北京地区3~12岁920名儿童心率变异性分层随机抽样调查分析

摘要 目的 测定920名3～12岁儿童心率变异性（HRV）时域指标值范围；明确HRV与年龄、性别的相关性；研究无症状期前收缩和QT延长儿童HRV的变化。方法 920名3～12岁儿童分为学龄前期组（3～6岁，274名)、学龄期组（～10岁，365名)、青春前期组（～12岁，281名)，行24 h HRV时域分析；进行各年龄组、性别HRV的方差分析；室性期前收缩按照Lown分级法分成4组，QT延长以QTc>450 ms为界分成正常和延长2组，分别进行组间HRV的方差分析。结果 ①HRV各时域指标值随年龄增长而增高，各年龄组均数间差异有统计学意义（P<0.01）。②按性别分组比较HRV 5项时域指标值，男性高于女性，总体标准差（SDNN）、均值标准差（SDANN）和标准差均值（SDNNINX）3项指标均数差异有统计学意义（P<0.05），学龄期和青春前期组SDNN、SDANN均数的男、女间差异有统计学意义（P<0.01），差值均方的平方根（RMSSD）和差值>50 ms的百分比（PNN50）均数差异无统计学意义（P>0.05）。③无期前收缩组与无症状偶发期前收缩组、频发期前收缩组和病理性期前收缩组HRV时域指标值差异无统计学意义（P>0.05）。④QT间期正常组和延长组HRV时域指标值差异无统计学意义（P>0.05）。结论 ①儿童HRV存在年龄差异。HRV的时域指标值随年龄增长而增加，提示儿童心脏自主神经系统发育尚不成熟，交感神经和迷走神经随年龄的增长发育渐趋完善和平衡。②学龄前期至青春前期，HRV男性高于女性。提示心脏自主神经总张力男性高于女性，男性心交感神经张力较女性相对增高；而心迷走神经张力男、女间差异无统计学意义，男、女心脏迷走神经功能发育可能较一致。青春期前，男、女间HRV的差异最为显著。可能提示此年龄段男、女间心脏自主神经发育的不一致性。③无症状期前收缩及QT间期延长儿童的HRV与其他儿童HRV相比无明显变化。

Analysis of heart rate varibility of healthy children from 3 to 12 years old in Beijing

Objective To investigate the normal range of the time-domain index of heart rate varibility (HRV) in 920 healthy children aged from 3 to 12 years old, explore the correlation between HRV and age or sex, and study the changes of HRV in children with asymptomatic ventricular premature contraction and long QT interval. Methods 920 healthy children were randomly divided into three groups according to their ages as follows: group I (n=274), 3 to 6 years old; group Ⅱ(n=365), 7 to 10 years old; group Ⅲ(n=281), 11 to 12 years old. The organic heart diseases or other chronic diseases were excluded depending on case history and physical examination or x-ray. Routine ECG at body surface and Holter were used to record the HRV. Five time-domain indexes of HRV were recorded for 24 hours. The relationship between age or sex and HRV was analysed. The difference of HRV between normal children and asymptomatic children with ventricular premature contraction or with long QT interval (QTc >450 ms) was compared. Children with ventricular premature contraction were divided into four groups according to Lown classification as follows: grade 0, normal children without any types of arrhythmia; grade 1, abiogenetic premature contraction (<30 beats/hour); grade 2, frequent premature contraction (≥30 beats/hour); ≥grade 3, pathological ventricular premature contraction. Results The normal ranges of HRV in children of three age categories were obtained. ① The five time-domain indexes (SDNN, SDANN, SDNNIDX, PNN50 and RMSSD) of children were different from those of adults.② Among the five time-domain indexes, SDNN, SDANN and SDNNID were increased with age, while PNN50 and RMSSD showed a decreasing trend of group Ⅱand group Ⅲ. ③ There were significant differences in the five time domain indexes among three age groups (P<0.01).④ The five time domain indexes of HRV were higher in males than in females. The comparison showed significant differences in SDNN, SDANN and SDNNIDX between male and female (P<0.05), but no differences were found in PNN50 and RMSSD. The comparison within each age group showed significant differences in SDNN and SDANN between male and female in group Ⅱ and groupⅢ, but no difference in group I. ⑤ No significant differences were found in five time-domain indexes between normal children and asymptomatic children with ventricular permature contraction. ⑥ Similarly, no significant differences were found in five time-domain indexes between normal children and asymptomatic children with long QT interval. Conclusions ① HRV was increased with age in children; ② There was significant difference in HRV between male and female in each age stage, suggesting the variance in the development of autonomic nervous system between male and female; ③ There was no difference in HRV between normal children and asymptomatic children with ventricular permature contraction or long QT interval, suggesting no difference in tensity of autonomic nervous system between normal children and asymptomatic children with arrhythmia. Analysis of HRV may be a useful method of monitoring the occurance of hazardous arrhythmia.