心音信号分析正常、足月新生儿出生早期的心力储备

Evaluation of cardiac contractility reserve in normal and full term early newborns based on the heart sound signal analysis

目的采用心音图运动试验(PCGET)检测和评估正常、足月新生儿出生早期(0~7d)的心力储备(CCR)。方法选择2013年1月1日至2015年1月1日,于成都市妇女儿童中心医院产科住院分娩的1 797例正常、足月的出生早期新生儿为研究对象。根据其出生后不同日龄,将其分为0~7d组(n=192、257、270、214、232、212、210、210)。采用前瞻性研究方法,检测和分析这些新生儿的第一心音(S1)与第二心音(S2)的幅值比值(S1/S2)、心脏舒张期时限(D)与收缩期时限(S)的比值(D/S)和应激后心力变化趋势(CCCTS)。采用Kruskal-Wallis H秩和检验,对8组新生儿安静时和哭泣后的S1/S2,哭泣后的CCCTS分别进行整体比较及组间两两比较。采用方差分析,对8组新生儿安静时和哭泣后的D/S分别进行整体比较,采用最小显著性差异(LSD)法进一步进行组间两两比较。采用配对设计的Wilcoxon符号秩和检验,对8组新生儿安静时和哭泣后的S1/S2进行组内比较;采用配对t检验,对8组新生儿安静时和哭泣后的D/S进行组内比较。采用Spearman秩相关性分析,对这些新生儿安静时的S1/S2与D/S相关性进行分析。采用多重线性逐步回归分析,对纳入研究新生儿安静时D/S的影响因素进行分析。本研究遵循的程序符合成都市妇女儿童中心医院人体试验委员会制定的伦理学标准,得到该委员会批准,分组征得受试儿监护人知情同意,并与监护人签署临床研究知情同意书。结果 (1)8组正常、足月的出生早期新生儿安静时的S1/S2整体比较,差异有统计学意义(χ~2=847.5,P<0.001),进一步进行组间两两比较的结果显示,0d组的S1/S2显著低于1d和2d组,但是显著高于其余5组,并且差异均有统计学意义(P<0.05);1d组的S1/S2显著高于其余7组,并且差异亦均有统计学意义(P<0.05);2~7d组的S1/S2呈逐渐下降趋势,这6组的S1/S2两两比较,差异均有统计学意义(P<0.05)。(2)8组新生儿安静时的D/S整体比较,差异有统计学意义(F=15.6,P<0.001)。进一步进行组间两两比较的结果显示,0d组的D/S显著低于其余7组,并且差异均有统计学意义(P<0.05);1d组的D/S高于0d组,但是显著低于其余6组,差异亦均有统计学意义(P<0.05);2~7d组的D/S组间两两比较,差异均无统计学意义(P>0.05)。(3)8组新生儿哭泣后的S1/S2整体比较,差异有统计学意义(χ~2=7.8,P<0.001),进一步进行组间两两比较的结果显示,0~2d组的S1/S2组间两两比较,差异均无统计学意义(P>0.05),但是0~2d组的S1/S2均显著低于3~7d组,并且差异均有统计学意义(P<0.05)。(4)8组新生儿哭泣后的D/S和CCCTS分别整体比较,差异均有统计学意义(F=3.2,P=0.002;χ~2=8.9,P<0.001)。对D/S和CCCTS进行组间两两比较的结果显示,0d组均显著低于其余7组,并且差异均有统计学意义(P<0.05);但是其余7组组间分别两两比较,差异均无统计学意义(P>0.05)。(5)0d组新生儿安静时和哭泣后的S1/S2组内比较,差异无统计学意义(P>0.05);但是其余7组则显著低于同组新生儿哭泣后的S1/S2,并且差异均有统计学意义(P<0.001)。(6)8组新生儿安静时的D/S均显著高于组内新生儿哭泣后的D/S,并且差异均有统计学意义(P<0.001)。(7)纳入研究新生儿安静时的S1/S2与D/S呈负相关关系(r_s=-0.1,P<0.001)。(8)对纳入研究新生儿安静时D/S的影响因素进行多重线性逐步回归分析的结果显示,新生儿日龄越大、母亲孕次越少及新生儿性别为男性,其安静时的D/S越大。(9)本研究根据新生儿PCGET检测结果,计算出不同日龄正常、足月的出生早期新生儿安静时和哭泣后的CCR各项指标95%参考值范围。结论通过PCGET检测建立正常、足月的出生早期新生儿CCR评估体系,或许可为我国针对这类新生儿的心脏保健,提供理论依据。

