不明原因心前区不适患儿心率减速力及心率变异性分析

Analysis of deceleration capacity of rate and heart rate varibility in children with precardial distress of unknown origin

目的：探讨心率减速力（DC）、心率加速力（AC）及心率变异性（HRV）在不明原因心前区不适患儿中的变化。方法56例不明原因心前区不适患儿（患儿组）和63例健康儿童（对照组），年龄6-17岁，行24h动态心电图检查，并对其DC及HRV各项指标进行对比及相关性分析。结果患儿组的DC值小于对照组，AC值大于对照组，心率（HR）大于对照组，差异有统计学意义（P均〈0.05）；患儿与对照组间HRV指标的差异无统计学意义（P〉0.05）。患儿组中，DC与HRV多项指标呈显著正相关（r=0.27-0.40，P均〈0.05），与HR呈显著负相关（r=–0.46，P=0.000）；而AC与HRV多项指标呈显著负相关（r=–0.57-–0.34，P均〈0.05），与HR呈显著正相关（r=0.61，P=0.000）。〈12岁男性患儿HR大于同龄男性对照儿童、相邻RR间期差值的均方根（RMSSD）小于后者；≥12岁男性患儿DC小于、AC大于同龄男性对照儿童；≥12岁女性患儿DC小于同龄女性对照儿童，差异均有统计学意义（P〈0.05）。结论不明原因心前区不适患儿的迷走神经张力降低，DC明显低于正常组，且与HRV多项指标有密切相关性。患儿组DC、HRV性别差异不明显。≥12岁患儿组DC明显低于同龄对照组，提示青春期儿童易发生自主神经功能紊乱。

Objectives To explore the clinical application of deceleration capacity of rate （DC）, acceleration capacity of rate （AC） and heart rate variability （HRV） in children with precardial distress of unknown origin. Methods A total of 56 children with precardial distress of unknown origin and 63 healthy children aged 6 to 17 years were examined by 24 h dynamic elec-trocardiogram, and the indexes of DC and HRV were compared between these two groups. Results DC value of children with precardial distress is less than that of the control group （P〈0.05）, AC value is greater than that of the control group （P〈0.05）, and heat rate （HR） is greater than that of the control group （P〈0.05）. No statistical differences were observed in the indexes of HRV between the two groups. The indexes of DC show a signiifcant positive correlation with HRV in children with precardial distress（r=0.27-0.40, P〈0.05）, while appear a negative relation with HR （r=-0.46, P=0.000）. In contrast, the indexes of AC show a signiifcant negative correlation with HRV （r=-0.57--0.34, P〈0.05）, and appears a positive relation with HR（r=0.61, P=0.000）. HR value is higher in male children less than 12 years old with precardial distress than that of age-matched males in control group, and RMSSD is lower than the latter. DC value of male children more than 12 years with precardial distress is lower than that of age-matched males in control group, while AC value is higher than that of the latter;DC value is signiifcant lower in fe-male children more than 12 yeares with precardial distress than that of age-matched females in the control group （P〈0.05）. Con-clusions The activity of vagus nerve in children with precardial distress of unknown origin is decreased. DC value is signiifcantly lower than that of control group, and shows correlation with indexes of HRV. There is no signiifcant difference in DC and HRV value between male and female children with precardial distress. DC value is lower in children aged 12 or older with precardial distress than that of age-matched children in the control group, which indicates adolescents are vulnerable to autonomic nerve functional disorder.