title: Ambulatory postural blood pressure changes and history allow a better selection of patients that should undergo a head-up tilt test.
abstract: BACKGROUND
  Syncope is a common symptom and in most cases it is of a neurally mediated origin. Such patients have to be studied with a careful history and a physical exploration that should include simple maneuvers such as blood pressure (BP) recordings in decubitus and standing position. These tools can suggest diagnosis in a good percentage of patients without the need for expensive or invasive testing.
  
  
  METHODS
  We carried out a prospective observational study measuring BP and heart rate (HR) with the patients in decubitus and just as they stood up. The patients were sent for a tilt table test in different specialized centers. The BP changes were compared to the results of the tilt test.
  
  
  RESULTS
  We included 215 patients, 36.1 ± 18.8 years old, 118 (54.9%) feminine, of which 143 (66.5%) had a positive tilt test. Patients with a positive test showed a rise in systolic BP (SBP) (121.7 ± 19.1 vs. 124.2 ± 20, p < 0.005) and in diastolic BP (DBP) (75 ± 11 vs. 78 ± 11.3, p < 0.005) when compared to people with a negative one. On the other hand, percentage BP changes were significantly different (SBP 2.24% vs. 0.48%, p = 0.02; DBP 4.1% vs. 1.2%, p = 0.009). Patients with a positive test had also a lower HR on standing up (72.1 ± ± 11.1 vs. 78.3 ± 17.2, p = 0.01).
  
  
  CONCLUSIONS
  Patients with neurally mediated syncope showed an elevation of SBP and DBP when standing up actively, unlike subjects with a negative tilt test.
authors.affiliation: Cardiology, Electrophysiology Head, Medicine Department, Hospital Medica TEC 100, Mexico. easensiol@gmail.com.
authors.forename: Enrique
authors.initials: E
authors.lastname: Asensio
authors.forename: Melisa
authors.initials: M
authors.lastname: Lecuna
authors.forename: Eliodoro
authors.initials: E
authors.lastname: Castro
authors.forename: Jose Benito
authors.initials: JB
authors.lastname: Alvarez
authors.forename: Susano
authors.initials: S
authors.lastname: Lara
authors.forename: Humberto
authors.initials: H
authors.lastname: Castro
authors.forename: Leonor
authors.initials: L
authors.lastname: Mendoza
authors.forename: Nidia
authors.initials: N
authors.lastname: Cordero
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D018579:Patient Selection; D011187:Posture; D011237:Predictive Value of Tests; D011446:Prospective Studies; D019462:Syncope, Vasovagal / Q000175:diagnosis* / Q000503:physiopathology; D018667:Tilt-Table Test; D013997:Time Factors; D055815:Young Adult