Clinical Risk Factors For Syncope In Children Of Orthostatic Intolerance

Objective: To study the relationship between clinical features which including sex, age, body mass index, inducement, accompanied symptoms and so on and syncope in children with orthostatic intolerance, in order to investigate the risk factors for syncope in children with orthostatic intolerance(OI).Methods: 117 patients of orthostatic intolerance with prodromal symptoms which including recurrent episodes of dizziness, chest congestion, sighs and so on or unexplained but can spontaneous restoring syncope admitted in the department of pediatrics cardiovascular of The Second Hospital of Lanzhou University from April 2014 to March 2015 were enrolled in the study. All patients had positive responses in head-up tilt table test. And their clinical features were carefully inquired and collected and recorded including sex, age, height, weight, inducement, accompanied symptoms, the number of syncope, the history of motion sickness, family history, performance of head-up tilt table test, outcomes of head-up tilt table test, syncope-related injuries. The children were divided into syncope group(n=75 cases) and non-syncope group(n=42 cases) based on the existence of syncope; and then according to frequency of syncope,the patients of syncope group were divided into two groups,occasional syncope group(n=27 cases)and recurrent syncope group(n=48 cases). All risk factors were compared between syncope group and non-syncope group, occasional syncope group and recurrent syncope group. All data were statistical analysis by SPSS 19.0 software.Results: ① Among the 117 children, 56 cases were male and 61 cases were female and the age ranged from 6 to 18 years with the average age of(10.52±2.82) years. Among these Children, 75(64.10%) cases were occasional syncope group, 48(41.03%)cases were recurrent syncope group. ② The differences in prevalence of inducement of prolonged standing, prevalence of accompanied symptoms of blurred vision/ blacking out, cold sweating and pallor, prevalence of the history of motion sickness were statistically significant between two groups(P<0.05).Compared with non-syncope group, the patients of syncope group have lower body mass index, the difference was statistically significant(P<0.05). No significant difference were found in age distribution, gender, prevalence of family history, prevalence of performances of head-up tilt table test, prevalence of outcomes of head-up tilt table test, prevalence of other inducements and other accompanied symptoms(P >0.05). ③ Of all studied risk factors,the BMI and the prevalence of history of motion sickness were significantly different between occasional syncope group and recurrent syncope group(P<0.05).There were no significant differences in age distribution, gender, and the prevalence of inducements, accompanied symptoms, performances of head-up tilt table test, outcomes of head-up tilt table test, family history, syncope-related injuries between two groups(P >0.05).Conclusions: Children with orthostatic intolerance who has low body mass index, inducement of prolonged standing, accompanied symptoms of blurred vision/ blacking out, cold sweating and pallor, the history of motion sickness, are prone to syncope. Especially when the patients with low body mass index or(and) have the history of motion sickness, we should pay more attention for preventing syncope events and alert the recurrent syncope events.