Increased hydration alone does not improve orthostatic tolerance in patients with neurocardiogenic syncope
- 25 April 2007
- journal article
- research article
- Published by Springer Science and Business Media LLC in Clinical Autonomic Research
- Vol. 17 (2), 99-105
- https://doi.org/10.1007/s10286-007-0409-0
Abstract
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.Keywords
This publication has 25 references indexed in Scilit:
- Syncope: a clinically guided diagnostic algorithmClinical Autonomic Research, 2004
- Pharmacological treatment of reflex syncopeClinical Autonomic Research, 2004
- Nonpharmacological treatment of reflex syncopeClinical Autonomic Research, 2004
- Pathophysiology of syncopeClinical Autonomic Research, 2004
- Water drinking as a potential treatment for idiopathic exercise-related syncopeClinical Autonomic Research, 2003
- Effects of dietary salt on orthostatic tolerance, blood pressure and baroreceptor sensitivity in patients with syncopeClinical Autonomic Research, 2002
- Determination of plasma volume with indocyanine green in manLife Sciences, 1993
- Lack of variation in venous tone potentiates vasovagal syncope.Heart, 1992
- A practical, cost-effective, noninvasive system for cardiac output and hemodynamic analysisAmerican Heart Journal, 1988
- Geometric method for measuring body surface area: A height-weight formula validated in infants, children, and adultsThe Journal of Pediatrics, 1978