title: Tilt testing results are influenced by tilt protocol.
abstract: OBJECTIVE
  It is unknown how the return to supine position influences duration of loss of consciousness (LOC) and cardioinhibition during tilt test.
  
  
  RESULTS
  Retrospective analysis of two datasets containing records of patients who underwent tilt testing for unexplained syncope in two centres was performed. Patients, totalling 1232, were included in the study: 262 in a Swedish centre and 970 patients in a Polish centre. In Sweden, tilt table with tilt-down time (TDT) of 18 s was used (Group II). In Poland, two different tilt tables were used, one of them with TDT of 10 s (Group I, n = 325), and the other with TDT of 47 s (Group III, n = 645). Cardioinhibitory reflex occurred most frequently in Group III, whereas number of pauses >3 s, frequency of very long asystole ≥30 s, and the total duration of pauses >3 s demonstrated a trend to increase from Group I to III. Duration of LOC in Groups II and III was significantly longer compared with Group I (32.0 and 33.7 s vs. 16.4 s). In the multivariate-adjusted regression model, cardioinhibitory reflex was predicted by tilt-table model (odds ratio per model with increasing TDT: 1.40; 95% confidence interval, 1.19-1.64; P < 0.0001), whereas LOC duration was longer with increasing TDT (P < 0.0001) and age (P < 0.0001).
  
  
  CONCLUSIONS
  Longer TDT during induced vasovagal syncope increases the prevalence of cardioinhibitory reflex and prolongs the duration of LOC. Tilt-down time does not affect asystolic pause duration but delay may lead to occurrence of multiple pauses, higher frequency of very long asystole, and longer total asystole duration.
authors.affiliation: Department of Emergency Medicine, Wroclaw Medical University, Wroclaw 51-618, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Zyśko
authors.affiliation: Department of Clinical Sciences, Lund University, Clinical Research Center, Skåne University Hospital, Malmö 205-02, Sweden Department of Cardiology, Skåne University Hospital, Inga Marie Nilssons Gata 46, Malmö 205-02, Sweden artur.fedorowski@med.lu.se.
authors.forename: Artur
authors.initials: A
authors.lastname: Fedorowski
authors.affiliation: Department of Clinical Sciences, Lund University, Clinical Research Center, Skåne University Hospital, Malmö 205-02, Sweden.
authors.forename: David
authors.initials: D
authors.lastname: Nilsson
authors.affiliation: Department of Minimally Invasive Surgery and Proctology, Wroclaw Medical University, Wroclaw 50-556, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Rudnicki
authors.affiliation: Department of Cardiology, Wroclaw Medical University, Wroclaw 50-556, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Gajek
authors.affiliation: Department of Clinical Sciences, Lund University, Clinical Research Center, Skåne University Hospital, Malmö 205-02, Sweden.
authors.forename: Olle
authors.initials: O
authors.lastname: Melander
authors.affiliation: National Heart and Lung Institute, Imperial College, St Mary's Hospital Campus, 59-61 North Wharf Road, London W2 1LA, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Sutton
mesh_terms: D000328:Adult; D000368:Aged; D016757:Death, Sudden, Cardiac / Q000209:etiology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011044:Poland; D012189:Retrospective Studies; D013548:Sweden; D019462:Syncope, Vasovagal / Q000175:diagnosis* / Q000503:physiopathology*; D018667:Tilt-Table Test / Q000379:methods*; D014474:Unconsciousness / Q000175:diagnosis* / Q000209:etiology; D055815:Young Adult
keywords: Cardiac arrest; Sudden cardiac death; Syncope; Tilt-table test; Unconsciousness; Vasovagal reflex