title: Transient cerebral hypoperfusion and hypertensive events during atrial fibrillation: a plausible mechanism for cognitive impairment.
abstract: Atrial fibrillation (AF) is associated with an increased risk of dementia and cognitive decline, independent of strokes. Several mechanisms have been proposed to explain this association, but altered cerebral blood flow dynamics during AF has been poorly investigated: in particular, it is unknown how AF influences hemodynamic parameters of the distal cerebral circulation, at the arteriolar and capillary level. Two coupled lumped-parameter models (systemic and cerebrovascular circulations, respectively) were here used to simulate sinus rhythm (SR) and AF. For each simulation 5000 cardiac cycles were analyzed and cerebral hemodynamic parameters were calculated. With respect to SR, AF triggered a higher variability of the cerebral hemodynamic variables which increases proceeding towards the distal circulation, reaching the maximum extent at the arteriolar and capillary levels. This variability led to critical cerebral hemodynamic events of excessive pressure or reduced blood flow: 303 hypoperfusions occurred at the arteriolar level, while 387 hypertensive events occurred at the capillary level during AF. By contrast, neither hypoperfusions nor hypertensive events occurred during SR. Thus, the impact of AF per se on cerebral hemodynamics candidates as a relevant mechanism into the genesis of AF-related cognitive impairment/dementia.
authors.affiliation: Division of Cardiology, Department of Medical Sciences, "Città della Salute e della Scienza" Hospital, University of Turin, Torino, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Anselmino
authors.affiliation: Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Scarsoglio
authors.affiliation: Division of Cardiology, Department of Medical Sciences, "Città della Salute e della Scienza" Hospital, University of Turin, Torino, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Saglietto
authors.affiliation: Division of Cardiology, Department of Medical Sciences, "Città della Salute e della Scienza" Hospital, University of Turin, Torino, Italy.
authors.forename: Fiorenzo
authors.initials: F
authors.lastname: Gaita
authors.affiliation: Department of Environmental, Land and Infrastructure Engineering, Politecnico di Torino, Torino, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Ridolfi
mesh_terms: D001281:Atrial Fibrillation / Q000150:complications / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D060825:Cognitive Dysfunction / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008955:Models, Cardiovascular; D008959:Models, Neurological