Reproducibility of the head-up tilt test results in children with vasovagal syncope

Background: This prospective study aims to investigate the reproducibility of HUTT results in children with typical history of vasovagal syncope. Methods: Between October 1996 and October 1999, 58 children with a history of typical vasovagal syncope attacks were evaluated with head up tilt test (HUTT). The table was tilted to 60° and the patients were monitored for heart rate and blood pressure changes during 45 min. No provocative agents were used. The test was repeated a week later at a similar setting. Results: Of 58 patients, 39 had positive and 19 had negative response during the initial test. During the second test, the positive response was reproduced in 29 cases (50%), and the negative response was reproduced in 16 cases (28%). Ten patients (17%) with an initial positive test had a negative second test. A negative test became positive only in three patients (5%). There were 12 vasodepressor, four cardioinhibitor and 23 mixed responses among the initial tests. Only in four patients did the type of the response change from vasodepressor to a mixed type during the second test. The reproducibility of a positive tilt test was 74.4% (29/39), the negative tilt test was 84.2% (16/19), and the overall reproducibility of the HUTT was 77.6% (45/58). Conclusions: Unprovoked HUTT in children is reproducible when repeated on different days and similar settings and the results are comparable to the ones with adult patients.