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Postprandial hypotension in elderly patients with unexplained syncope

1995; American Medical Association; Volume: 155; Issue: 9 Linguagem: Inglês

10.1001/archinte.155.9.945

1538-3679

R. W. Jansen,

Heart Rate Variability and Autonomic Control

Backgrounds Syncope in older patients may be caused by a variety of disorders, including hypotension, but fre quently remains unexplained.Postprandial hypoten sion is a common disorder of blood pressure regulation in the elderly.Objective: To determine the pathogenic mechanisms and potential role of postprandial hypotension in el derly patients with otherwise unexplained syncope.Methods: We studied 16 elderly patients with unex plained syncope and nine elderly controls.Blood pres sure, heart rate, forearm vascular resistance, plasma norepinephrine level, and cardiac and splanchnic blood volumes were measured before and after a 1680-1<J meal.Results: Eight elderly patients with syncope had post prandial hypotension, with a decline in supine mean arterial blood pressure of 17±2 mm Hg after a meal (PC.001).The blood pressure remained unchanged after the meal in the other patients with syncope and the controls.In patients with postprandial hypo ten-fell r while it remained unchanged in the other groups.Heart rate and plasma norepinephrine level increased to a similar extent in all three groups.Forearm vascu lar resistance increased o i n q eets.Splanchnic blood volume increased by 26% (PC.Ol) in patients with syncope who had postprandial hypotension and by 22% (PC.O l) in control s Splanchnic blood volume remained unchanged in the patients w ith syncope w ithout p o stp ran d ial hypotension.Conclusions: Postprandial hypotension may be an im portant causative factor in elderly patients with unex plained syncope.The evaluation of syncope in elderly patients should therefore include blood pressure mea surements surrounding a meal.Elderly patients with syn cope who have postprandial hypotension fail to main tain systemic vascular resistance, probably because splanchnic blood pooling without a compensatory in crease in peripheral vascular resistance.