Individuals with Postural Orthostatic Tachycardia Syndrome (POTS) suffer from an excessive increase in heart rate (tachycardia) and other symptoms of dysautonomia that worsen upon standing or sitting up, such as light-headedness, shortness of breath, chest pain, and palpitations. These symptoms are disabling for many individuals, with impairments seen in quality of life and multiple domains of physical and social functioning. While disordered autonomic responses (dysautonomia) in POTS are well recognized, the underlying mechanisms driving this response are complex, and there is a need to better characterize the different subtypes of POTS in order to accelerate new diagnostic and therapeutic modalities for this disorder. Many individuals experiencing POTS have reduced intravascular volume which contributes to orthostatic intolerance via mechanisms similar to those seen in deconditioning. Some individuals with POTS also demonstrate evidence of increased cardiovascular adrenergic function suggesting an underlying hyperadrenergic state, additionally small fiber neuropathy and autoimmune factors may also play a role in development of the syndrome.
Epidemiologic studies show that POTS affects women more commonly than men (5:1 predominance of females to males) but the exact prevalence of POTS is unknown. In addition to sex, age, genetic, environmental and other factors influence susceptibility to POTS. Many people with POTS report a preceding medical or life-changing event such as viral infection, concussion, surgery or pregnancy and up to half of individuals report symptoms beginning during adolescence. Recent reports of increased incidence of POTS-like symptoms during the COVID-19 pandemic have further highlighted the possibility of a connection of this syndrome with viral infections, and increases the urgency for robust research to better understand the etiology and mechanisms by which POTS develops.
POTS currently has no curative or standardized therapy and current interventions focus on addressing symptoms rather than underlying pathologic drivers. Some individuals with POTS benefit acutely from dietary salt and volume expansion, however there are limited data on the long-term effects of such therapy. Drug therapies focused on increasing blood pressure, expanding blood volume, and lowering heart rate can also be helpful. Exercise training, with a primary focus on aerobic reconditioning, has also been shown to benefit symptoms.