title: Provocation of neurocardiogenic syncope during head-up tilt testing in children: comparison between isoproterenol and nitroglycerin.
abstract: OBJECTIVE
  Although nitroglycerin- and isoproterenol-augmented tilt tests are of equal value in the diagnosis of neurocardiogenic syncope in adults, no data exist in children. We compared the sensitivity and specificity of the 2 tests in a pediatric population.
  
  
  METHODS
  We studied 85 patients (33 boys; mean age: 11.6 +/- 2.9 years). Of them, 56 had a diagnostic history of neurocardiogenic syncope, whereas 29 served as controls. After a negative passive phase, they were randomly assigned to either intravenous isoproterenol or sublingual nitroglycerin, and tilt was continued for 20 minutes.
  
  
  RESULTS
  Sensitivity was 0.78 for the isoproterenol test and 0.79 for the nitroglycerin test, but specificity was significantly higher for isoproterenol test compared with nitroglycerin test. In patients with a positive test, the duration of the recovery period was significantly longer after nitroglycerin (8.4 +/- 2.7 minutes) than after isoproterenol (5.1 +/- 1.6 minutes).
  
  
  CONCLUSIONS
  Nitroglycerin- and isoproterenol-augmented tilt tests are associated with equal sensitivity in the diagnosis of neurocardiogenic syncope in children and adolescents. However, nitroglycerin results in more false-positive tests and produces more prolonged vasovagal symptoms. Our data do not support the routine use of nitroglycerin in the evaluation of syncope in this age group.
authors.affiliation: Child Health Department, Pediatric Cardiology Division, University of Ioannina, 45110 Ioannina, Greece. anvlahos@uoi.gr
authors.forename: Antonios P
authors.initials: AP
authors.lastname: Vlahos
authors.forename: Meropi
authors.initials: M
authors.lastname: Tzoufi
authors.forename: Christos S
authors.initials: CS
authors.lastname: Katsouras
authors.forename: Theodora
authors.initials: T
authors.lastname: Barka
authors.forename: Irene
authors.initials: I
authors.lastname: Sionti
authors.forename: Lampros K
authors.initials: LK
authors.lastname: Michalis
authors.forename: Antigoni
authors.initials: A
authors.lastname: Siamopoulou
authors.forename: Theofilos M
authors.initials: TM
authors.lastname: Kolettis
mesh_terms: D000286:Administration, Sublingual; D002648:Child; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007545:Isoproterenol / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D005996:Nitroglycerin / Q000008:administration & dosage / Q000009:adverse effects; D012680:Sensitivity and Specificity; D019462:Syncope, Vasovagal / Q000175:diagnosis* / Q000209:etiology; D018667:Tilt-Table Test
chemical_list: D005996:Nitroglycerin; D007545:Isoproterenol