title: A Computational Study on the Relation between Resting Heart Rate and Atrial Fibrillation Hemodynamics under Exercise.
abstract: OBJECTIVE
  Clinical data indicating a heart rate (HR) target during rate control therapy for permanent atrial fibrillation (AF) and assessing its eventual relationship with reduced exercise tolerance are lacking. The present study aims at investigating the impact of resting HR on the hemodynamic response to exercise in permanent AF patients by means of a computational cardiovascular model.
  
  
  METHODS
  The AF lumped-parameter model was run to simulate resting (1 Metabolic Equivalent of Task-MET) and various exercise conditions (4 METs: brisk walking; 6 METs: skiing; 8 METs: running), considering different resting HR (70 bpm for the slower resting HR-SHR-simulations, and 100 bpm for the higher resting HR-HHR-simulations). To compare relative variations of cardiovascular variables upon exertion, the variation comparative index (VCI)-the absolute variation between the exercise and the resting values in SHR simulations referred to the absolute variation in HHR simulations-was calculated at each exercise grade (VCI4, VCI6 and VCI8).
  
  
  RESULTS
  Pulmonary venous pressure underwent a greater increase in HHR compared to SHR simulations (VCI4 = 0.71, VCI6 = 0.73 and VCI8 = 0.77), while for systemic arterial pressure the opposite is true (VCI4 = 1.15, VCI6 = 1.36, VCI8 = 1.56).
  
  
  CONCLUSIONS
  The computational findings suggest that a slower, with respect to a higher resting HR, might be preferable in permanent AF patients, since during exercise pulmonary venous pressure undergoes a slighter increase and systemic blood pressure reveals a more appropriate increase.
authors.affiliation: Division of Cardiology, Department of Medical Sciences, "Città della Salute e della Scienza" Hospital, University of Turin, Turin, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Anselmino
authors.affiliation: DIMEAS -Department of Mechanical and Aerospace Engineering-, Politecnico di Torino, Turin, 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, Turin, Italy.
authors.forename: Andrea
authors.identifier: http://orcid.org/0000-0001-9475-1507
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, Turin, Italy.
authors.forename: Fiorenzo
authors.initials: F
authors.lastname: Gaita
authors.affiliation: DIATI -Department of Environmental, Land and Infrastructure Engineering-, Politecnico di Torino, Turin, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Ridolfi
mesh_terms: D062186:Arterial Pressure; D001281:Atrial Fibrillation / Q000503:physiopathology*; D019295:Computational Biology; D003198:Computer Simulation; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008962:Models, Theoretical; D012146:Rest / Q000502:physiology*; D012420:Running / Q000502:physiology; D012865:Skiing / Q000502:physiology; D016138:Walking / Q000502:physiology