How should I be tested for postural orthostatic tachycardia syndrome (POTS)?

How to Test for POTS (Postural Orthostatic Tachycardia Syndrome)

Start with a 10-minute active stand test with continuous heart rate and blood pressure monitoring—this is your first-line diagnostic test and is sufficient for most patients. 1, 2, 3

Diagnostic Criteria You're Looking For

The diagnosis requires all three of the following:

• Heart rate increase of ≥30 bpm within 10 minutes of standing (or ≥40 bpm if the patient is 12-19 years old) 1, 2
• Absence of orthostatic hypotension (no sustained drop of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing) 1, 2
• Symptoms of orthostatic intolerance that appear on standing and improve when seated or lying down—including lightheadedness, palpitations, tremulousness, generalized weakness, fatigue, blurred vision, or exercise intolerance 1

Note that the standing heart rate often exceeds 120 bpm in POTS patients, but this is not required for diagnosis—the increment (≥30 bpm) is what matters. 1

How to Perform the Active Stand Test

Pre-Test Preparation

• Patient should fast for 3 hours before testing 1, 3
• Avoid nicotine, caffeine, theine, or taurine-containing drinks on the day of examination 1, 3
• Perform testing in a quiet, temperature-controlled environment (21-23°C) 1, 3
• Ideally test before noon 1, 3

Testing Protocol

1. Have the patient lie supine for 5 minutes, then measure baseline heart rate and blood pressure 1, 2
2. Patient stands up and remains standing quietly without movement 1
3. Measure heart rate and blood pressure immediately upon standing, then at 2,5, and 10 minutes 1, 2
4. Document all symptoms that occur during the test 1, 2
5. Complete the full 10 minutes—heart rate increases may be delayed, and stopping early will miss cases 1, 2

Essential Laboratory Workup Before Confirming POTS

Before attributing symptoms to POTS, exclude mimicking conditions with:

• 12-lead ECG to rule out arrhythmias or conduction abnormalities 2, 3
• Thyroid function tests to exclude hyperthyroidism 2, 3
• Complete blood count to evaluate for anemia 2, 3
• Basic metabolic panel for electrolyte abnormalities and renal function 2, 3
• Hemoglobin A1c to screen for diabetes causing autonomic dysfunction 2

When to Proceed to Tilt-Table Testing

If the active stand test is inconclusive but clinical suspicion remains high, perform head-up tilt-table testing at 60-70 degrees for 20-45 minutes, using the same heart rate and blood pressure criteria. 1, 3 This is particularly useful to distinguish POTS from delayed orthostatic hypotension. 1

Common Diagnostic Pitfalls to Avoid

• Not completing the full 10 minutes of standing—delayed heart rate increases will be missed 1, 2
• Using adult criteria (≥30 bpm) in adolescents aged 12-19—this leads to overdiagnosis; use ≥40 bpm instead 1
• Failing to exclude orthostatic hypotension—POTS can only be diagnosed when orthostatic hypotension is absent 1, 2
• Not excluding secondary causes such as dehydration, medications (especially cardioactive drugs, diuretics, vasodilators), primary anxiety disorders, or eating disorders 1
• Testing under improper conditions—not maintaining fasting, allowing caffeine intake, or testing in a non-controlled environment can affect results 1, 3

When to Consider Testing for POTS

Testing should be targeted to patients presenting with clinical manifestations of POTS, not performed universally. 4 Consider testing when patients report:

• Dizziness, lightheadedness, or weakness that worsens with standing 1, 5
• Palpitations or rapid heartbeat on standing 1, 5
• Fatigue, exercise intolerance, or physical deconditioning 1, 5
• "Brain fog" or cognitive difficulties 1
• Symptoms that improve when sitting or lying down 1

In patients with hypermobile Ehlers-Danlos syndrome or hypermobility spectrum disorders, testing for POTS should be considered if they have refractory GI symptoms and report orthostatic intolerance, after excluding medication side effects and attempting lifestyle modifications (adequate hydration and physical exercise). 4

Screening for Associated Conditions

Based on clinical presentation, consider targeted testing for:

• Joint hypermobility using the Beighton score (≥6/9 points in pre-pubertal children) 1, 3
• Recent infection or trauma as a precipitating factor 1
• Mast cell activation syndrome if the patient has episodic symptoms involving 2 or more physiological systems (cutaneous, GI, cardiac, respiratory, neuropsychiatric) 4

When to Expand to Comprehensive Autonomic Testing

Reserve comprehensive autonomic function testing (beat-to-beat BP and ECG monitoring, Valsalva maneuver, 24-hour ambulatory BP monitoring, sudomotor testing) for atypical presentations or when the diagnosis remains uncertain after initial testing. 3 Red flags for atypical POTS include older age at onset, male sex, prominent syncope (which is rare in typical POTS), or examination abnormalities other than joint hyperextensibility. 6