Sensitivity and Specificity of the Tilt Table Test in Young Patients with Unexplained Syncope

The usefulness of the head‐up tilt testing (HUT) has heen previously addressed in diagnosing vasovagal neuroregulatory syncope in the teenage population. However, data concerning sensitivity and specificity is deficient due to the lack of control groups. We compared the response to HUT in young patients referred because of syncope or near syncope (n = 44, mean age 16 ± 3 years SD) to healthy young volunteers with a normal physical examination and no previous history of syncope (n = 18, mean age 16 ± 2 years) and io determine the sensitivity and specificity of HUT. The graded tilt protocol was performed at 15°, 30°, and 45° (each for 2 min), and then 60° for 20 minutes. Cuff blood pressure was measured every minute and lead IIECG was continuously monitored. Results; 25 of the 44 patients (57%) developed a vasovagaJ response or became symptomatic after 13.8 ± 5.7 minutes of HUT. Three of the 18 volunteers (17%) had a vasovagal response and became symptomatic after 9 ± 3 minutes of HUT. There was no statistical difference among the four groups (with and without tilt induced vasovagal response) in terms of age and baseline hemodynamic data. The sensitivity of 20 minutes HUT was 57% and its specificity was 83%. The presyncopal hemodynamic response in patients with history of syncope that was characterized by a significant decrease in systolic blood pressure and lack of increase of diastolic blood pressure as compared with baseline and with other groups. Gonclusions: 20 minutes at 60° HUT has a high specificity for the diagnosis of vasovagal syncope. Its limited sensitivity is counterbalanced by the advantage of limiting the incidence of false‐positive results in patients without the vasovagal syndrome.