Postural tachycardia syndrome (POTS)

Postural tachycardia syndrome (POTS) is a syndrome of orthostatic tachycardia associated with symptoms of cerebral hypoperfusion and/or autonomic activation. Prevalence is higher in females between the ages of 20 and 50 years. This chapter will focus on phenotypes of POTS and an introduction to management. Chapter 107 will focus specifically on mechanisms of POTS. Some patients have a limited autonomic neuropathy. An antecedent event such as a viral infection occurs in approximately half the patients. Evidence of peripheral denervation of sudomotor fibers includes sweat loss of the legs on thermoregulatory sweat test or QSART. Peripheral adrenergic denervation can be present, resulting in impairment of reflex vasoconstriction with baroreflex unloading. In hyperadrenergic POTS, sympathetic tone is increased, manifest as orthostatic hyperadrenergic response, and sometimes as spontaneous episode of excessive sympathetic activity. POTS is usually associated with deconditioning and in POTS with deconditioning, this can be the dominant feature. The linchpins of management of POTS comprise volume expansion, education, and conditioning exercise. Medications such as beta-adrenoreceptor blockers, midodrine, and pyridostigmine have a limited role in management.