Objectives To explore the clinical application of deceleration capacity of rate (DC), acceleration capacity of rate (AC) and heart rate variability (HRV) in children with precardial distress of unknown origin. Methods A total of 56 children with precardial distress of unknown origin and 63 healthy children aged 6 to 17 years were examined by 24 h dynamic elec-trocardiogram, and the indexes of DC and HRV were compared between these two groups. Results DC value of children with precardial distress is less than that of the control group (P<0.05), AC value is greater than that of the control group (P<0.05), and heat rate (HR) is greater than that of the control group (P<0.05). No statistical differences were observed in the indexes of HRV between the two groups. The indexes of DC show a signiifcant positive correlation with HRV in children with precardial distress(r=0.27~0.40, P<0.05), while appear a negative relation with HR (r=-0.46, P=0.000). In contrast, the indexes of AC show a signiifcant negative correlation with HRV (r=-0.57~-0.34, P<0.05), and appears a positive relation with HR(r=0.61, P=0.000). HR value is higher in male children less than 12 years old with precardial distress than that of age-matched males in control group, and RMSSD is lower than the latter. DC value of male children more than 12 years with precardial distress is lower than that of age-matched males in control group, while AC value is higher than that of the latter;DC value is signiifcant lower in fe-male children more than 12 yeares with precardial distress than that of age-matched females in the control group (P<0.05). Con-clusions The activity of vagus nerve in children with precardial distress of unknown origin is decreased. DC value is signiifcantly lower than that of control group, and shows correlation with indexes of HRV. There is no signiifcant difference in DC and HRV value between male and female children with precardial distress. DC value is lower in children aged 12 or older with precardial distress than that of age-matched children in the control group, which indicates adolescents are vulnerable to autonomic nerve functional disorder.

Objective To explore the relationship between heart rate variability (HRV) and deceleration capacity (DC) in children with idiopathic ventricular premature contraction of different origins. Methods The clinical data from 155 children with idiopathic ventricular premature contraction were retrospectively analyzed. According to the age, the children were divided into young children group (

Objectives To explore the difference of heart rate deceleration capacity (DC), heart rate acceleration capacity (AC), and heart rate variability (HRV) among overweight children, obesity children, and metabolic syndrome (MS) children. The correlation between body mass index (BMI) and the indexes of DC, AC, and HRV was analyzed. Methods One hundred three overweight and obesity children over 10 years old were selected. The levels of DC, AC, and HRV were detected in these children. Results The level of DC (5.97±1.77 ms) in MS group was lower than that in non-MS group (7.93±1.56 ms); the level of AC (?6.78±1.56 ms) in MS group was higher than that in non-MS group (?8.17±1.61 ms2); the level of HF [335.2(157.03~659.33) ms2] in MS group was lower than that in non-MS group [497.5(345.6~767.1) ms2]; BMI (29.64±2.83 kg/m2) was higher than that in non-MS group (26.79±1.83 kg/m2) and the differences were statistically significant (P all < 0.05). The BMI in overweight and obesity children was negatively correlated with DC (r= ?0.241, P=0.014), and was positively correlated with AC (r=0.199, P=0.044). Conclusions The autonomic nervous function of MS patients is impaired, and the vagus nerve tension is decreased. The protective force on the heart was weaker in the higher degree of overweight, obesity and lower vagus nerve tension, and thus it was the more likely to cause cardiovascular disease.