[Relationship between blood routine test parameters and syncopal recurrence of vasovagal syncope in children]

Objective: To explore the relationship between venous blood routine test parameters and syncopal recurrence of children with vasovagal syncope (VVS). Method: Sixty-three children (male 32, female 31) diagnosed as VVS in Department of Pediatrics, Peking University First Hospital from November 2010 to October 2015 were included in a case observational study.Their mean age was (11.2±2.7) years and basic treatment such as predisposing causes avoiding, standing training, autonomic nervous function exercise and oral rehydration salts were advised to them.The clinical data were obtained by out-patient visit and over telephone from December 2015 to January 2016, with a median follow-up period of 10 (4, 26) months. The effects of baseline venous blood routine test parameters, gender, age, and body mass index (BMI) on syncopal recurrence were studied via univariate and multivariate Cox regression analysis.Kaplan-Meier curve was used to evaluate the long-term prognosis. Result: Among the 63 VVS children in this study, 31 cases were diagnosed as VVS vasodepressor type, 4 cases as VVS cardioinhibitory type and 28 cases as VVS mixed type, 16 cases (25%) had experienced recurrence of syncope while 47 cases (75%) had not.The result of univariate analysis of Cox regression showed that baseline platelet count (PLT) (HR=1.012, 95%CI: 1.003-1.022) had a marked impact on the survival rate.And the result of multivariate analysis of Cox regression showed that baseline hemoglobin concentration (HGB) (HR=1.055, 95%CI: 1.007-1.105), mean corpuscular hemoglobin (MCH) (HR=0.612, 95%CI: 0.423-0.884) and PLT(HR=1.015, 95%CI: 1.006-1.024) had significant effects on survival rate of VVS children.In this study, the one-year, two-year, and three-year survival rate were 83% (52/63), 79% (50/63) and 75% (47/63), respectively. Conclusion: The baseline venous blood routine test parameters HGB, MCH and PLT might be the influencing factors of the syncopal recurrence of VVS children.