Neurovascular coupling and cerebral autoregulation in atrial fibrillation

J Cereb Blood Flow Metab. 2020 Aug;40(8):1647-1657. doi: 10.1177/0271678X19870770. Epub 2019 Aug 19.

Abstract

The risk of cognitive decline and stroke is increased by atrial fibrillation (AF). We sought to determine whether neurovascular coupling and cerebral autoregulation are blunted in people with AF in comparison with age-matched, patients with hypertension and healthy controls. Neurovascular coupling was assessed using five cycles of visual stimulation for 30 s followed by 30 s with both eyes-closed. Cerebral autoregulation was examined using a sit-stand test, and a repeated squat-to-stand (0.1 Hz) manoeuvre with transfer function analysis of mean arterial pressure (MAP; input) and middle cerebral artery mean blood flow velocity (MCA Vm; output) relationships at 0.1 Hz. Visual stimulation increased posterior cerebral artery conductance, but the magnitude of the response was blunted in patients with AF (18 [8] %; mean [SD]) and hypertension (17 [8] %), in comparison with healthy controls (26 [9] %) (P < 0.05). In contrast, transmission of MAP to MCA Vm was greater in AF patients compared to hypertension and healthy controls, indicating diminished cerebral autoregulation. We have shown for the first time that AF patients have impaired neurovascular coupling responses to visual stimulation and diminished cerebral autoregulation. Such deficits in cerebrovascular regulation may contribute to the increased risk of cerebral dysfunction in people with AF.

Keywords: Aging; atrial fibrillation; brain; cerebral circulation; hypertension.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aging / physiology
  • Atrial Fibrillation / physiopathology*
  • Blood Flow Velocity / physiology*
  • Brain / blood supply*
  • Case-Control Studies
  • Cerebrovascular Circulation / physiology*
  • Cross-Sectional Studies
  • Female
  • Homeostasis / physiology*
  • Humans
  • Hypertension / physiopathology
  • Male
  • Middle Cerebral Artery / physiology
  • Neurovascular Coupling / physiology*
  • Photic Stimulation
  • Posterior Cerebral Artery / physiology