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 exceeding 120 beats per minute) within 10 minutes of standing upright, without a corresponding drop in blood pressure, 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 is based on the following criteria:
- 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) 1
- The absence of orthostatic hypotension (>20 mm Hg reduction in systolic BP) 1
- Symptoms that occur with standing, such as lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, exercise intolerance, and fatigue 1
Diagnostic Testing
Diagnostic testing for POTS typically includes:
- A standing test or tilt table test to assess heart rate and blood pressure changes while changing from a lying to standing position 1
- Blood tests, ECG, echocardiogram, or other relevant tests to rule out other conditions that could cause similar symptoms 1
Importance of Proper Diagnosis
Proper diagnosis of POTS is crucial as it guides appropriate treatment strategies, including:
- Increased fluid and salt intake
- Compression garments
- Exercise programs
- Medications like fludrocortisone, midodrine, or beta-blockers in some cases 1 It's essential to note that POTS is often misdiagnosed or overlooked because symptoms can mimic anxiety or deconditioning, so patients may need to specifically request orthostatic vital sign testing if they experience positional symptoms 1.
From the Research
Diagnosis of Postural Orthostatic Tachycardia Syndrome (POTS)
To diagnose POTS, the following criteria must be met:
- A sustained heart rate increment of 30 beats/min or more (40 beats/min for teenagers) within 10min of standing or head-up tilt in the absence of orthostatic hypotension 2, 3
- The standing heart rate is often 120 beats/min or higher 2, 3
- Symptoms of cerebral hypoperfusion or sympathetic activation, such as fatigue, exercise intolerance, and gastrointestinal distress 2, 3, 4
Evaluation and Testing
The evaluation of a patient with suspected POTS should include:
- A focused history and examination 3, 4
- Tests to determine the most likely pathophysiologic basis of orthostatic intolerance, such as:
- Autonomic and laboratory tests to exclude conditions that could cause or mimic the syndrome 2, 4
Importance of Comprehensive Evaluation
A comprehensive cardiac and neurologic examination is necessary to determine the underlying pathophysiologic mechanisms of POTS, which can include limited autonomic neuropathy, hyperadrenergic state, hypovolemia, venous pooling, and deconditioning 2, 3, 5. Additionally, common comorbidities such as visceral pain and dysmotility, chronic fatigue and fibromyalgia, migraine, joint hypermobility, mitral valve prolapse, and inappropriate sinus tachycardia should be identified and addressed 2, 3.