From the Guidelines
Postural Orthostatic Tachycardia Syndrome (POTS)
POTS stands for Postural Orthostatic Tachycardia Syndrome, a condition characterized by a rapid increase in heart rate and other symptoms that occur upon standing, typically diagnosed when a person's heart rate increases by 30 beats per minute or more within 10 minutes of standing, or 40 beats per minute or more in those 12-19 years of age 1.
Key Characteristics
- Rapid heart rate increase: An increase in heart rate of ≥30 bpm during a positional change from supine to standing (or ≥40 bpm in those 12–19 y of age) 1.
- Symptoms upon standing: Frequent symptoms that occur with standing, such as lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, exercise intolerance, and fatigue 1.
- Absence of orthostatic hypotension: The absence of a significant drop in blood pressure (>20 mm Hg reduction in systolic BP) upon standing 1.
Associated Symptoms
- Dizziness and lightheadedness
- Palpitations
- Tremulousness
- Generalized weakness
- Blurred vision
- Exercise intolerance
- Fatigue
- Bloating
- Nausea
- Diarrhea
- Abdominal pain
- Migraine headaches
- Sleep disturbance 1
Pathophysiology
The pathophysiology of POTS is debated and likely heterogeneous, with proposed mechanisms including deconditioning, immune-mediated processes, excessive venous pooling, and a hyperadrenergic state 1.
From the Research
Definition and Characteristics of POTS
- Postural Orthostatic Tachycardia Syndrome (POTS) is an autonomic disorder characterized by an exaggerated increase in heart rate that occurs during standing, without orthostatic hypotension 2.
- POTS is a form of cardiovascular autonomic disorders characterized by orthostatic intolerance and a symptomatic increase in heart rate upon standing, which can significantly impair patients' quality of life 3.
- Patients with POTS complain of symptoms of tachycardia, exercise intolerance, lightheadedness, extreme fatigue, headache, and mental clouding 4.
Pathophysiology and Phenotypes of POTS
- The pathophysiology of POTS is complex and multifactorial, with three primary phenotypes: hyperadrenergic, neuropathic, and hypovolemic, each requiring tailored management strategies 3.
- Hyperadrenergic POTS is characterized by excessive norepinephrine production or impaired reuptake, leading to sympathetic overactivity 3.
- Neuropathic POTS results from impaired vasoconstriction during orthostatic stress, while hypovolemic POTS is often triggered by dehydration and physical deconditioning 3.
Diagnosis and Management of POTS
- The diagnosis of POTS is established through a tilt-table test, standing test, serum norepinephrine levels, and red-cell volumes 2.
- First-line treatment for all patients focuses on lifestyle modifications, including increased fluid and salt intake, compression garment use, physical reconditioning, and postural training 3.
- Pharmacologic therapies are primarily used to manage specific symptoms, with beta-blockers being effective in hyperadrenergic POTS, and agents that enhance vascular tone being used in neuropathic POTS 3, 5.