RESUMO
BACKGROUND: Clinical presentation varies in children with Orthostatic Intolerance. This study aimed to evaluate the epidemiological and clinical characteristics of pediatric patients with orthostatic intolerance (OI) and positive head-up tilt test (HUTT). METHODS: This study was a retrospective review of clinical data from outpatients over 18 months period. RESULTS: We included 112 patients with abnormal HUTT results. Females were 78 (70%). Mean age of presentation was 15.6 years (sd: 3.3). Fifteen percent were overweight, and 14% were obese. A headache and syncope were the most frequent presenting symptoms (46% and 29% respectively). Review of systems identified more patients with headaches (84%), Syncope (61%), presyncope (87%) and abdominal pain (29%). Except for fatigue being more prevalent during a review of systems among patients with severe OI (69%) compared to those with moderate OI (46%, p = 0.02), there was no statistically significant difference in the clinical presentation between investigator-defined moderate and severe OI. Comorbidities identified in this cohort were Chiari malformations (9%), idiopathic intracranial hypertension (9%), electroencephalographic abnormalities (8%) and patent foramen ovale (43%). CONCLUSIONS: Adolescents, mainly females had OI. Patients with OI and abnormal HUTT predominantly had a headache, syncope, and presyncope during the presentation. Eliciting review of systems and using tools such as clinical questionnaire identifies significant clinical presenting features and comorbidities.