Does syncope exclude Postural Orthostatic Tachycardia Syndrome (POTS)?

From the Guidelines

Syncope does not exclude POTS (Postural Orthostatic Tachycardia Syndrome). In fact, syncope or near-syncope can be a symptom of POTS in some patients. POTS is characterized by an abnormal increase in heart rate upon standing (at least 30 beats per minute increase within 10 minutes of standing) without significant blood pressure drop, along with symptoms of orthostatic intolerance lasting at least 3 months. While many POTS patients experience lightheadedness, dizziness, and pre-syncope, only about 30-40% of POTS patients actually faint. The mechanism of syncope in POTS differs from typical vasovagal syncope, as it's related to blood pooling in the lower extremities and inadequate compensatory tachycardia rather than a sudden drop in blood pressure and heart rate.

Key Points to Consider

• POTS is a clinical syndrome characterized by frequent symptoms that occur with standing, such as lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, exercise intolerance, and fatigue 1.
• The diagnosis of POTS is based on a thorough history, physical examination, and eyewitness observation, if available, as well as 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.
• Syncope in POTS is relatively infrequent, and there is little evidence that the syncope is due to POTS 1.
• Treatments that improve symptoms of POTS might decrease the occurrence of syncope, although this is unknown 1.
• If a patient experiences syncope along with symptoms like fatigue, brain fog, exercise intolerance, and tachycardia upon standing, POTS should still be considered as a potential diagnosis, and appropriate testing such as a tilt table test may be warranted to evaluate for this condition.

Recommendations for Clinical Practice

• Consider POTS as a potential diagnosis in patients with syncope and symptoms of orthostatic intolerance, even if the syncope is not typical of POTS 1.
• Perform a thorough history and physical examination to evaluate for POTS and other causes of syncope 1.
• Use a tilt table test to evaluate for POTS and other causes of syncope, if necessary 1.

From the Research

Syncope and POTS

• Syncope, also known as fainting, is a symptom that can occur in various conditions, including postural orthostatic tachycardia syndrome (POTS) 2, 3.
• POTS is a condition characterized by a rapid heart rate and other symptoms that occur upon standing, while syncope is a loss of consciousness due to a lack of blood flow to the brain 4, 5.

Coexistence of Syncope and POTS

• Research suggests that syncope and POTS can coexist in some patients, with studies showing that patients with POTS may also experience syncope 3.
• A study published in 2011 found that 18 patients with POTS also exhibited symptoms of neurocardiogenic syncope, highlighting the complexity of orthostatic intolerance disorders 3.
• The coexistence of syncope and POTS may require a comprehensive treatment approach that addresses both conditions 2, 6.

Diagnosis and Treatment

• The diagnosis of POTS and syncope typically involves a combination of medical history, physical examination, and diagnostic tests such as tilt-table testing 4, 6.
• Treatment for POTS and syncope may involve lifestyle modifications, such as increasing fluid and salt intake, as well as medications to manage symptoms 2, 5.
• In some cases, patients with POTS and syncope may require more advanced treatments, such as permanent pacing or other interventions 6.