Assessment of Efficacy of Oral Rehydration Salts in Children With Neurally Mediated Syncope of Different Hemodynamic Patterns

Objective: To assess the efficacy of oral rehydration salts in children with neurally mediated syncope of different hemodynamic types.

Methods: Children with unexplained syncope or pre-syncope who visited or were hospitalized between March 2012 and February 2015 were enrolled in the study. Checked by the head-up tilt test, 105 children (aged 4-18 years, with a mean age of 11.96 ± 2.86 years) were diagnosed with neurally mediated syncope. Of them, 73 had vasovagal syncope (vasodepressor type in 46, mixed/cardioinhibitory types in 27), and 32 had postural orthostatic tachycardia syndrome. They were randomized into the oral rehydration salts plus health education group (n = 55) and the health education alone group (n = 50). All treated children were followed up. The follow-up time ranged from 6 to 25 (14.82 ± 6.13) months. Short-term effects were assessed according to the recurrence of clinical symptoms and reviews of head-up tilt test results 6 months after drug withdrawal. Long-term effects were compared between both groups of children with neurally mediated syncope.

Results: Short-term effect: No significant differences were found in subjective response rate and head-up tilt test negative results rate among different hemodynamic types ( P > .05). Long-term effect: Compared with the health education alone group, the cumulative response rate increased after treatment with oral rehydration salts ( P < .05). Among oral rehydration salts-treated children, the cumulative response rate was higher in those with vasodepressor vasovagal syncope than with mixed/cardioinhibitory vasovagal syncope ( P < .05).

Conclusion: Compared with children with mixed/cardioinhibitory vasovagal syncope, oral rehydration salt is more suitable for those with vasodepressor vasovagal syncope.