title: Early hemodynamic response to the tilt test in patients with syncope.
abstract: BACKGROUND
  Our aim was to evaluate the differences in the early hemodynamic response to the tilt test (HUTT) in patients with and without syncope using impedance cardiography (ICG).
  
  
  METHODS
  One hundred twenty-six patients (72 female/48 male; 37 ±17 years) were divided into a group with syncope (HUTT(+), n = 45 patients) and a group without syncope (HUTT(-), n = 81 patients). ECG and ICG signals were continuously recorded during the whole examination, allowing the calculation of heart rate (HR), stroke volume (SV), and cardiac output (CO) for every beat. The hemodynamic parameters (averaged over 1 min) were analyzed at the following points of the HUTT: the last minute of resting, the period immediately after the tilt (0 min), 1 min and 5 min after the maneuver. The absolute changes of HR, SV and CO were calculated for 0, 1, and 5 min after the maneuver in relation to the values at rest (ΔHR, ΔSV, ΔCO). Also, the percentage changes were calculated (HRi, SVi, COi).
  
  
  RESULTS
  There were no differences between the groups in absolute and percentage changes of hemodynamic parameters immediately after and 1 min after tilting. Significant differences between the HUTT(+) and HUTT(-) groups were observed in the 5(th) min of tilting: for ΔSV (-27.2 ±21.2 ml vs. -9.7 ±27.2 ml; p = 0.03), ΔCO (-1.78 ±1.62 l/min vs. -0.34 ±2.48 l/min; p = 0.032), COi (-30 ±28% vs. -0.2 ±58%; p = 0.034).
  
  
  CONCLUSIONS
  In the 5(th) min the decrease of hemodynamic parameters (ΔSV, ΔCO, COi) was significantly more pronounced in HUTT(+) patients in comparison to the HUTT(-) group.
authors.affiliation: Chair and Department of Cardiology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Edward
authors.initials: E
authors.lastname: Koźluk
authors.affiliation: Department of Applied Physiology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland ; Institute of Metrology and Biomedical Engineering, Department of Mechatronics, Warsaw University of Technology, Warsaw, Poland.
authors.forename: Gerard
authors.initials: G
authors.lastname: Cybulski
authors.affiliation: Chair and Department of Cardiology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Piątkowska
authors.affiliation: Chair and Department of Cardiology, Medical University of Warsaw, Warsaw, Poland ; Department and Clinic of Cardiac Rehabilitation and Noninvasive Electrocardiology, The Cardinal Stefan Wyszynski Institute of Cardiology, Warsaw, Poland.
authors.forename: Inga
authors.initials: I
authors.lastname: Zastawna
authors.affiliation: Department of Applied Physiology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland ; Chair and Department of Experimental and Clinical Physiology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Wiktor
authors.initials: W
authors.lastname: Niewiadomski
authors.affiliation: Department of Applied Physiology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Strasz
authors.affiliation: Department of Applied Physiology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Gąsiorowska
authors.affiliation: Department of Cardiology and Electrotherapy, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Kempa
authors.affiliation: Department of Clinical Subjects, Institute of Health Sciences, Pomeranian University of Slupsk, Slupsk, Poland.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Kozłowski
authors.affiliation: Chair and Department of Cardiology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Opolski
keywords: head-up tilt test; hemodynamic parameters; impedance cardiography; vasovagal syncope