Clinical Autonomic Research

, Volume 17, Issue 2, pp 99–105 | Cite as

Increased hydration alone does not improve orthostatic tolerance in patients with neurocardiogenic syncope

  • Elisabeth Bellard
  • Jacques-Olivier Fortrat
  • Marc-Antoine Custaud
  • Jacques Victor
  • John Greenleaf
  • Georges Lefthériotis


In patients with neurocardiogenic syncope, the beneficial effects of increased daily fluid intake, without an accompanying high dose of salt, are unknown. Our aim was to (1) determine whether plasma volume was low in patients with recurrent neurocardiogenic syncope, and (2) determine how recommendation about increased daily fluid intake, without an accompanying high dose of sodium, effects plasma volume and if this potential therapy improves orthostatic tolerance. Eighty-six patients with neurocardiogenic syncope were recruited in a prospective randomized open study. After an initial head-up tilt test, patients were randomly assigned to either the hydration supplementation group (1500 ml of water + 1500 mg of NaCl/day) or the no treatment (control) group. After ten days a second head-up tilt test was performed. Plasma volume, osmolality, and total body water were measured at baseline, and heart rate, arterial blood pressure, and cardiac transthoracic impedance were monitored during tilting. Hydration treatment did not affect the number of positive tilt tests (52% initial day, 54% after treatment, NS). In both groups, the overall number of positive tilt tests decreased between the initial and final head-up tilt test. There was no association between low plasma volume and positive tilt test. Patients with the lowest plasma volume were equally distributed in both positive and negative tilt response groups. An increased daily intake of fluid, without an accompanying high dose of salt, had no measurable beneficial effect on tolerance to head-up tilting in patients with neurocardiogenic syncope. Moreover in this patient group there was no association between a low plasma volume and a reduced tolerance to orthostatic stress.


autonomic nervous system blood volume neurally mediated syncope Water water consumption tilt-table test 



The authors wish to thanks the nurses from the cardiology department and Dr Yves Gallois and Cédric Ménard for their technical help in plasma volume determination. This work was funded in part by Centre Evian pour l’Eau and supported by the Direction de la Recherche Clinique of the Centre Hospitalier of Angers. This study was supported by a grant from Centre Evian pour l’Eau. The sponsor of the study had no role in the study design, data collection, analysis, interpretation or writing of the report


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Copyright information

© Steinkopff Verlag Darmstadt 2007

Authors and Affiliations

  • Elisabeth Bellard
    • 1
  • Jacques-Olivier Fortrat
    • 1
  • Marc-Antoine Custaud
    • 1
  • Jacques Victor
    • 2
    • 3
  • John Greenleaf
    • 1
  • Georges Lefthériotis
    • 1
  1. 1.Laboratoire de Physiology, UMR CNRS 6214 Inserm 771, Faculté de Médecine d’Angers rue Haute de ReculéeAngersFrance
  2. 2.Service de CardiologieCentre Hospitalier Universitaire d’AngersAngers CedexFrance
  3. 3.Dept. of Human PerformanceSan Jose State UniversitySan JoseUSA

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