Table 1.

Postural orthostatic tachycardia syndrome (POTS)

Diagnostic features/testing	Pathophysiologic mechanisms involved	Symptoms and associated comorbidities	Management principles
Heart rate increase of 30 beats/minute or more for adults and 40 beats/minute or more for individuals 12 to 19 years old, within 10 minutes of standing or head-up tilt in the absence of orthostatic hypotension. Basic diagnostic evaluation includes tests for exclusion of primary cardiac causes (ECG, echocardiogram, Holter monitoring) and head-up tilt test.	Volume dysregulation Hyperadrenergic states/excessive sympathoexcitatory responses Impaired sympathetic vasoconstriction in the lower extremities Physical deconditioning	Orthostatic: light-headedness, dizziness, presyncope, palpitations. Ehlers-Danlos syndrome: hypermobility of the small and large joints, recurrent joint subluxations, scoliosis, velvety soft skin, and early onset chronic pain. Visceral pain and dysmotility: nausea, bloating, diarrhea, constipation, early satiety. Fatigue, general sleep disturbances, and myofascial pain. Neurologic: chronic migraines, orthostatic headaches, and so-called “brain fog”.	Patient education Nonpharmacologic volume expansion with salt and water replacement Pharmacologic therapy (mineralocorticoids, cholinergics, β-blockers) Physical conditioning/physical countermaneuvers