What is Postural Orthostatic Tachycardia Syndrome (POTS)?
POTS is a chronic autonomic disorder characterized by an excessive heart rate increase of ≥30 bpm (≥40 bpm in adolescents aged 12-19 years) within 10 minutes of standing, occurring without orthostatic hypotension, accompanied by symptoms of orthostatic intolerance that improve when lying down. 1, 2
Core Diagnostic Features
POTS requires all five components to be present simultaneously for at least 3 months 2:
- Heart rate criteria: Sustained increase of ≥30 bpm within 10 minutes of standing (≥40 bpm for ages 12-19), with standing heart rate often exceeding 120 bpm 1, 2
- Blood pressure criteria: Explicit absence of orthostatic hypotension (no sustained systolic BP drop ≥20 mmHg or diastolic drop ≥10 mmHg within 3 minutes of standing) 1, 2, 3
- Symptom profile: Frequent symptoms of orthostatic intolerance during standing that rapidly improve upon returning to supine position 2
- Duration requirement: Symptoms must persist for at least 3 months (6 months in children per some guidelines) 4, 1
- Exclusion criteria: Absence of other conditions explaining the tachycardia such as anemia, hyperthyroidism, fever, dehydration, medications, or severe deconditioning 4, 1
Clinical Presentation and Symptoms
The typical POTS patient is a young woman of childbearing age (15-45 years old), with approximately 80% female predominance, often with symptom onset in adolescence. 5, 6
Common symptoms include 1, 2, 5:
- Cardiovascular: Lightheadedness, palpitations, tremulousness, rapid heartbeat upon standing 1, 2
- Neurological: Blurred vision, "brain fog," cognitive difficulties, headache 1, 5
- Physical: Generalized weakness, fatigue, lethargy, exercise intolerance 1, 5
- Other: Chest pain, gastrointestinal dysfunction, musculoskeletal pain 1, 5
Syncope is rare in POTS and typically occurs only when vasovagal reflex activation is triggered, not from POTS itself. 2
Precipitating Factors and Associated Conditions
POTS onset is typically precipitated by immunological stressors 5, 6:
- Viral infection (including COVID-19) 4, 5, 6
- Vaccination 5
- Trauma, pregnancy, or surgery 5
- Psychosocial stress 5
POTS may be associated with joint hypermobility syndrome, chronic fatigue syndrome, or severe deconditioning. 4, 2
Pathophysiology
POTS represents a heterogeneous clinical syndrome with multiple underlying pathophysiological mechanisms converging as a final common pathway. 7, 6
Three primary phenotypes have been identified 8:
- Hyperadrenergic POTS: Excessive norepinephrine production or impaired reuptake leading to sympathetic overactivity 8
- Neuropathic POTS: Partial sympathetic denervation resulting in impaired vasoconstriction during orthostatic stress 8, 7
- Hypovolemic POTS: Central hypovolemia with reflex tachycardia, often triggered by dehydration and physical deconditioning 8, 7
Prognosis and Natural History
POTS is not associated with mortality, and approximately 50% of patients spontaneously recover within 1-3 years after diagnosis. 7, 5
The condition significantly impairs health-related quality of life, with many patients experiencing physical deconditioning and reduced exercise capacity 8, 5. However, with proper diagnosis and treatment, many patients improve to some degree over time 7.
Prevalence
The prevalence of POTS ranges between 0.2% and 1.0% in developed countries. 5