title: Reproducibility of nitrate-stimulated tilt testing in patients with suspected vasovagal syncope and a healthy control group.
abstract: OBJECTIVE
  Nitrate-stimulated tilt testing may be used to diagnose vasovagal syncope or to guide therapy. To date, the reproducibility of the test in patients with clinically suspected vasovagal syncope and healthy controls is undetermined. A high reproducibility is a prerequisite for correct interpretation of the test result. This study investigates the reproducibility of a nitrate-stimulated tilt test in patients with clinically suspected vasovagal syncope and a healthy control group.
  
  
  RESULTS
  We studied 43 patients (24 women, 19 men) with a typical history of vasovagal syncope and 18 healthy controls (3 women, 15 men). We used a combined tilt protocol with a 30-minute passive and 15-minute nitrate-stimulated phase. The second tilt test was performed 16 +/- 12 days after the first. In both patients and controls, overall positive tilt responses were reproduced in the second test in 100%. In contrast to this, the reproducibility of an overall negative test was 50% in patients but 93% in controls. Overall hemodynamic responses to tilt were reproducible in 80%.
  
  
  CONCLUSIONS
  Nitrate-stimulated tilt testing in both patients with suspected vasovagal syncope and controls has an excellent reproducibility of positive results but a moderate reproducibility of negative results. Importantly, these results are still valid at a repeat interval of 2 weeks and longer. These data suggest that in patients with suspected vasovagal syncope, a nitrate-stimulated tilt test may provide a suitable tool to evaluate the efficacy of a therapeutic approach.
authors.affiliation: Department of Cardiology, Atrium Medisch Centrum, Heerlen, The Netherlands. AAS02@atriummc.nl
authors.forename: Arnaud J J
authors.initials: AJ
authors.lastname: Aerts
authors.forename: Paul
authors.initials: P
authors.lastname: Dendale
authors.forename: Pierre
authors.initials: P
authors.lastname: Block
authors.forename: Willem R M
authors.initials: WR
authors.lastname: Dassen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D004562:Electrocardiography; D005260:Female; D006323:Heart Arrest / Q000209:etiology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007545:Isoproterenol; D007548:Isosorbide Dinitrate / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin; D018579:Patient Selection; D011187:Posture; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019462:Syncope, Vasovagal / Q000175:diagnosis*; D018667:Tilt-Table Test / Q000379:methods*
chemical_list: D005996:Nitroglycerin; D007548:Isosorbide Dinitrate; D007545:Isoproterenol