title: Diagnosis of neurally mediated syncope at initial evaluation and with tilt table testing compared with that revealed by prolonged ECG monitoring. An analysis from the Third International Study on Syncope of Uncertain Etiology (ISSUE-3).
abstract: OBJECTIVE
  According to the guidelines of the European Society of Cardiology, a presumed diagnosis of neurally mediated syncope (NMS) can be made when patients have a consistent history and competing diagnoses are excluded. In the present study, we compared the initial diagnosis of NMS by means of implantable loop recorder (ILR) documentation.
  
  
  METHODS
  In this prospective multicentre observational study which involved 51 hospitals in nine countries in Europe and Canada, 504 NMS patients ≥40 years, who had suffered ≥3 syncopal episodes in the previous 2 years received an ILR and were followed up for a mean of 15±11 months.
  
  
  RESULTS
  ILR recorded a spontaneous syncope in 187 cases, with an estimated diagnostic yield of 47% at 3 years. ILR findings were consistent with the initial diagnosis of presumed NMS in 162 (87%) patients whereas did not confirm NMS in another 25 (13%), who had an intrinsic cardiac arrhythmic cause (atrial tachyarrhythmias (#6), long pause on termination of tachyarrhythmia (#8), persistent bradycardia (#3), ventricular tachycardia (#4)) or a non-arrhythmic loss of consciousness (non-syncopal (#3), orthostatic hypotension (#1)). No clinical baseline feature was able to predict an intrinsic cardiac cause with the exception of more frequent non-syncopal atrial tachyarrhythmias on clinical history, which were present in 38% of cardiac versus 5% of NMS patients (p=0.001). Tilt table testing (TT) was positive in 76/136 (56%) presumed NMS and in 9/21 (43%) non-NMS patients (p=0.35); an asystolic response was present in 28/136 (21%) NMS and in 0/21 (0%) non-NMS patients (p=0.03).
  
  
  CONCLUSIONS
  ILR findings showed results other than NMS in a small, although non-negligible, number of patients older than 40 years. TT was unable to discriminate between presumed NMS and non-NMS with the exception of an asystolic response which was highly specific.
authors.affiliation: Departments of Cardiology, Ospedale Careggi, , Firenze, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ungar
authors.forename: Paolo
authors.initials: P
authors.lastname: Sgobino
authors.forename: Vitantonio
authors.initials: V
authors.lastname: Russo
authors.forename: Elena
authors.initials: E
authors.lastname: Vitale
authors.forename: Richard
authors.initials: R
authors.lastname: Sutton
authors.forename: Donato
authors.initials: D
authors.lastname: Melissano
authors.forename: Xulio
authors.initials: X
authors.lastname: Beiras
authors.forename: Nicola
authors.initials: N
authors.lastname: Bottoni
authors.forename: Hans H
authors.initials: HH
authors.lastname: Ebert
authors.forename: Michele
authors.initials: M
authors.lastname: Gulizia
authors.forename: Marcella
authors.initials: M
authors.lastname: Jorfida
authors.forename: Angel
authors.initials: A
authors.lastname: Moya
authors.forename: Dietrich
authors.initials: D
authors.lastname: Andresen
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Grovale
authors.forename: Michele
authors.initials: M
authors.lastname: Brignole
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D003937:Diagnosis, Differential; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013575:Syncope / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D018667:Tilt-Table Test
keywords: AUTONOMIC NERVOUS SYSTEM