What is Postural Orthostatic Tachycardia Syndrome (POTS)?

From the Guidelines

POTS (Postural Orthostatic Tachycardia Syndrome) is a clinical syndrome characterized by a rapid heart rate increase of at least 30 beats per minute within 10 minutes of standing, without a significant drop in blood pressure, and is often accompanied by symptoms such as lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, exercise intolerance, and fatigue. According to the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1, POTS is defined as a clinical syndrome usually characterized by all of the following: 1) frequent symptoms that occur with standing; and 2) 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); and 3) the absence of OH (>20 mm Hg reduction in systolic BP). The standing heart rate is often >120 bpm.

Key Characteristics of POTS

• Rapid heart rate increase of at least 30 beats per minute within 10 minutes of standing
• No significant drop in blood pressure
• Symptoms such as lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, exercise intolerance, and fatigue
• Often affects young women between ages 15-50

Pathophysiology and Treatment

POTS occurs because the body fails to properly regulate blood flow when changing positions, causing blood to pool in the lower extremities and triggering an excessive heart rate response to maintain blood pressure. Treatment typically involves lifestyle modifications, including increased fluid intake, increased salt consumption, regular exercise, compression garments, and avoiding triggers like heat and prolonged standing. Medications may include beta-blockers, fludrocortisone, midodrine, or ivabradine to reduce heart rate or increase blood volume. As noted in the 2018 ESC guidelines for the diagnosis and management of syncope 1, POTS is characterized by an inappropriate heart rate increase without concomitant blood pressure fall, and likely mechanisms include severe deconditioning, immune-mediated processes, excessive venous pooling, and hyperadrenergic state.

Quality of Life and Mortality

POTS can significantly impact quality of life through symptoms like dizziness, fatigue, brain fog, and exercise intolerance. While the condition itself is not typically life-threatening, it can have a significant impact on daily life and activities. As stated in the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1, and further supported by the 2018 ESC guidelines for the diagnosis and management of syncope 1, the focus of treatment should be on managing symptoms and improving quality of life.

From the Research

Definition and Characteristics of Postural Orthostatic Tachycardia Syndrome (POTS)

• POTS is a form of cardiovascular autonomic disorder characterized by orthostatic intolerance and a symptomatic increase in heart rate upon standing 2, 3, 4, 5, 6.
• It is a clinically heterogeneous disorder with multiple contributing pathophysiologic mechanisms, including partial autonomic neuropathy, hypovolemia, and hyperadrenergic state 5.
• The syndrome affects younger individuals, typically between 15-45 years old, with a distinct female predominance of approximately 80% 4.
• Common complaints include dizziness, weakness, rapid heartbeat, and palpitation on standing, as well as physical deconditioning, reduced exercise capacity, headache, 'brain fog', dyspnoea, gastrointestinal disorders, and musculoskeletal pain 4.

Diagnosis and Treatment of POTS

• The diagnosis of POTS is typically established through a head-up tilt test with non-invasive beat-to-beat haemodynamic monitoring, or a standing test with serum norepinephrine levels and red-cell volumes 3, 4.
• Treatment approaches are varied and depend on the underlying pathophysiologic mechanism, with a focus on lifestyle modifications, including increased fluid and salt intake, compression garment use, physical reconditioning, and postural training 2, 3, 5.
• Pharmacologic therapies are used to manage specific symptoms, such as beta-blockers for hyperadrenergic POTS, and agents that enhance vascular tone, like pyridostigmine and midodrine, for neuropathic POTS 2, 3, 5.
• Exercise training and volume expansion are also effective in managing hypo-volemic POTS 5.

Pathophysiology and Management Strategies

• The pathophysiology of POTS is complex and multifactorial, with three primary phenotypes: hyperadrenergic, neuropathic, and hypovolemic, each requiring tailored management strategies 2, 5.
• The approach to treatment centers on addressing the underlying pathophysiologic mechanism, with individualized treatment regimens 5.
• A multidisciplinary approach, encompassing pharmacological treatments, lifestyle modifications, and psychological support, is necessary for effective management of POTS 6.