Postprandial orthostatic hypotension

Specialty: Geriatrics.

• postprandial tension drop
• postprandial hypotension in the elderly
• digestion syncope

Why it occurs

• Massive splanchnic blood sequestration mediated by the release of vasoactive gastrointestinal peptides after carbohydrate ingestion
• Primary baroreflex autonomic dysfunction (Parkinson's disease, Lewy body dementia) or secondary (diabetic or amyloid neuropathy)
• Administration of antihypertensive or diuretic drugs at times coinciding with main meals
• Structural rigidity of the major arterial vessels that prevents rapid compensatory vasoconstriction
• Alcohol consumption during meals, which exerts a synergistic systemic vasodilator effect

Initial workup

Serial measurement of blood pressure and heart rate in the supine position and after 1, 3 and 5 minutes of active standing, performed before eating and 30 to 60 minutes after a standardized carbohydrate intake; 24-hour ambulatory blood pressure monitoring (ABPM); 12-lead electrocardiogram; transthoracic echocardiogram to assess systolic or diastolic dysfunction and rule out severe aortic stenosis; complete blood count to rule out anemia as an aggravating factor.

Standard management

• Midodrine — 2.5 mg to 5 mg orally administered 30 to 45 minutes before main meals, limiting its intake to daytime hours to avoid severe nocturnal supine hypertension
• Fludrocortisone — 0.1 mg orally daily in the morning, to expand total plasma volume through sodium retention, closely monitoring the appearance of edema, hypokalemia or signs of decompensated heart failure
• Acarbose (50 mg orally at the beginning of carbohydrate-rich meals to delay gastric emptying and glucose absorption, reducing the secretion of splanchnic peptides).