5. Subtypes and Variants of POTS

← PREVIOUS: [[4.5. Small fiber neuropathy and nerve dysfunction]] | NEXT: [[5.1. Hyperadrenergic POTS]] → -------- ##### Summary >[!Summary] >POTS has been classified into several subtypes: >1. neuropathic POTS[[#^1]] (partial peripheral sympathetic denervation leading to relative central hypovolemia)[[#^5]] >2. hyperadrenergic POTS[[#^1]] (increased sympathetic nervous system tone)[[#^5]] >3. absolute hypovolemia (low blood volume)[[#^5]] > >Based on measurement of leg venous pressure and calf blood flow:[[#^1]] >1. low-flow POTS[[#^1]] >2. high-flow POTS[[#^1]] >3. normal-flow POTS[[#^1]] >- hyperadrenergic and hypovolemic correlates are likely compensatory or exacerbating[[#^2]] >- ‘hypovolemic’ subtype and peripheral sympathetic denervation are very close to each other, whereas the ‘hyperadrenergic’ subtype and abnormally increased sympathetic activity are two faces of the same condition[[#^3]] >- patterns of clinical features have been used to sub-type patients, but these classifications are mainly descriptive and are not mutually exclusive[[#^4]] -------- >_“Based on autonomic testing and plasma norepinephrine (NE) levels, POTS has been classified into several subtypes, including neuropathic and hyperadrenergic POTS, and, based on measurement of leg venous pressure and calf blood flow, as low-flow, high-flow, and normal-flow POTS.”_ ([[Benarroch-2012]], [p. 2](zotero://open-pdf/library/items/WEZLT9QC?page=2&annotation=3FH2UVJU))^1 >*“Hyperadrenergic and hypovolemic correlates are likely compensatory or exacerbating.” *([[Thieben-2007]], [p. 6](zotero://open-pdf/library/items/5WXWEQWX?page=6&annotation=JX6ZIL8W))^2 >*“One might argue that the ‘hypovolemic’ subtype and peripheral sympathetic denervation are very close to each other, whereas the ‘hyperadrenergic’ subtype and abnormally increased sympathetic activity are two faces of the same condition.” *([[Fedorowski-2019]], [p. 6](zotero://open-pdf/library/items/BZ35QDLR?page=6&annotation=448IMUIW))^3 >*“Although patterns of clinical features have been used to sub-type patients, these classifications are mainly descriptive and are not mutually exclusive” *([[Garland-2015]], [p. 6](zotero://open-pdf/library/items/CAWTWYLR?page=6&annotation=MMSEAWY3))^4 >*“Features described in subgroups of patients include increased sympathetic nervous system tone (i.e., hyperadrenergic POTS),17 partial peripheral sympathetic denervation leading to relative central hypovolemia (i.e., neuropathic POTS)27 and low blood volume (i.e., absolute hypovolemia),28 which may drive some of the other hemodynamic findings.”* ([[Raj-2022]], [p. 3](zotero://open-pdf/library/items/YN8BG2FZ?page=3&annotation=JZU9T2UM))^5