Postural Orthostatic Tachycardia Syndrome (POTS)
POTS is a form of cardiovascular autonomic disorder characterized by orthostatic intolerance with an inappropriate tachycardia upon standing (heart rate increase ≥30 bpm or ≥40 bpm in those 12-19 years of age within 10 minutes), absence of orthostatic hypotension, and chronic symptoms of orthostatic intolerance for at least 3 months. 1
Diagnostic Criteria
- Heart rate increase ≥30 bpm (≥40 bpm in ages 12-19) within 10 minutes of standing
- Absence of orthostatic hypotension (>20 mmHg reduction in systolic BP)
- Chronic symptoms of orthostatic intolerance for at least 3 months
- Optimal diagnostic cutoffs:
- Tilt test: heart rate increase of 38 bpm
- Active stand: heart rate increase of 29 bpm 1
Pathophysiology
POTS has three primary phenotypes, each with distinct mechanisms:
- Neuropathic POTS: Partial sympathetic neuropathy causing impaired vasoconstriction during orthostatic stress 1, 2
- Hyperadrenergic POTS: Excessive sympathetic drive or impaired norepinephrine reuptake 1, 2
- Hypovolemic POTS: Reduced blood volume, often triggered by dehydration and physical deconditioning 1, 2
Common Etiologies and Associations
- Post-viral infections (including COVID-19) - up to 40% of cases 1
- Autoimmune disorders 1
- Genetic predisposition 1
- Hypermobile Ehlers-Danlos syndrome (hEDS) - 37.5% of hEDS patients report POTS 1
- Mast cell activation syndrome (MCAS) - 25.2% of MCAS patients have POTS 1
- Chronic fatigue syndrome 1
Management Approach
Non-Pharmacological Interventions (First-Line)
Increased fluid and salt intake:
- 10-12g salt daily (unless contraindicated)
- 2-3 liters of water or electrolyte-balanced fluid daily
- Caution in patients with cardiac dysfunction, heart failure, uncontrolled hypertension, or chronic kidney disease 1
Compression garments:
- Waist-high compression stockings (30-40 mmHg pressure) to reduce venous pooling 1
Structured exercise program:
- Begin with recumbent or semi-recumbent exercise (rowing, swimming, recumbent cycling)
- Start with 5-10 minutes daily at a level allowing speech in full sentences
- Gradually increase duration by approximately 2 minutes per day each week 1
Pharmacological Therapy (Based on POTS Phenotype)
Neuropathic POTS:
Hyperadrenergic POTS:
Hypovolemic POTS:
Refractory Cases:
- Droxidopa: Beneficial in neurogenic orthostatic hypotension
- Octreotide: May be beneficial in refractory cases 1
Monitoring and Follow-up
- Monitor for supine hypertension when using midodrine
- Check electrolytes (sodium, potassium, magnesium) and renal function, especially for patients on fludrocortisone
- Evaluate treatment response with standing heart rate and symptom improvement
- Follow-up testing every 3-6 months or when changing treatment regimens
- Immediate testing during significant symptom exacerbations 1
Important Clinical Considerations
- POTS is not associated with increased mortality, with many patients improving over time with proper treatment 3
- Consider Spontaneous Intracranial Hypotension (SIH) in the differential diagnosis for patients with orthostatic headaches 1
- Currently, there are no FDA-approved medications specifically for POTS treatment 4
- Seek immediate medical attention for syncope, severe chest pain, sustained palpitations unrelieved by rest, shortness of breath at rest, or palpitations with dizziness, confusion, or altered mental status 1
Common Pitfalls
- Failing to recognize POTS as a multifactorial disorder with overlapping phenotypes
- Not testing serum tryptase during symptom flares (1-4 hours after) when MCAS is suspected
- Inadequate attention to non-pharmacological interventions, which are the foundation of treatment
- Not adjusting medication timing to avoid peak effects during high-risk activities
- Overlooking the need to reduce or withdraw medications that may exacerbate hypotension