From the Guidelines
The best course of action to evaluate for Postural Orthostatic Tachycardia Syndrome (POTS) is to perform a standing test, either as a bedside active stand test or a formal tilt table test, as recommended by the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1.
Diagnostic Criteria
The patient should first rest supine for 5-10 minutes, then have heart rate and blood pressure measured while lying down. Next, the patient should stand upright for 10 minutes with heart rate and blood pressure measurements taken at 2,5, and 10 minutes of standing. POTS is diagnosed when there is an increase in heart rate of at least 30 beats per minute (or ≥40 beats per minute in those aged 12-19 years) within 10 minutes of standing, without orthostatic hypotension (a drop in blood pressure >20/10 mmHg), and with symptoms of orthostatic intolerance, as defined in the 2018 ESC guidelines for the diagnosis and management of syncope 1.
Additional Testing
Additional testing may include:
- A 24-hour Holter monitor to rule out arrhythmias
- Blood tests to exclude anemia or thyroid dysfunction
- An echocardiogram to assess cardiac function It's essential to temporarily discontinue medications that might affect heart rate (such as beta-blockers or stimulants) for 48-72 hours before testing, with physician supervision, as noted in the 2017 ACC/AHA/HRS guideline 1. Patients should also be well-hydrated and avoid caffeine for 24 hours prior to evaluation.
Importance of Accurate Diagnosis
This diagnostic approach is crucial because POTS is often misdiagnosed as anxiety or deconditioning, delaying appropriate treatment for this autonomic nervous system disorder, as highlighted in the 2018 ESC guidelines 1.
From the Research
Evaluation of Postural Orthostatic Tachycardia Syndrome (POTS)
To evaluate for POTS, the following steps can be taken:
- A thorough clinical history and examination are essential to identify the mechanism of symptom onset, clinical features, associated clinical conditions or disorders, and factors that may result in symptom exacerbation 2.
- Laboratory testing can help exclude mimics of autonomic dysfunction, recognize conditions that may exacerbate symptoms, and identify conditions that may cause or be associated with autonomic nervous system disease 2.
- Autonomic testing can confirm a POTS diagnosis, exclude other causes of orthostatic intolerance, and characterize POTS into neuropathic and hyperadrenergic subtypes 2.
- Other diagnostic studies, such as epidermal skin punch biopsy, exercise testing, radiographic studies, sleep studies, gastrointestinal motility studies, and urodynamic studies, should be considered when clinically appropriate 2.
Diagnostic Criteria
Although diagnostic criteria have been developed for POTS, no single set of criteria is universally accepted 3. 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 4.
Management
Management of POTS typically begins with patient education and non-pharmacologic treatment options, such as lifestyle modifications, including increased fluid and salt intake, compression garment use, physical reconditioning, and postural training 5, 4. Various medications are often used to address specific symptoms, but there are currently no FDA-approved medications for the treatment of POTS, and evidence for many of the medications used to treat POTS is not robust 5, 4, 6.