＮ_（５０）间高度相关（ｒ＞０．８０，Ｐ＜０．０００１）。不同性别ＨＲＶ各参数相比无显著差异。提示：ＨＲＶ随年龄的增长而下降，以迷走神经张力下降为主；各指标中以ＳＤＡＮＮ、ｒＭＳＳＤ、ＰＮＮ_（５０）、ＨＦ能更好地反映迷走神经张力变化。

Heart Rate Variability in Normal Persons

Heart rate variability(HRV)was analyzed in 1 004 normal persons who were subdivided by age into three groups. Using short-term(5 minutes)time and frequency domain measures of HRV,standard deviation of heart rate in beats/min(HRSD),standard deviation of the mean of all 5 minutes segments of normal RR intervals(SDANN),percent of difference between adjacent normal RR intervals that was longer than or equal to 50 ms (PNN50),root mean square successive difference between adjacent normal RR intervals(rMSSD),very low frequency(VLF),low frequency(LF),high frequency(HF),total power(TP) and the ratio of low to high (LF/HF)were calculated and correlation between the indices of HRV were analyzed.The results showed that HRSD,SDANN,PNN50,rMSSD,VLF,LF, HF,TP were lower in>45 years group than that in <45 years group (P<0.05 or 0.01);HF was correlated positively with SDANN,PNN50 and rMSSD(r>0.7,P<0. 0001);There was strongly correlation between SDANN,PNN50 and rMSSD(r>0.8,P<0. 0001); There was no significant relation between gender and HRV.Thus,the study suggests that HRV decreases with age; SDANN,PNN50,rMSSD and HF are better indices that reflect vagal nervous activity than the others.