Orthostatic Hypotension

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Symptoms of reduced cerebral perfusion upon assuming an upright position—dizziness to frank syncope

• Marked fall in blood pressure within 3 minutes of standing (> 20 mm Hg systolic or > 10 mm Hg diastolic)

GENERAL CONSIDERATIONS

• This disorder may be symptomatic or asymptomatic

• Symptoms are worse in the morning, after meals, and after exercise

• Usual causes include volume depletion (usually secondary to diuretics), vasodilators, and neurogenic causes such as primary and secondary causes of autonomic failure

• Elderly population is most commonly affected owing to reduced baroreceptor sensitivity, impaired thirst mechanism, and reduced cerebral blood flow

• Parkinson’s disease and multiple-system atrophy (Shy-Drager syndrome) may cause orthostatic hypotension

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Lightheadedness

• Dizziness

• Blurred vision

• Weakness

• Palpitation

• Tremulousness

• Syncope

PHYSICAL EXAM FINDINGS

• Postural drop in blood pressure of > 20 mm Hg systolic or > 10 mm Hg diastolic

• Features of neurologic disease if present

DIFFERENTIAL DIAGNOSIS/CAUSES

• Fluid loss, anemia, dehydration

• Primary autonomic dysfunction: Shy-Drager syndrome

• Secondary dysautonomia:

  • – Parkinson’s disease

  • – Diabetes mellitus

  • – Amyloidosis

  • – Human immunodeficiency virus infection

  • – Multiple sclerosis

• Vasoactive medications:

  • – Antihypertensive agents

  • – Ethanol

  • – Psychoactive drugs

• Advanced age: akinetic falling spells of the aged

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• CBC, basic metabolic panel

ELECTROCARDIOGRAPHY

• ECG to screen for underlying conduction disease

IMAGING STUDIES

• None required for diagnosis

DIAGNOSTIC PROCEDURES

• Autonomic nervous system studies may be indicated

TREATMENT

CARDIOLOGY REFERRAL

• Seldom required unless initial management is not successful or diagnosis is in question

HOSPITALIZATION CRITERIA

• Syncope secondary to profound volume depletion

• Recurrent syncope

• Trauma secondary to syncope

MEDICATIONS

• Treat underlying cause if possible

• Wear elastic stockings

• Maintain adequate salt and water intake

• Administer fludrocortisone 0.1–1.0 mg PO daily

• Give alpha₁-adrenergic agonists, eg, midodrine 10 mg 3 times PO daily

THERAPEUTIC PROCEDURES

• None required

MONITORING

• Orthostatic blood pressure monitoring after initiation of treatment

DIET AND ACTIVITY

• Liberal salt intake to maintain euvolemia

ONGOING MANAGEMENT

HOSPITAL DISCHARGE CRITERIA

• After initiation of therapy

FOLLOW-UP

• Initially 2 weeks; after that 3 months, depending on response

COMPLICATIONS

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