The Basic Physiology of Orthostatic Tachycardia

Orthostatic POTS is characterized by an exaggerated sympathetic nervous system tone, with elevated standing plasma norepinephrine levels. Trauma infection, pregnancy, and surgery have all been reported as triggers to the onset of POTS. Some patients have persistently low plasma volumes which have been postulated to be secondary to impaired function of the renin angiotensin-eldosterone system.