What is the workup for Postural Orthostatic Tachycardia Syndrome (POTS)?

From the Guidelines

A comprehensive POTS workup should begin with orthostatic vital signs, measuring heart rate and blood pressure while lying down and then after standing for 2-10 minutes, as recommended by the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1. The diagnosis of POTS is based on an increase in heart rate of at least 30 beats per minute (40 bpm for those 12-19 years old) without orthostatic hypotension. Additional testing should include:

• A complete blood count, comprehensive metabolic panel, thyroid function tests, and morning cortisol to rule out other causes.
• A 12-lead ECG and 24-hour Holter monitor can help exclude arrhythmias.
• In some cases, a tilt table test may be necessary to confirm the diagnosis by reproducing symptoms under controlled conditions.
• Autonomic testing might include quantitative sudomotor axon reflex testing (QSART) and heart rate variability assessment.
• Hyperadrenergic POTS may require catecholamine levels measured while supine and standing. Patients should be evaluated for underlying conditions like Ehlers-Danlos syndrome, autoimmune disorders, or recent viral infections that can trigger POTS, as suggested by the 2018 ESC guidelines for the diagnosis and management of syncope 1. This comprehensive approach helps establish the diagnosis and identify any contributing factors that may guide treatment, as supported by the 2022 ACC expert consensus decision pathway on cardiovascular sequelae of COVID-19 in adults 1.

Some key points to consider in the workup and management of POTS include:

• The importance of a thorough history and physical examination to identify underlying conditions that may be contributing to POTS.
• The use of non-pharmacological interventions such as salt and fluid loading, elevation of the head of the bed, and support stockings to address plasma volume reduction and orthostatic intolerance.
• The potential use of pharmacological therapies such as beta-blockers, calcium-channel blockers, and ivabradine to manage symptoms and improve quality of life.
• The need for careful monitoring and follow-up to adjust treatment and address any complications that may arise.

From the Research

POTS Workup

The workup for Postural Orthostatic Tachycardia Syndrome (POTS) involves a comprehensive approach to establish the diagnosis, identify co-morbid conditions, and exclude other conditions that could cause or mimic the syndrome 2. The evaluation requires:

• A focused history and examination to identify the mechanism of symptom onset, clinical features, and associated conditions 3, 4
• Laboratory testing to 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 4
• Autonomic testing to confirm the diagnosis, exclude other causes of orthostatic intolerance, and characterize POTS into neuropathic and hyperadrenergic subtypes 3, 4
• Other diagnostic studies, such as epidermal skin punch biopsy, exercise testing, radiographic studies, sleep studies, gastrointestinal motility studies, and urodynamic studies, may be considered when clinically appropriate 4

Diagnostic Criteria

Although diagnostic criteria have been developed for POTS, no single set of criteria is universally accepted 5. The diagnosis is typically based on the presence of orthostatic symptoms associated with a heart rate increment of at least 30 beats per minute upon assuming an upright position, without orthostatic hypotension 6, 3.

Pathophysiologic Mechanisms

POTS is a heterogeneous disorder with multiple contributing pathophysiologic mechanisms, including:

• Partial autonomic neuropathy 6, 3
• Hypovolemia 6, 3
• Hyperadrenergic state 6, 3
• Venous pooling 3
• Beta-receptor supersensitivity 3
• Psychologic mechanisms 3
• Presumed impairment of brain stem regulation 3

Management

The management of POTS typically begins with patient education and non-pharmacologic treatment options, such as a high salt diet, copious fluids, and postural training 3, 2. Various medications may be 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 2.