What are the diagnostic criteria for Postural Orthostatic Tachycardia Syndrome (POTS)?

From the Guidelines

Postural Orthostatic Tachycardia Syndrome (POTS) is diagnosed when a patient experiences a sustained heart rate increase of at least 30 beats per minute (or ≥40 beats per minute in individuals aged 12-19 years) within 10 minutes of standing or during a head-up tilt test, without orthostatic hypotension (a drop in blood pressure >20/10 mmHg). To diagnose POTS, the following criteria must be met:

• A sustained heart rate increase of at least 30 beats per minute (or ≥40 beats per minute in individuals aged 12-19 years) within 10 minutes of standing or during a head-up tilt test
• Absence of orthostatic hypotension (a drop in blood pressure >20/10 mmHg)
• Presence of chronic symptoms that worsen with standing, such as lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, fatigue, and exercise intolerance
• Symptoms must persist for at least 3 months
• Other causes of orthostatic symptoms or tachycardia must be ruled out, including dehydration, medications, prolonged bed rest, anemia, hyperthyroidism, and anxiety disorders 1. The pathophysiology of POTS involves autonomic nervous system dysfunction, with several proposed mechanisms including partial dysautonomia, hypovolemia, hyperadrenergic states, and autoimmune factors. Diagnostic testing typically includes:
• A detailed medical history
• Orthostatic vital sign measurements
• Sometimes specialized autonomic testing like the tilt table test
• Blood tests, ECG, echocardiogram, or 24-hour Holter monitoring to exclude other conditions 1. It is essential to note that POTS is frequently associated with deconditioning, recent infections, chronic fatigue syndrome, joint hypermobility syndrome, and a spectrum of non-specific symptoms such as headache and chest pain 1.

From the Research

Diagnostic Criteria for Postural Orthostatic Tachycardia Syndrome (POTS)

The diagnostic criteria for POTS include:

• An increase in heart rate of at least 30 beats per minute within 10 minutes of standing, without orthostatic hypotension 2, 3, 4
• Symptoms of orthostatic intolerance, such as palpitations, chest discomfort, shortness of breath, weakness, exercise intolerance, lightheadedness, presyncope, and syncope 2, 3, 5
• Absence of other medical conditions or medications that could cause the symptoms 3

Diagnostic Tests for POTS

Diagnostic tests for POTS may include:

• Tilt-table test 2, 3
• Standing test 2
• Serum norepinephrine levels 2
• Red-cell volumes 2
• Resting 12-lead electrocardiogram 3
• Orthostatic vital signs 3

Pathophysiological Mechanisms of POTS

The pathophysiological mechanisms of POTS are complex and multifactorial, and may include:

• Partial autonomic neuropathy 4
• Hypovolemia 4
• Hyperadrenergic state 4
• Autoimmunity 5
• Sympathetic denervation leading to central hypovolemia and reflex tachycardia 5

Importance of Accurate Diagnosis

Accurate diagnosis of POTS is crucial in providing appropriate treatment and improving patients' functional capability and quality of life 2, 3