Differences of heart rate variability in cardioinhibitory type vasovagal syncope children with different body mass index / 中国小儿急救医学

ABSTRACT

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.