What is Postural Orthostatic Tachycardia Syndrome (POTS)?
Postural Orthostatic Tachycardia Syndrome (POTS) is a clinical syndrome characterized by a sustained heart rate increase of ≥30 bpm (or ≥40 bpm in patients aged 12-19 years) within 10 minutes of standing, occurring without orthostatic hypotension, accompanied by frequent symptoms of orthostatic intolerance that improve when lying down. 1
Core Diagnostic Criteria
POTS requires all five components to be present for at least 3 months 1:
- Heart rate criteria: Sustained increase of ≥30 bpm within 10 minutes of standing (≥40 bpm for ages 12-19 years), with standing heart rate often exceeding 120 bpm 2, 1
- Blood pressure criteria: Absence of orthostatic hypotension (no sustained systolic BP drop ≥20 mmHg or diastolic drop ≥10 mmHg) 1, 3
- Symptom profile: Frequent symptoms of orthostatic intolerance during standing that rapidly improve upon returning to supine position 1
- Duration requirement: Symptoms must persist for at least 3 months 2, 1
- Exclusion of alternative causes: Must rule out conditions like anemia, hypoxia, hypotension, fever, hyperthyroidism, pheochromocytoma, and cardioactive drugs 2
Clinical Presentation
Postural Symptoms
The hallmark symptoms occur specifically with standing and include 2, 1:
- Lightheadedness and dizziness
- Palpitations and tremulousness
- Generalized weakness
- Blurred vision or tunnel vision
- Exercise intolerance
- Fatigue and lethargy
Non-Postural Symptoms
POTS also presents with symptoms not tied to specific postures 2:
- Gastrointestinal: bloating, nausea, diarrhea, abdominal pain
- Systemic: chronic fatigue, sleep disturbance, migraine headaches
- Cognitive: "brain fog" and difficulty concentrating 3
- Chest pain and shortness of breath 4
Important Clinical Distinction
Syncope is rare in POTS and typically occurs only when vasovagal reflex activation is triggered, not from POTS itself. 1 This distinguishes POTS from other causes of syncope.
Patient Demographics and Associations
POTS predominantly affects young women and may be associated with 1:
- Recent infection or trauma
- Joint hypermobility syndrome
- Chronic fatigue syndrome
- Severe deconditioning
Pathophysiology
Three primary POTS phenotypes have been identified, each with distinct mechanisms 5:
- Hyperadrenergic POTS: Excessive norepinephrine production or impaired reuptake leading to sympathetic overactivity 5
- Neuropathic POTS: Impaired vasoconstriction during orthostatic stress due to sympathetic denervation 5, 4
- Hypovolemic POTS: Central hypovolemia and reflex tachycardia, often triggered by dehydration and physical deconditioning 5, 4
Common Pitfalls in Recognition
Healthcare providers should be aware that 2:
- In older adults, the prevalence of syncope as a presenting symptom ranges from 0.8% to 2.4% in emergency departments, and POTS may overlap with falls, making it difficult to distinguish one from the other
- The diagnosis is made primarily through thorough history, physical examination, and eyewitness observation when available 2
- POTS can develop as a post-acute sequela of COVID-19 (PASC POTS), persisting ≥3 months after initial infection 2