title: Investigation of various types of neurocardiogenic response to head-up tilting by extended hemodynamic and neurohumoral monitoring.
abstract: BACKGROUND
  The pathophysiology of neurocardiogenic syncope is heterogeneous. This study aim was to analyze whether extended monitoring during tilt-table testing provided additional information on the hemodynamic and vegetative state prior to neurocardiogenic syncope.
  
  
  METHODS
  This retrospective analysis is based on data of head-up tilt-table testing of 40 unselected consecutive patients with a history of unexplained syncope. For optimized characterization of the type of syncope, monitoring included electrocardiogram (ECG), blood pressure measurements and cardiac output, peripheral vascular resistance and contractility index measurements by impedance cardiography, as well as epinephrine and norepinephrine plasma levels in supine position and every 5 min during tilting.
  
  
  RESULTS
  Seven of 40 patients were unsuitable for analysis because of incomplete data sets. Tilt-table was positive in 26 patients, negative in 7. Groups did not differ in hemodynamic and catecholaminergic parameters at baseline. Responses to tilting were VASIS 1 (mix of cardioinhibitory and vasodepressor) in 5 patients, VASIS 2B (cardioinhibitory with asystole >3 sec) in 3, VASIS 3 (vasodepressor) in 16, orthostatic dysregulation in 2. In VASIS 1, the catecholamine measurement 4 min before syncope showed a proportionally larger increase of the epinephrine level than of norepinephrine. This disproportion was not observed in VASIS 2B and 3. In VASIS 2B, strong vasoconstriction and negative inotropy were evident in the presyncopal period. In VASIS 3, vascular resistance decreased continuously before syncope, while contractility index increased inadequately. Presyncopal epinephrine surge or norepinephrine loss was not observed in this group, suspecting other vasodilating factors.
  
  
  CONCLUSIONS
  Extended monitoring by impedance cardiography and plasma catecholamine measurements during tilt-table testing gave further insight into different hemodynamic and neurohumoral presyncopal patterns among the various types of neurocardiogenic syncope and may thereby help to develop individualized therapeutic concepts.
authors.affiliation: Staedtisches Klinikum Muenchen GmbH, Klinikum Bogenhausen, Department of Cardiology and Intensive Care Unit, Munich, Germany. lorenz.nowak@web.de
authors.forename: Lorenz
authors.initials: L
authors.lastname: Nowak
authors.forename: Franz G
authors.initials: FG
authors.lastname: Nowak
authors.forename: Sabine
authors.initials: S
authors.lastname: Janko
authors.forename: Uwe
authors.initials: U
authors.lastname: Dorwarth
authors.forename: Ellen
authors.initials: E
authors.lastname: Hoffmann
authors.forename: Florian
authors.initials: F
authors.lastname: Botzenhardt
mesh_terms: D001795:Blood Pressure Determination; D002302:Cardiac Output; D002307:Cardiography, Impedance; D002406:Catheterization, Peripheral; D004562:Electrocardiography; D004837:Epinephrine / Q000097:blood; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D009638:Norepinephrine / Q000097:blood; D012189:Retrospective Studies; D019462:Syncope, Vasovagal / Q000503:physiopathology*; D018667:Tilt-Table Test; D014655:Vascular Resistance
chemical_list: D009638:Norepinephrine; D004837:Epinephrine