The value of TT for diagnosing vasovagal syncope in children and the clinical efficacy of drinking-water

Objective To study the value of Tilt-table test (TT) for diagnosing vasovagal syncope and the clinical efficacy of drinking- water.Methods In prospective study,74 patients with unexplained syncope and 54 healthy children received the TT to 80° for 30 minutes.Positive-to-negative test was performed in the positive group,who eventually were treated with drinking-water,and were followed up.Results The classic TT was positive in 55.4% of patients with unexplained syncope,but none in control subjects.Three patterns of positive response to TT were observed :vasodepressor pattern in 21/41,cardioinhibitory pattern in7/41,and mixed pattern in 13/41.Among the positive group,28/41turned negative after drinking water.Follow-up was available to 38 patients,the total effective rate being 86.8%.Conclusion TT has higher sensibility and specificity to the diagnosis of vasovagal syncope.Positive-to-negative test provides rational and experimental evidence.Drinking-water is a simple and effective measure for the prevention of vasovagal syncope.