探讨良性和恶性室性早搏(VPB)儿童及健康儿童动态心电图的心率变异性(HRV)，分析各时域指标和频域指标值变化。

选择2012年1月至2017年12月，于四川大学华西第二医院接受动态心电图检查，根据临床辅助检查和随访结果明确病因的6～14岁VPB儿童100例为研究对象。按照VPB的良、恶性，将其分为恶性VPB组(n＝50)及良性VPB组(n＝50)。恶性VPB组患儿均为合并器质性心脏病的VPB患儿，其中合并先天性心脏病患儿为4例、扩张型心肌病(DCM)为9例、心肌酶学检查结果异常而被诊断为病毒性心肌炎患儿为37例。选取同期于同一家医院接受动态心电图检查未见异常，并且一般临床资料均显示正常的儿童50例，纳入对照组。对于呈正态分布与方差齐性计量资料，如总体标准差(SDNN)、均值标准差(SDANN)、差值均方根(rMSSD)、差值>50 ms的百分比(PNN50)、R-R间期变异系数(CV)，超低频功率(ULF)、极低频功率(VLF)、低频功率(LF)及高频功率(HF)，采用±s表示，3组比较，采用单因素方差分析；进一步组间两两比较，采用最小显著差异法(LSD)法。受试儿性别构成比等计数资料采取率(%)表示，3组间比较，采用χ²检验。3组受试儿的性别构成比及年龄比较，差异均无统计学意义(P>0.05)。本研究符合2013年修订的《世界医学协会赫尔辛基宣言》要求，分组征得受试儿监护人的知情同意，并与之签署临床研究知情同意书。

3组受试儿的HRV时域指标SDNN、SDANN、rMSSD、PNN50、CV，频域指标ULF、VLF、LF、HF分别整体比较，差异均有统计学意义(F＝42.304、14.144、26.344、15.362、8.115，18.031、10.611、20.928、13.719, P<0.05)。进一步进行3组间两两比较的结果显示，恶性VPB组与良性VPB组CV、VLF、LF比较，差异均无统计学意义(P>0.05)；良性VPB组与对照组PNN50、HF比较，差异均无统计学意义(P>0.05)；其余HRV时域、频域指标3组间两两比较，差异均有统计学意义(P<0.05)。

儿童VPB的动态心电图HRV分析，对临床判断良、恶性VPB具有一定价值，但是否可作为判断儿童VPB严重程度及其预后的指标，则有待多中心、大样本、前瞻性随机对照试验进一步研究、证实。

To explore the heart rate variability (HRV) of dynamic electrocardiogram in children with benign or malignant ventricular premature beat (VPB) and healthy children, and analyze the changes of time and frequency domain indexes of HRV.

From January 2012 to December 2017, a total of 100 children with VPB diagnosed by auxiliary examinations and follow-up visits results, who were 6-14 years old and accepted dynamic electrocardiogram test in West China Second University Hospital, Sichuan University were recruited in this study. According to benign or malignant VPB, they were divided into benign VPB group (n=50) and malignant VPB group (n=50). Children in malignant VPB group were all combined with organic heart diseases, such as congenital heart defects (4 cases), dilated cardiomyopathy (DCM) (9 cases ), and viral myocarditis (37 cases) diagnosed by abnormal myocardial enzyme levels. Meanwhile, 50 cases of healthy children with the same age range who received dynamic electrocardiogram in the same hospital during the same period and the results were normal were included into control group. Measurement data with normal distribution and homogeneity such as standard deviation of all normal-to-normal intervals (SDNN), standard deviation of average normal-to-normal intervals (SDANN), root mean square of the successive difference (rMSSD), percentage normal-to-normal interval deviation greater than 50 ms (PNN50), coefficient of variance (CV), coefficient of variance (ULF), very-low frequencies (VLF), low frequencies (LF), and high frequencies (HF) were expressed by ±s. And those data among 3 groups were compared by one-way ANOVA, further comparisons between each two groups were conducted by least singnificant difference (LSD) test. Numeration data such as constituent ratio of genders were expressed by rate (%), and were compared by chi-square test among 3 groups. There were no significant differences among 3 groups in the constituent ratio of gender and age (P>0.05). This study met the requirements of the World Medical Association Declaration of Helsinki revised in 2013. Clinical informed consent was obtained from each child′s guardians.

There were significant differences among 3 groups in HRV analysis results of time domain indicators such as SDNN, SDANN, rMSSD, PNN50, CV, and frequency domain indicators such as ULF, VLF, LF and HF (F=42.304, 14.144, 26.344, 15.362, 8.115, 18.031, 10.611, 20.928, 13.719; P<0.05). There were no significant differences among CV, VLF and LF between malignant VPB group and benign VPB group (P>0.05), and PNN50 and HF between benign VPB group and control group (P>0.05), but there were significant differences in the others time domain indicators and frequency domain indicators of HRV between each two groups (P<0.05).

The HRV analysis of dynamic electrocardiogram is helpful in determining benign and malignant VPB in children. However, prospective randomized controlled trials with multicenter and large-sample size are needed to evaluate whether the HRV analysis can be used to determine the severity of VPB and as a prognosis marker in children with VPB.