Objective To measure and evaluate the cardiac contractility reserve（CCR）in normal and full term early newborns with 0-7-day age by phonocardiogram exercise test（PCGET）.Methods From January 1,2013 to January 1,2015,a total of 1 797 normal and full term early newborns were included into this study.They were classified into eight groups（0-7 dgroups）according to the day-age（n=192,257,270,214,232,212,210,210）.The ratio of the amplitude of the first heart sound and the amplitude of the second heart sound（S1/S2）,the ratio of diastolic to systolic duration（D/S）and cardiac contractility change trend after stimulation（CCCTS）of these newborns all were measured and analyzed by perspective research method.The S1/S2 in quiet state and after crying and CCCTS after crying among 8 groups were compared by Kruskal-Wallis H rank test.The D/Sin quiet state and after crying among 8 groups were compared by one-way ANOVA analysis,and least-significant difference（LSD）method was used to further comparison between different groups.The S1/S2 in quite state and after crying of each group was compared by Wilcoxon signed-rank test.The D/Sin quite state and after crying of each group was compared by pairedsamples t test.The relationship between S1/S2 and D/Sin quite state was analyzed by Spearman rank correlation.Besides,the influencing factors of D/Sin quite state were conducted by multiple linear stepwise regression.The study protocol was approved by the Ethical Review Board of Investigation in Human Beings of Chengdu Women′s and Children′s Central Hospital.Informed consent was obtained from participants′guardians.Results（1） There was statistically significant difference in S1/S2 among8 groups in quite state（χ~2=847.5,P〈0.001）.Multiple comparison results showed the following results.The S1/S2 in 0 dgroup was lower than that of 1 dgroup and 2 dgroup,but higher than those of the other 5 groups,and all the differences were statistically significant（P〈0.05）.The S1/S2 in 1 dgroup was higher than those of the other 7 groups,and all the differences were statistically significant（P〈0.05）.And S1/S2 gradually decreased among 2-7 dgroups,and all the differences among those 6 groups were statistically significant（P〈0.05）.（2） There was statistically significant difference in D/S among 8 groups in quite state（F =15.6,P〈0.001）. Multiple comparison results showed the following results.The D/Sin 0 dgroup was significantly lower than those of the other 7 groups,and all the differences were statistically significant（P〈0.05）.The D/S in 1 dgroup was higher than that of 0 dgroup,but lower than those of the other 6 groups,and all the differences were statically significant（P〈0.05）.There were no significant differences in the aspect of D/Samong 2-7 dgroups（P〈0.05）.（3） There was statistically significant difference in S1/S2 among8 groups after crying（χ~2=7.8,P〈0.001）.Multiple comparison results showed the following results.There were no significant differences in the aspects of S1/S2 among 0-2 dgroups（P〈0.05）.The S1/S2 in 0-2 groups all were significant lower than those of 3-7 dgroups,and all the difference were statistically significant（P〈0.05）.（4） There were statistically significant differences in the aspects of D/Sand CCCTS among 8 groups after crying（F=3.2,P=0.002;χ~2=8.9,P〈0.001）.Multiple comparison results showed the following results.The D/Sand CCCTS in 0 dgroup were lower than those of the other 7 groups,and all the differences were statistically significant（P〈0.05）.There were no significant differences in the aspects of D/Sand CCCTS among 1-7 dgroups（P〈0.05）.（5） The S1/S2 in 0 dgroup after crying was not significantly different from that in quiet time（P〈0.05）.But the S1/S2 in other 7 groups in quite state were all lower than those after crying,and all the differences were statistically significant（P〈0.001）.（6） The D/Sin 8 groups in quite state all were higher than those after crying,and all the differences were statistically significant（P〈0.001）.（7） The S1/S2 in quite state of all newborns in this study were negatively correlated with the D/S（rs=-0.1,P〈0.001）.（8） The multiple linear stepwise regression results showed that the dayage of newborns,gravidities of pregnant women and gender of newborns were the influencing factors of D/Sin quite state,and the newborns with older day-age,fewer gravidities of pregnant women,and boy had higher D/S.（9） The 95% reference ranges of CCR indexes in normal and full term early newborns were calculated based on PCGET results in this study.Conclusions A new evaluation system for CCR in normal and full term early newborns which is based on heart sound signal analysis has established.This evaluation system could provide the credentials for the heart health care of normal and full term early newborns in our country.