Head-up tilt table testing with sublingual isosorbide dinitrate in the diagnosis of vasovagal syncope in children.

OBJECTIVE To evaluate the effect of sublingual administration of ISDN on the results of the head-up tilt table test (HUTT) in children and adolescents with vasovagal syncope. MATERIALS AND METHODS The study group consisted of 30 children, each with at least one incidence of vasovagal syncope, and the control group had 15 healthy children. The patients were tilted upright at an angle of 60° for 15 minutes. If the test was negative, sublingual ISDN was administered and the test was continued for an additional 15 minutes. RESULTS The sensitivity and specificity of the basal test were 30% and 100%, respectively. Although the specificity decreased somewhat (93.3%) after sublingual ISDN, the sensitivity significantly increased to 96.7%. No severe complications were observed after sublingual ISDN administration. CONCLUSION Our results suggested that sublingual ISDN is a useful, effective and safe agent for pharmacologic stimulation and measurement of the HUTT in children. It increased the sensitivity of the test with a slight decrease in specificity.