Postural orthostatic tachycardia syndrome explained using a baroreflex response model

Justen R. Geddes, Johnny T. Ottesen, Jesper Mehlsen, Mette S. Olufsen

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Abstract

Patients with postural orthostatic tachycardia syndrome (POTS) experience an excessive increase in heart rate (HR) and low-frequency (∼0.1 Hz) blood pressure (BP) and HR oscillations upon head-up tilt (HUT). These responses are attributed to increased baroreflex (BR) responses modulating sympathetic and parasympathetic signalling. This study uses a closed-loop cardiovascular compartment model controlled by the BR to predict BP and HR dynamics in response to HUT. The cardiovascular model predicts these quantities in the left ventricle, upper and lower body arteries and veins. HUT is simulated by letting gravity shift blood volume (BV) from the upper to the lower body compartments, and the BR control is modelled using set-point functions modulating peripheral vascular resistance, compliance, and cardiac contractility in response to changes in mean carotid BP. We demonstrate that modulation of parameters characterizing BR sensitivity allows us to predict the persistent increase in HR and the low-frequency BP and HR oscillations observed in POTS patients. Moreover, by increasing BR sensitivity, inhibiting BR control of the lower body vasculature, and decreasing central BV, we demonstrate that it is possible to simulate patients with neuropathic and hyperadrenergic POTS.

OriginalsprogEngelsk
Artikelnummer20220220
TidsskriftJournal of the Royal Society, Interface
Vol/bind19
Udgave nummer193
Sider (fra-til)20220220
Antal sider1
ISSN1742-5689
DOI
StatusUdgivet - 24 aug. 2022

Emneord

  • autonomic dysfunction
  • baroreflex
  • head-up tilt
  • mathematical modelling
  • POTS

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