What are the diagnostic criteria for Postural Orthostatic Tachycardia Syndrome (POTS)?

Diagnostic Criteria for Postural Orthostatic Tachycardia Syndrome (POTS)

POTS is diagnosed by demonstrating a sustained heart rate increase of ≥30 beats per minute (≥40 bpm in adolescents aged 12-19) within 10 minutes of standing or head-up tilt, in the absence of orthostatic hypotension, along with symptoms of orthostatic intolerance. 1, 2

Core Diagnostic Criteria

• Sustained heart rate increment ≥30 bpm within 10 minutes of standing or head-up tilt (for individuals aged 12-19 years, the required heart rate increment is ≥40 bpm) 1, 2
• Absence of orthostatic hypotension (no sustained systolic blood pressure drop of ≥20 mmHg or diastolic blood pressure drop of ≥10 mmHg) 1, 2
• Frequent symptoms of orthostatic intolerance during standing, with improvement on return to supine position 1
• Duration of symptoms for at least 3 months 1
• Absence of other conditions explaining sinus tachycardia (e.g., anemia, fever, dehydration, medications, hyperthyroidism) 1, 3

Diagnostic Testing Approach

• Perform a 10-minute active stand test with continuous monitoring 2

  • Measure blood pressure and heart rate after 5 minutes of lying supine
  • Record measurements immediately upon standing, and at 2,5, and 10 minutes after standing
  • Patient must stand quietly for the full 10 minutes as heart rate increase may take time to develop
  • Document any symptoms that occur during the test

• Alternative: Head-up tilt table testing if active stand test is inconclusive 1, 2

• Standing heart rate is often >120 bpm in patients with POTS 1, 2, 3

Clinical Symptoms of Orthostatic Intolerance

• Lightheadedness (most common symptom, reported in up to 97.6% of patients) 4
• Palpitations 1, 2
• Tremulousness 1
• Generalized weakness 1, 2
• Blurred vision 1, 2
• Fatigue 1, 2
• Cognitive difficulties or "brain fog" 2, 5
• Headache 1, 2
• Nausea 1

Exclusion of Alternative Diagnoses

• Rule out other causes of orthostatic symptoms and tachycardia 3, 6:
  • Dehydration
  • Anemia
  • Hyperthyroidism
  • Pheochromocytoma
  • Medications (sympathomimetics, anticholinergics)
  • Primary anxiety disorders
  • Inappropriate sinus tachycardia
  • Other cardiac arrhythmias

Common Associations and Comorbidities

• POTS is frequently associated with:
  • Deconditioning 1, 7
  • Recent infections 1, 7
  • Chronic fatigue syndrome 1, 3
  • Joint hypermobility syndrome/Ehlers-Danlos syndrome 1
  • Autoimmune disorders 5

Pathophysiologic Subtypes

• Neuropathic POTS: Partial dysautonomia with impaired sympathetically mediated vasoconstriction 3, 5
• Hypovolemic POTS: Reduced blood volume 3, 5
• Hyperadrenergic POTS: Excessive sympathetic drive 3, 5

Common Diagnostic Pitfalls

• Failure to perform the active stand test for the full 10 minutes may miss delayed heart rate increases 2, 6
• Not distinguishing POTS from inappropriate sinus tachycardia or other tachyarrhythmias 2, 6
• Overlooking medication effects that may mimic or exacerbate POTS symptoms 1, 3
• Diagnosing POTS based on symptoms alone without objective orthostatic testing 6, 4
• Not considering that POTS phenotypes cannot be distinguished based on symptoms alone; testing is necessary for proper classification 4

Special Considerations for COVID-19 Related POTS

• Post-COVID-19 POTS is defined as POTS that started during probable or confirmed acute COVID-19 and lasts ≥3 months 1
• The same diagnostic criteria apply to post-COVID POTS as to primary POTS 1