探讨不同年龄段儿童无创性心功能检查的正常参考值特点，以及成年人数字心阻抗血流图仪(D-ICG)检查的正常参考值，在儿童的临床应用价值。

选择2015年10月至2016年3月，于四川大学华西第二医院PICU住院治疗后，病情平稳、心功能正常的53例儿童为研究对象。根据53例受试者年龄，将其分为3组，分别为婴儿期组(n＝23，年龄≤1岁)，幼儿及学龄前期组(n＝15，年龄>1～6岁)，学龄期组(n＝15，年龄>6～15岁)。在受试者睡眠或安静配合状态下，应用D-ICG检测其心脏功能，获得30余项参数，统计学比较3组受试者各项参数的差异，并与成年人正常参考值进行比较。总结不同年龄阶段儿童D-ICG检查各参数特点，以及成年人D-ICG正常参考值在儿童的临床应用价值。

①3组受试者心功能指标：每搏作功(SW)、每搏作功指数(SWI)、每分作功(CW)、心脏作功指数(CWI)、每搏量(SV)、心搏指数(SI)、心排血量(CO)及心排血指数(CI)比较，差异均有统计学意义(P<0.001)，且上述指标均随年龄增加而增加。3组受试者基础阻抗(Z₀)和射血分数(EF)比较，差异均无统计学意义(P>0.05)。②3组受试者4项心功能指标前、后负荷参数：心舒张末期容积(EDV)、主动脉顺应性(AC)、总外周阻力(TPR)及总外周阻力指数(TPRI)比较，差异均有统计学意义(P<0.001)，并且EDV及AC均随年龄增加而增加，TPR及TPRI则减少。③收缩功能参数射血前期(PEP)、射血前期指数(PEPI)、心室射血时间(VET)、心室射血时间指数(VETI)、收缩功能指数(PEP/VET)、总电机械收缩期(TEMS)、Q-C间期(Q-C)、心室快速射血指数(C/B-C)、心肌收缩力指数(HI)、室缩波波幅(Cdz/dtmax)，以及舒张功能参数室舒波波幅(Odz/dtmax)、房缩波波幅(WAdz/dtmax)、左室顺应性指标(WA/C)、舒张功能指数(O/C)、等容舒张期(A₂-O)共计15项指标中，PEP、VET、PEP/VET、TEMS、Q-C、Cdz/dtmax及A₂-O 7项心功能指标3组受试者比较，差异均有统计学意义(P<0.05)；其余8项收缩及舒张功能参数3组受试者比较，差异均无统计学意义(P>0.05)。④前述提及的29项心功能指标中，SW、SWI、CW、CWI、SV、SI、CO、CI、EDV、AC、TPR、TPRI、PEP、VET及A₂-O共计15项，仅学龄期组受试者的检测结果在成年人正常参考值范围内；其余14项指标，3组受试者的检测结果均基本在成年人正常参考值范围内。⑤相关性分析结果显示：体表面积(BSA)分别与心功能指标EDV(r＝0.773，P<0.05)，SV(r＝0.843，P<0.05)及CO(r＝0.839，P<0.05)呈高度正相关关系；Cdz/dtmax分别与HI(r＝0.861，P<0.05)及SI(r＝0.536，P<0.05)呈正相关关系；心率分别与PEP(r＝－0.522，P<0.05)，VET(r＝－0.536，P<0.05)，TEMS(r＝－0.815，P<0.05)，Q-C(r＝－0.594，P<0.05)及A₂-O(r＝－0.451，P<0.05)呈负相关关系，心率与PEP/VET(r＝－0.189，P>0.05)无相关关系。

各年龄阶段儿童的心功能指标差异较大。成年人无创性心功能检查的Z₀、大部分的心脏收缩及舒张功能参数正常参考值，基本适用于儿童；但其余指标，则需确立不同年龄段儿童的正常参考值范围。

To analyze the characteristics of normal reference values of noninvasive cardiac function test of children in different age groups, and explore the clinical value of adult normal reference values of digital impedance rheocardiogram (D-ICG) applied to children.

