不同体重指数血管迷走性晕厥心脏抑制型儿童心率变异性的差异

Differences of heart rate variability in cardioinhibitory type vasovagal syncope children with different body mass index

目的探讨不同体重指数(BMI)血管迷走性晕厥心脏抑制型(VVS-CI)儿童心率变异性(HRV)的差异。方法回顾性分析2012年1月至2019年12月因晕厥或晕厥先兆在中南大学湘雅二医院儿童晕厥专科门诊诊断为VVS-CI的34例儿童的临床资料。根据身高、体重计算体重指数(BMI),分为偏瘦组(BMI≤18.4 kg/m^(2),n=19)和正常组(BMI 18.5-23.9 kg/m^(2),n=15)。对24 h动态心电图HRV进行分析。HRV分析采用线性分析法,时域指标SDNN、SDANN、rMSSD和pNN50,频域指标总功率(TP)、超低频功率(ULF)、极低频功率(VLF)、低频功率(LF)、高频功率(HF)和LF/HF。结果偏瘦组与正常组比较SDNN、SDANN和rMSSD差异无统计学意义(P>0.05),pNN50升高(P<0.05)。两组间TP、ULF、LF、HF和LF/HF差异无统计学意义(P>0.05),偏瘦组较正常组VLF降低(P<0.05)。偏瘦组、正常组不同性别之间时域指标、频域指标差异无统计学意义(P>0.05)。偏瘦组<12岁较≥12岁SDNN、SDANN、LF升高(P<0.05),rMSSD、pNN50、TP、ULF、VLF、HF和LF/HF差异无统计学意义(P>0.05)。正常组<12岁较≥12岁ULF升高、LF降低(P<0.05),SDNN、SDANN、rMSSD、pNN50、TP、VLF、HF和LF/HF差异无统计学意义(P>0.05)。结论低BMI与正常BMI的VVS-CI儿童自主神经调节功能不同,引起HRV存在差异。相同BMI<12岁与≥12岁儿童之间HRV也存在差异。

Objective To investigate the difference of heart rate variability in cardioinhibitory type vasovagal syncope(VVS-CI)children with different body mass index(BMI).Methods Clinical data of thirty-four children with syncope or pre-syncope were retrospectively analyzed,who visited specialist clinic for syncope and diagnosed as VVS-CI at the Second Xiangya Hospital of Central South University from January 2012 to December 2019.BMI was calculated based on height and weight,and divided into lean group(BMI≤18.4 kg/m^(2),n=19)and normal group(BMI 18.5-23.9 kg/m^(2),n=15).Heart rate variability(HRV)of 24 h dynamic electrocardiogram was analyzed using linear analysis method.Time domain index included SDNN,SDANN,rMSSD and pNN50.Frequency domain index included total power(TP),ultra low frequency power(ULF),very low frequency power(VLF),low frequency power(LF),high frequency power(HF)and LF/HF.Results There was no significant difference in SDNN,SDANN and rMSSD between lean and normal group(P>0.05),but pNN50 increased in lean group(P<0.05).No significant differences were found in TP,ULF,LF,HF and LF/HF between two groups(P>0.05),while VLF was lower in lean group than that in normal group(P<0.05).There was no statistical difference in time domain index and frequency domain index between different gender between lean and normal group(P>0.05).SDNN,SDANN and LF were higher in<12 years old than those in≥12 years old in lean group(P<0.05).There was no statistical difference in rMSSD,pNN50,TP,ULF,VLF,HF and LF/HF(P>0.05).ULF increased and LF decreased in<12 years old compared to≥12 years old in normal group(P<0.05).No statistical differences were found in SDNN,SDANN,rMSSD,pNN50,TP,VLF,HF and LF/HF(P>0.05).Conclusion The autonomic nervous regulation function of VVS-CI children with low BMI and normal BMI is different,resulting in HRV difference.There were also differences in HRV between<12 years old and≥12 years old with the same BMI.