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

From the Guidelines

Postural Orthostatic Tachycardia Syndrome (POTS) is diagnosed through a combination of clinical evaluation and specific testing, with the primary diagnostic criterion being an increase in heart rate of at least 30 beats per minute (or ≥40 bpm in those aged 12-19) within 10 minutes of standing or during a tilt table test, without orthostatic hypotension, as defined by the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1.

Diagnostic Criteria

The diagnosis of POTS typically requires symptoms to persist for at least 3 months. The key diagnostic features 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 y of age)
• The absence of orthostatic hypotension (>20 mm Hg reduction in systolic BP)

Diagnostic Tests

Useful tests for diagnosing POTS include:

• Tilt table test: the gold standard diagnostic tool, where patients are secured to a table that tilts from horizontal to vertical while heart rate and blood pressure are monitored
• Standing test (active stand test): where heart rate and blood pressure are measured after the patient moves from lying to standing
• 24-hour Holter monitor: to detect heart rate abnormalities
• Blood tests: to rule out other conditions like anemia or thyroid disorders

Importance of Accurate Diagnosis

It's essential to note that POTS is often misdiagnosed as anxiety or deconditioning, so persistence in seeking proper evaluation from a cardiologist or neurologist with experience in autonomic disorders is crucial for accurate diagnosis, as stated in the guidelines 1. Patients should keep a symptom diary noting triggers and severity of episodes to aid diagnosis.

From the Research

POTS Diagnosis Criteria

• POTS is characterized by an increased heart rate (ΔHR) of ≥30 bpm with symptoms related to upright posture 2
• The 30 bpm ΔHR criterion is not suitable for 30 min tilt, and diagnosis of POTS should consider orthostatic intolerance criteria and not be based solely on orthostatic tachycardia regardless of test used 2
• Orthostatic tachycardia was greater for tilt than stand at 10 and 30 min, with lower specificity for POTS diagnosis 2

Diagnostic Testing

• Head-up tilt table testing can be used to diagnose POTS, with a heart rate increase of > or = 30 beats/min (or a maximum heart rate of 120 beats/min) within the first 10 minutes upright 3
• Active stand and passive head-up tilt produce different physiological responses, which can affect the ability of individuals to achieve the POTS HR increase criterion 2

Clinical Presentation

• Patients with POTS report symptoms such as dizziness, lightheadedness, weakness, blurred vision, and fatigue upon standing 4
• POTS can be mistaken for panic disorder, inappropriate sinus tachycardia, and chronic fatigue syndrome, and clinician suspicion for the syndrome is key to prompt patient diagnosis and treatment 5

Diagnosis and Treatment

• Diagnosis of POTS is made when an orthostatic intolerance and tachycardia appear in the standing position 4
• Treatment approaches for POTS are varied and depend on the underlying phenotype, with first-line treatment focusing on lifestyle modifications such as increased fluid and salt intake, compression garment use, physical reconditioning, and postural training 6