Postural tachycardia syndrome (POTS) is a rare functional cardiovascular disorder characterized by excessive heart rate increase and discomfort during orthostasis, usually accompanied by a spectrum of non–specific symptoms such as sporadic syncope, orthostatic intolerance, deconditioning, headache, cognitive impairment, and gastrointestinal dysfunction. The syndrome affects predominantly young women (70–80%) within a range of 15–40 years, first being defined in 1990s as a variant of orthostatic intolerance and dysautonomic syncope, and its etiology remains largely unknown.
POTS is considered to be one of the most common autonomic disorders affecting the cardiovascular system, with an estimated prevalence of 0.5 million in United States of America (USA) alone. The onset of POTS may follow an acute infection or vaccination but more commonly appears without antecedent causative events. In Sweden, POTS has recently gained more attention during a vivid debate on health consequences of national vaccination program against papilloma virus in younger women. As POTS may lead to debilitating symptoms and uncertain long–term prognosis, a number of treatment options have been proposed but their efficacy in the more severe forms is limited and often questioned.
The role of molecular biomarkers in the diagnosis of POTS is still debatable. Several plasma proteins, including immunoglobulins, as well as other signal substances and neurohormones have been studied for their diagnostic utility in POTS but no conclusive evidence has been presented so far.
Consequently, more studies on the association between POTS, markers of cardiovascular dysautonomia and inflammation are needed, especially in regard to potential mechanisms linking POTS with different manifestations of the syndrome, which keeps vexing the medical community and the affected patients.