A 66-year-old man arrives at the emergency department after experiencing several bouts of lightheadedness and a recent fall. The symptoms are most noticeable when he first gets out of bed in the morning. The patient is on medication for high blood pressure, stable angina pectoris, gout, and benign prostate hyperplasia. He also has right knee osteoarthritis and uses nonsteroidal anti-inflammatory drugs on occasion. In the supine position, his blood pressure and pulse rate are 120/80 mm Hg and 70/min, respectively, and 90/60 mm Hg and 87/min when standing. The cardiopulmonary exam is normal. Blockade of which of the following receptors is most likely contributing to this patient's current condition?

Question

Quizplus · Accepted Answer

Eductional Objective: Orthostatic hypotension, defined as a decrease in systolic (>20 mm Hg) or diastolic (>10 mm Hg) blood pressure upon standing from a supine position, is a common cause of lightheadedness and syncope. Orthostatic hypotension is commonly caused by medications (alpha 1-adrenergic antagonists, diuretics), volume depletion, and autonomic dysfunction.

A 66-Year-Old Man Arrives at the Emergency Department After Experiencing