Items in AFP with MESH term: Hypotension, Orthostatic
Orthostatic Hypotension - Article
ABSTRACT: Orthostatic hypotension is a physical finding defined by the American Autonomic Society and the American Academy of Neurology as a systolic blood pressure decrease of at least 20 mm Hg or a diastolic blood pressure decrease of at least 10 mm Hg within three minutes of standing. The condition, which may be symptomatic or asymptomatic, is encountered commonly in family medicine. In healthy persons, muscle contraction increases venous return of blood to the heart through one-way valves that prevent blood from pooling in dependent parts of the body. The autonomic nervous system responds to changes in position by constricting veins and arteries and increasing heart rate and cardiac contractility. When these mechanisms are faulty or if the patient is hypovolemic, orthostatic hypotension may occur. In persons with orthostatic hypotension, gravitational opposition to venous return causes a decrease in blood pressure and threatens cerebral ischemia. Several potential causes of orthostatic hypotension include medications; non-neurogenic causes such as impaired venous return, hypovolemia, and cardiac insufficiency; and neurogenic causes such as multisystem atrophy and diabetic neuropathy. Treatment generally is aimed at the underlying cause, and a variety of pharmacologic or nonpharmacologic treatments may relieve symptoms.
ABSTRACT: Orthostatic hypotension is defined as a decrease in systolic blood pressure of 20 mm Hg or a decrease in diastolic blood pressure of 10 mm Hg within three minutes of standing when compared with blood pressure from the sitting or supine position. It results from an inadequate physiologic response to postural changes in blood pressure. Orthostatic hypotension may be acute or chronic, as well as symptomatic or asymptomatic. Common symptoms include dizziness, lightheadedness, blurred vision, weakness, fatigue, nausea, palpitations, and headache. Less common symptoms include syncope, dyspnea, chest pain, and neck and shoulder pain. Causes include dehydration or blood loss; disorders of the neurologic, cardiovascular, or endocrine systems; and several classes of medications. Evaluation of suspected orthostatic hypotension begins by identifying reversible causes and underlying associated medical conditions. Head-up tilt-table testing can aid in confirming a diagnosis of suspected orthostatic hypotension when standard orthostatic vital signs are nondiagnostic; it also can aid in assessing treatment response in patients with an autonomic disorder. Goals of treatment involve improving hypotension without excessive supine hypertension, relieving orthostatic symptoms, and improving standing time. Treatment includes correcting reversible causes and discontinuing responsible medications, when possible. Nonpharmacologic treatment should be offered to all patients. For patients who do not respond adequately to nonpharmacologic treatment, fludrocortisone, midodrine, and pyridostigmine are pharmacologic therapies proven to be beneficial.