The Iliac Arterio-venous Fistula for Treatment of Neurally Mediated Syncope Study

Inclusion Criteria: * Absence of transient loss of consciousness associated with reflex bradycardia or hypotension on tilt testing at 3 months following randomised intervention Exclusion Criteria: * Time to first episode of syncope after randomised intervention * Number of syncopal episodes in the first 3 months after randomised intervention. * Tilt table response at 6 months following randomised intervention i.e. 3 months after unblinding * Number of syncopal episodes at 6 months after intervention i.e. 3 months after unblinding