What is Postural Orthostatic Tachycardia Syndrome (POTS)?

From the Guidelines

Postural Orthostatic Tachycardia Syndrome (POTS) should be managed with a combination of non-pharmacological and pharmacological approaches, prioritizing increased fluid intake, salt consumption, compression garments, and graduated exercise programs, as well as medications like beta-blockers, fludrocortisone, and midodrine, to control symptoms and improve quality of life.

Pathophysiology and Symptoms

POTS is characterized by an abnormal increase in heart rate when moving from a lying to standing position, accompanied by symptoms like dizziness, fatigue, and brain fog 1. The pathophysiology is debated and likely heterogeneous, involving deconditioning, immune-mediated processes, excessive venous pooling, and a hyperadrenergic state 1. Symptoms typically develop upon standing, are relieved by sitting or lying, and may be worse in the morning, with heat exposure, and after meals or exertion 1.

Treatment Approaches

Treatment typically begins with non-pharmacological approaches, including:

• Increased fluid intake (2-3 liters daily) and salt consumption (8-10g daily)
• Compression garments for the lower body
• A graduated exercise program focusing on recumbent exercises initially Medications commonly prescribed include:
• Beta-blockers like propranolol (10-20mg twice daily) or metoprolol (25-50mg twice daily) to control heart rate
• Fludrocortisone (0.1-0.2mg daily) to increase blood volume
• Midodrine (2.5-10mg three times daily) to constrict blood vessels Some patients may also benefit from ivabradine (2.5-7.5mg twice daily) for heart rate control without affecting blood pressure.

Key Considerations

POTS occurs when the autonomic nervous system fails to properly regulate blood vessel constriction upon standing, causing blood pooling in the lower extremities and requiring increased heart rate to maintain adequate circulation 1. Treatment effectiveness varies between individuals, and a combination approach is often most successful. It is essential to consider the individual patient's symptoms, medical history, and response to treatment when developing a management plan 1.

From the Research

Definition and Characteristics of POTS

• Postural Orthostatic Tachycardia Syndrome (POTS) is a form of cardiovascular autonomic disorders characterized by orthostatic intolerance and a symptomatic increase in heart rate upon standing 2.
• POTS is a clinically heterogeneous disorder with multiple contributing pathophysiologic mechanisms manifesting as symptoms of orthostatic intolerance in the setting of orthostatic tachycardia without orthostatic hypotension 3.
• A typical patient with POTS is a female of child-bearing age, who often first displays symptoms in adolescence, and the onset of POTS may be precipitated by immunological stressors such as a viral infection 4.

Pathophysiology and Phenotypes of POTS

• The pathophysiology of POTS is complex, multifactorial, and involves various mechanisms, including partial autonomic neuropathy, hypovolemia, and hyperadrenergic state 3.
• Three primary POTS phenotypes have been identified: hyperadrenergic, neuropathic, and hypovolemic, each requiring tailored management strategies 2.
• The pathophysiology of the syndrome is incompletely understood and undoubtedly multifaceted, involving a variety of pathophysiologies in the abnormal postural tachycardia response 4.

Diagnosis and Management of POTS

• The evaluation of a patient with suspected POTS should seek to establish the diagnosis, identify co-morbid conditions, and exclude conditions that could cause or mimic the syndrome 4.
• Management typically begins with patient education and non-pharmacologic treatment options, including lifestyle modifications such as increased fluid and salt intake, compression garment use, physical reconditioning, and postural training 2.
• Various medications are often used to address specific symptoms, but there are currently no FDA-approved medications for the treatment of POTS, and evidence for many of the medications used to treat POTS is not robust 4, 5.

Treatment Approaches for POTS

• First-line treatment for all patients focuses on lifestyle modifications, and pharmacologic therapies are primarily used to manage specific symptoms 2.
• Beta-blockers are an effective option for hyperadrenergic POTS, while agents that enhance vascular tone, such as pyridostigmine and midodrine, are used for neuropathic POTS 2, 3.
• Volume expansion and exercise are the main treatment strategies for hypovolemic POTS 2, 3.
• Experimental therapies, such as cardiac neuromodulation, are being explored, and supplemental therapies like iron, vitamin D, and α lipoic acid may be used 5.