Randomized Assessment of Syncope Trial

To the Editor:The recent article published in Circulation by Krahn et al1 underlines the usefulness of implantable loop recorders in the investigation of unexplained syncope.Patients with unexplained syncope were randomized to a “conventional” investigation strategy or to a “prolonged monitoring” strategy with an implantable loop recorder, with the latter strategy yielding a higher diagnostic rate. The conventional investigation strategy did not include, however, carotid sinus massage (CSM) in supine or erect positions as part of the protocol.CSM is a safe, simple procedure2 that takes little time if added to a head-up tilt protocol such as that used by the authors and yields a diagnosis …