From October 2015 to March 2016, 53 children with stable condition and normal heart function after hospitalized in pediatric intensive care unit (PICU) in West China Second University Hospital, Sichuan University, were selected as study subjects. 53 children were divided into three groups according to age, including infantile group (n=23, age≤1 year old), toddler and preschool group (n=15, age>1-6 years old), school age group (n=15, age>6-15 years old). D-ICG was used to detect heart function of all subjects under sleep, quiet and cooperate condition, about 30 parameters were obtained, and analyzed the differences of these parameters among three groups of children statistically, and compared with the adult normal reference values of these parameters. Summarized the characteristics of D-ICG results of children in different age groups, and the clinical value of apply adult D-ICG normal reference values to children.

① There were significant differences among 3 groups of children in cardiac function parameters including stroke work (SW), stroke work index (SWI), cardiac work (CW), cardiac work index (CWI), stroke volume (SV), stroke index (SI), cardiac output (CO) and cardiac index (CI) (P<0.001), and these parameters increased with age. There were no significant differences among 3 groups in base impedance (Z₀) and ejection fraction (EF) (P>0.05). ② There were significant differences among 3 groups of children in 4 preload and postload parameters including end-diastolic volume (EDV), aortic compliance (AC), total peripheral resistance (TPR) and total peripheral resistance index (TPRI) (P<0.001), and EDV and AC were increased with age, while TPR and TPRI were decreased with age. ③ Systolic function parameters including pre-ejection period (PEP), pre-ejection period index (PEPI), ventricular ejection time (VET), ventricular ejection time index (VETI), systolic function index (PEP/VET), total electromechanical systole (TEMS), Q-C interphase (Q-C), rapid ventricular ejection index (C/B-C), heather index (HI), ventricular amplitude of systolic wave (Cdz/dtmax), and diastolic function parameters including ventricular amplitude of diastolic wave (Odz/dtmax), atrial amplitude of systolic wave (WAdz/dtmax), left ventricular compliance index (WA/C), diastolic function index (O/C), isovolumetric relaxation phase (A₂-O), the results of the comparison among 3 groups of children in all above 15 parameters showed that: there were significant differences among 3 groups of children in 7 cardiac function parameters of PEP, VET, PEP/VET, TEMS, Q-C, Cdz/dtmax and A₂-O (P<0.05). There were no significant differences among 3 groups of children in other 8 systolic and diastolic function parameters (P>0.05). ④A total of 15 in 29 parameters mentioned above including SW, SWI, CW, CWI, SV, SI, CO, CI, EDV, AC, TPR, TPRI, PEP, VET and A₂-O, only the children′s test results of school age group reached the range of adult normal reference values. And the test results of other 14 parameters of 3 groups of children were all in the adult normal reference values range. ⑤ Correlation analysis results showed that: the body surface area (BSA) was positively correlated with EDV (r=0.773, P<0.05), SV (r=0.843, P<0.05) and CO (r=0.839, P<0.05), respectively. Cdz/dtmax was positively correlated with HI (r=0.861, P<0.05) and SI (r=0.536, P<0.05), respectively. Heart rate was negatively correlated with PEP (r=-0.522, P<0.05), VET (r=-0.536, P<0.05), TEMS (r=-0.815, P<0.05), Q-C (r=-0.594, P<0.05) and A₂-O (r=-0.451, P<0.05), respectively. There was no correlation between heart rate and PEP/VET (r=-0.189, P>0.05).

The differences of cardiac function parameters of children were great in different age grades. The basic impedance, most of cardiac systolic and diastolic function parameters of adults normal reference value of noninvasive cardiac function test are generally applicable to children. But normal reference values of other indicators need to be established for children with different ages.