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Background: Supine hypertension and post-prandial hypotension are associated with chronic autonomic failure, and may prove resistant to treatment. We determined if the hypotensive effects of food could be utilised to reduce supine hypertension in pure autonomic failure (PAF)., Methods: A subject with long-standing PAF, documented supine hypertension and post-prandial hypotension had a gastrostomy tube placed for dysphagia. We compared 24-hour ambulatory blood pressure recordings before and after nocturnal gastrostomy feeding., Results: Gastrostomy feeding was associated with resolution of supine hypertension and normalization of circadian BP rhythm., Conclusions: Gastrostomy feeding at night may help reduce supine hypertension in autonomic failure.

Background: The oral ingestion of water increases seated blood pressure in chronic autonomic failure although the mechanisms of this effect remain unclear. Recent studies in normal subjects suggest that oropharyngeal stimulation during swallowing may be of greater importance in causing a rise in blood pressure (BP) than the gastric effects of water. We therefore assessed the haemodynamic effects of water instilled directly into the stomach via a gastrostomy tube in pure autonomic failure (PAF)., Methods: The subject had longstanding (>20 years) PAF. A gastrostomy tube had been previously placed because of dysphagia. Distilled water (480 ml) was instilled in the seated position with BP and heart rate (HR) measured over the following 40 min while the subject remained seated. Systolic and diastolic BP (SBP and DBP) and heart rate (HR) were recorded intermittently every 3 min with a Dinamap automated syphgmomanometer and continuously using a Portapres device. Subsequent model flow analysis of the Portapres data provided beat-to-beat estimates of cardiac output, stroke volume, and total peripheral resistance (TPR). Subjective orthostatic symptoms were recorded before and after water., Results: Seated SBP and DBP increased after water instillation with increases first noted between 5 and 8 min after the water had been instilled. The BP remained elevated until 35 min post water increase over baseline being +36.5 mm Hg SBP and +24.3 mm Hg DBP. HR, cardiac output, and stroke volume remained unchanged during the study. Total peripheral resistance (TPR) increased post water. These results are similar to those reported in a recent study involving oral ingestion of 480 ml of water in PAF subjects., Conclusions: Instilling water directly into the stomach in a patient with PAF resulted in similar haemodynamic responses to those seen when water is taken orally. Thus, oropharyngeal factors and swallowing do not appear to be essential in the generation of the water pressor effect in autonomic failure.