Around 15% of children and adolescents experience at least one episode of syncope until adulthood. Excluding cardiac disease, the majority of syncopes are of reflex origin and benign in nature. In this situation, a tilt test is conducted to reproduce symptoms and to evaluate cardiovascular adaptations to orthostatism, but its mechanisms are not yet well defined. Here, we investigated haemodynamics and autonomic activity during tilt in young patients. Patients (n=113) with unexplained syncope were enrolled. Tilt followed a standard protocol without provocative agents. A positive response (fainters) was defined as a sudden development of syncope or presyncope associated with hypotension, bradycardia, or both. Haemodynamic parameters, autonomic activity, and baroreflex sensibility were evaluated. Data were analysed on baseline; immediately after tilting; on tilt adaptation; before fainting or before tilt-down for non-fainters; and on tilt-down. A total of 45 patients experienced syncope after a mean time of 18 minutes. During tilting up, fainters showed lower blood pressure and peripheral resistance values, which decreased progressively with time together with baroreflex sensibility. Sympathetic tone increased massively along time till syncope. No changes in cardiac output and heart rate were observed. Results show a strong effort of the autonomic nervous system to adapt to orthostatic stress through different magnitudes of sympathetic output, which was maximal before syncope without apparent modifications of parasympathetic tone. These changes suggest an imbalance between both branches of the autonomic nervous system, not enabling a time-progressive adaptation and leading the subject to faint.

The objectives of this study were to assess the prevalence of fear of falling (FOF) among patients over age 60 with dizziness, falls, or syncope; and to analyze risk factors associated with FOF, including data from the tilt table test. This study included 200 older patients referred to a geriatric outpatient clinic specializing in dizziness, falls, and syncope. The primary outcome measure was the proportion of patients who experienced FOF (yes vs. no) and whether FOF restricted leaving home alone or performing activities of daily living. FOF occurred in 50 per cent of patients in this population. Among these, 44 per cent gave up going out alone and 10 per cent stopped doing basic activities of daily living. Beyond age 75, FOF was associated with recurrent dizziness, depression, and symptoms on standing, but not prior falls.

Syncope has never been described as the presenting symptom of divided left atrium (cor triatriatum sinistrum). We have now encountered this mode of presentation in an otherwise asymptomatic patient. An upright tilt test elicited syncope prior to surgical correction, but failed to induce any symptom, even subsequent to infusion of isoproterenol, after surgery.