title: Shortened head-up tilting test guided by systolic pressure reductions in neurocardiogenic syncope.
abstract: BACKGROUND
  Asymptomatic reductions in arterial pressure have been reported to occur before the onset of tilt-induced syncope. We investigated the predictive value of these reductions for a positive tilt result.
  
  
  RESULTS
  In a first study, 238 consecutive healthy subjects with unexplained syncope underwent a passive tilt table test. Finger systolic arterial pressure (SAP) recordings made it possible to calculate how many of the beat-to-beat SAP values during the first 15 minutes of tilt were lower than the lowest value recorded at baseline. Neurocardiogenic syncope was diagnosed in 73 subjects; 28 fainted after 15 minutes of tilt and experienced more pressure reductions than did the subjects with a negative test (328+/-400 versus 119+/-284; P<0.01). More than 14 SAP reductions during the first 15 minutes of tilt allowed us to predict a positive test with 93% sensitivity, 58% specificity, and positive and negative predictive values of 28% and 98%, respectively. In a second prospective study (80 consecutive subjects), the online analysis of this criterion by visually inspecting a Finapres monitor showed 80% sensitivity, 85% specificity, and positive and negative predictive values of 57% and 94%.
  
  
  CONCLUSIONS
  In healthy subjects with unexplained syncope, the evaluation of SAP reductions during the first 15 minutes of tilt is a marker of systolic pressure instability preceding syncope and constitutes a simple and good predictor of tilt outcome that could be used to guide test duration.
authors.affiliation: Institute of Cardiology, and Innovative Technologies for Signal Detection and Processing Center, University of Bari, Bari, Italy. mariavittoria.pitzalis@cardio.uniba.it
authors.forename: Mariavittoria
authors.initials: M
authors.lastname: Pitzalis
authors.forename: Francesco
authors.initials: F
authors.lastname: Massari
authors.forename: Pietro
authors.initials: P
authors.lastname: Guida
authors.forename: Massimo
authors.initials: M
authors.lastname: Iacoviello
authors.forename: Filippo
authors.initials: F
authors.lastname: Mastropasqua
authors.forename: Brian
authors.initials: B
authors.lastname: Rizzon
authors.forename: Cinzia
authors.initials: C
authors.lastname: Forleo
authors.forename: Paolo
authors.initials: P
authors.lastname: Rizzon
mesh_terms: D000328:Adult; D001794:Blood Pressure; D005260:Female; D006257:Head; D006801:Humans; D008297:Male; D011187:Posture; D012680:Sensitivity and Specificity; D019462:Syncope, Vasovagal / Q000175:diagnosis*; D013599:Systole; D018667:Tilt-Table Test / Q000379:methods*; D013997:Time Factors