What is the workup for Postural Orthostatic Tachycardia Syndrome (POTS) and which specialist usually performs it?

Workup for Postural Orthostatic Tachycardia Syndrome (POTS)

The workup for POTS should be performed by a specialist trained in autonomic function testing and interpretation, typically a cardiologist or neurologist with expertise in autonomic disorders. 1, 2

Diagnostic Criteria

POTS is diagnosed based on the following criteria:

• Sustained heart rate increase ≥30 bpm within 10 minutes of standing (≥40 bpm for individuals aged 12-19 years)
• Absence of orthostatic hypotension (no drop >20 mmHg in systolic BP)
• Frequent symptoms of orthostatic intolerance during standing
• Symptoms improve rapidly when returning to supine position
• Duration of symptoms for at least 3 months
• Absence of other conditions explaining sinus tachycardia 2

Comprehensive Workup Protocol

1. Orthostatic Testing

• Active Standing Test: Measure blood pressure and heart rate after 5 minutes lying supine, then immediately upon standing and at 2,5, and 10 minutes thereafter 2
• Head-up Tilt Table Test: The gold standard test performed in a dedicated laboratory with beat-to-beat BP and ECG monitoring, using a motorized tilt table 1, 3

2. Laboratory Testing

• Complete blood count
• Basic metabolic panel
• Thyroid function tests
• Cardiac biomarkers (troponin)
• C-reactive protein 2

3. Cardiac Evaluation

• 12-lead ECG
• Echocardiogram
• 24-48 hour Holter monitor or longer ambulatory rhythm monitoring 2

4. Autonomic Function Tests

• Valsalva Maneuver: Patient performs forced expiration for 15 seconds against resistance while monitoring hemodynamic changes 1
• Autonomic function assessment: Performed to characterize cardiovascular sympathetic and parasympathetic function 1

5. Additional Testing

• 6-minute walk test to assess functional capacity
• Chest imaging (X-ray and/or CT)
• Pulmonary function tests 2

Specialist Involvement

The workup for POTS is typically performed by:

1. Cardiologists with expertise in autonomic disorders - these specialists most commonly lead the diagnostic process 2
2. Neurologists with expertise in autonomic nervous system disorders 2
3. Electrophysiologists who specialize in heart rhythm disorders

Important Considerations During Workup

• Testing should ideally be performed before noon in a quiet environment
• Room should be temperature controlled (21-23°C)
• Patients should be fasted for 3 hours before testing
• Patients should avoid nicotine, caffeine, theine, or taurine-containing drinks on the day of examination 1
• The workup should exclude other conditions that could cause or mimic POTS 4

Common Pitfalls to Avoid

• Failure to perform formal standing tests to document objective evidence of postural tachycardia
• Confusing POTS with other causes of orthostatic symptoms
• Overlooking associated conditions
• Focusing solely on heart rate control without addressing underlying pathophysiology 2

Phenotype Identification

During workup, it's important to identify the specific POTS phenotype to guide treatment:

• Hyperadrenergic: Characterized by excessive norepinephrine production
• Neuropathic: Results from impaired vasoconstriction during orthostatic stress
• Hypovolemic: Often triggered by dehydration and physical deconditioning 5, 6

Regular follow-up with a cardiologist or neurologist experienced in managing POTS is essential after diagnosis to monitor symptoms and adjust treatment as needed 2.