OBJECTIVES: Nitrate-stimulated head-up tilt testing (HUT) is currently recommended to confirm the diagnosis of vasovagal syncope in subjects with syncope of unknown origin. Given the few data currently available, the aim of this study was to assess correlations between nitrate-induced HUT outcomes and the clinical characteristics of patients. METHODS: Two hundred and thirty consecutive, otherwise healthy subjects with a history of recurrent unexplained syncope underwent HUT. After 10 min supine rest, they were tilted to 70 degrees , and the test was potentiated by the administration of 300 microg of nitroglycerin after 20 min. RESULTS: Out of 178 subjects who underwent nitroglycerin administration during HUT, 95 fainted. At univariate Cox regression analysis, a reduced probability of VVS occurrence after nitrates was associated with greater systolic blood pressure and body mass index values, to male gender and smoking. At multivariate Cox regression analysis, only male gender (HR = 0.61; P = 0.039) and smoking (HR = 0.18; P = 0.001) remained significantly associated with HUT outcomes during the pharmacological phase of the test. INTERPRETATION: Smokers and males are less likely to faint after nitrate administration during HUT than non-smokers and females. Further studies should clarify the possibility of improving the diagnostic power of HUT in these patients.
OBJECTIVES:Nitrate-stimulated head-up tilt testing (HUT) is currently recommended to confirm the diagnosis of vasovagal syncope in subjects with syncope of unknown origin. Given the few data currently available, the aim of this study was to assess correlations between nitrate-induced HUT outcomes and the clinical characteristics of patients. METHODS: Two hundred and thirty consecutive, otherwise healthy subjects with a history of recurrent unexplained syncope underwent HUT. After 10 min supine rest, they were tilted to 70 degrees , and the test was potentiated by the administration of 300 microg of nitroglycerin after 20 min. RESULTS: Out of 178 subjects who underwent nitroglycerin administration during HUT, 95 fainted. At univariate Cox regression analysis, a reduced probability of VVS occurrence after nitrates was associated with greater systolic blood pressure and body mass index values, to male gender and smoking. At multivariate Cox regression analysis, only male gender (HR = 0.61; P = 0.039) and smoking (HR = 0.18; P = 0.001) remained significantly associated with HUT outcomes during the pharmacological phase of the test. INTERPRETATION: Smokers and males are less likely to faint after nitrate administration during HUT than non-smokers and females. Further studies should clarify the possibility of improving the diagnostic power of HUT in these patients.
Authors: Michele Brignole; Paolo Alboni; David G Benditt; Lennart Bergfeldt; Jean-Jacques Blanc; Paul Erik Bloch Thomsen; J Gert van Dijk; Adam Fitzpatrick; Stefan Hohnloser; Jean Janousek; Wishwa Kapoor; Rose Anne Kenny; Piotr Kulakowski; Giulio Masotti; Angel Moya; Antonio Raviele; Richard Sutton; George Theodorakis; Andrea Ungar; Wouter Wieling Journal: Europace Date: 2004-11 Impact factor: 5.214
Authors: S R Barnett; R J Morin; D K Kiely; M Gagnon; G Azhar; E L Knight; J C Nelson; L A Lipsitz Journal: Hypertension Date: 1999-05 Impact factor: 10.190
Authors: Janneke Gisolf; Berend E Westerhof; Nynke van Dijk; Karel H Wesseling; Wouter Wieling; John M Karemaker Journal: J Am Coll Cardiol Date: 2004-08-04 Impact factor: 24.094