What is Postural Orthostatic Tachycardia Syndrome (POTS)?

From the Guidelines

POTS (Postural Orthostatic Tachycardia Syndrome) is a condition characterized by a rapid heart rate increase of at least 30 beats per minute within 10 minutes of standing, often accompanied by dizziness, lightheadedness, fatigue, brain fog, and sometimes fainting, as defined by the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1. The primary symptoms of POTS include:

• Frequent symptoms that occur with standing, such as lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, exercise intolerance, and fatigue
• An increase in heart rate of ≥30 bpm during a positional change from supine to standing (or ≥40 bpm in those 12–19 years of age)
• The absence of orthostatic hypotension (>20 mm Hg reduction in systolic BP) POTS is managed through:
• Increased fluid intake (2-3 liters daily)
• Increased salt consumption (3-10g daily)
• Compression garments for the lower body
• Gradual exercise programs Medications may include:
• Beta-blockers like propranolol (10-40mg)
• Fludrocortisone (0.1-0.2mg daily)
• Midodrine (2.5-10mg three times daily) POTS occurs because the autonomic nervous system fails to properly regulate blood vessel constriction when standing, causing blood to pool in the lower body, as noted in the 2022 ACC expert consensus decision pathway on cardiovascular sequelae of COVID-19 in adults 1. This condition primarily affects women between 15-50 years old and can be triggered by viral illnesses, pregnancy, or trauma, though it's often manageable with proper treatment, as discussed in the 2018 ESC guidelines for the diagnosis and management of syncope 1.

From the Research

Definition of POTS

• Postural Orthostatic Tachycardia Syndrome (POTS) is defined by a heart rate increment of 30 beats/min or more within 10 minutes of standing or head-up tilt in the absence of orthostatic hypotension 2
• The standing heart rate is often 120 beats/min or higher 2
• POTS is characterized by an excessive increase in heart rate upon standing associated with light-headedness, headaches, chest pain, shortness of breath, and brain fog 3

Pathophysiology of POTS

• The pathophysiology of POTS is heterogeneous and includes impaired sympathetically mediated vasoconstriction, excessive sympathetic drive, volume dysregulation, and deconditioning 2
• The 3 major hypotheses about the pathophysiology of POTS are autoimmunity, abnormally increased sympathetic activity, and sympathetic denervation leading to central hypovolemia and reflex tachycardia 3
• An exaggerated norepinephrine response with standing is often present in POTS 4

Symptoms of POTS

• Patients with POTS often experience a constellation of symptoms including fatigue, exercise intolerance, and gastrointestinal distress 5
• Other symptoms may include cerebral hypoperfusion, excessive sympathoexcitation, functional gastrointestinal or bladder disorders, chronic headache, fibromyalgia, and sleep disturbances 2
• The tachycardia response in POTS may be central to the pathophysiology of POTS symptoms 4

Diagnosis and Treatment 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 5
• Management typically begins with patient education and non-pharmacologic treatment options 5
• Various medications are often used to address specific symptoms, including fludrocortisone, beta blockers, midodrine, and selective serotonin reuptake inhibitors 6