Makindo Medical Notes

Postural orthostatic tachycardia syndrome (POTS) is the final common pathway of a heterogeneous group of underlying disorders that display similar clinical characteristics

Earth bound astronaut
Autonomic system shot
One can barely stand
Slow tilt, near faint, cold sweaty
Racing against gravity
@DrCindyCooper

About

• POTS is a heterogeneous group of disorders resulting in a common clinical scenario.

Aetiology: unclear cause

• Neuroendocrine dysfunction
• Small fiber neuropathy
• MAST cell activation
• Seen to have high plasma norepinephrine levels

Definition: Diagnostic criteria

• Heart rate increases +30 bpm from supine to standing (10 min)
• Symptoms worsen with standing and improved with recumbence
• Symptoms last > 6 mo
• Absence of other overt cause of orthostatic symptoms or tachycardia (eg, active bleeding, acute dehydration, medications)

Clinical

• Female > Male 5:1
• Onset after viral illness, COVID, pregnancy, immunization, sepsis, surgery, trauma.
• Orthostatic intolerance, palpitations, fatigue
• Frequent episodes of light headedness and near syncope.
• Exercise intolerance and dyspnoea on exertion
• Exacerbation of symptoms around menstruation
• Fatigue, unrefreshing sleep, and daytime sleepiness.
• Irritable bowel syndrome, hypermobile joints, abnormal sudomotor regulation.
• 50% have a dependent acrocyanosis seen below in the person on the right. There is a dark red-blue discoloration of their legs (feet to above knees), which are cold to the touch.

Dependent acrocyanosis

Investigations

• FBC, U&E, LFTs, CRP - normal
• ECG - resting normal
• Echo - normal
• 24 hr tape - episodes of tachycardia
• Positive tilt table

Management

• Stopping drugs that could contribute: antidepressants, Antihypertensive, Ethanol, Opiates, Sildenafil citrate. Volume replacement and Vasoconstrictors. Management is largely trial and error to make quality of life optimal.
• Reconditioning: Aerobic exercise 20 min 3 times / week. If too vigorous may worsen symptoms. Some unable to exercise due to fatigue etc.
• Intravenous saline (immediate effect) 1 L over 1–2 h IV; short-term emergency treatment
• Panty hose–style compression stockings: 30–40 mm Hg counterpressure
• Hydration: 2 liters PO/day could cause oedema
• Salt added 2-4 grams/day can cause oedema
• Fludrocortisone 0.1-0.2 mg PO daily. May cause Hypokalemia, hypomagnesemia, edema
• Desmopressin (DDAVP):0.2 mg orally 1 time for occasional use. Could cause hyponatremia with regular use
• Midodrine: 5-10 mg PO TID. May cause Nausea, scalp pruritus, supine hypertension
• Metoprolol: may be beneficial in adolescent type POTS patients
• Erythropoietin: Severely affected and refractory patients. EPO increases red cell mass, central blood volume and augments response of blood vessels to the angiotensin-II and thus causes vasoconstriction.
• There are many other medications trialed. See references below

References

• Postural Orthostatic Tachycardia Syndrome (POTS): Evaluation and Management
• POTS Review from the AHA