title: The dicrotic notch analyzed by a numerical model.
abstract: Divergent concepts on the origin of the dicrotic notch are widespread in medical literature and education. Since most medical textbooks explain the origin of the dicrotic notch as caused by the aortic valve closure itself, this is commonly transmitted in medical physiology courses. We present clinical data and numerical simulations to demonstrate that reflected pressure waves could participate as one of the causes of the dicrotic notch. Our experimental data from continuous arterial pressure measurements from adult patients undergoing vascular surgery suggest that isolated changes in peripheral vascular resistance using an intravenous bolus of phenylephrine (a selective alpha 1-receptor agonist and thus a potent vasoconstrictor) modify the dicrotic notch. We then explore the mechanisms behind this phenomenon by using a numerical model based on integrated axisymmetric Navier-Stokes equations to compute the hemodynamic flow. Our model illustrates clearly how modifications in peripheral artery resistance may result in changes in the amplitude of the dicrotic notch by modifying reflected pressure waves. We believe that this could be a useful tool in teaching medical physiology courses.
authors.affiliation: Laboratorio de Biomembranas. Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay). Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, C1121ABG Buenos Aires, Argentina. Electronic address: teresapoliti@yahoo.com.ar.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Politi
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7190, Institut Jean Le Rond d'Alembert, F-75005 Paris, France. Electronic address: arthur.ghigo@dalembert.upmc.fr.
authors.forename: Arthur
authors.initials: A
authors.lastname: Ghigo
authors.affiliation: Laboratorio de Biomembranas. Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay). Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, C1121ABG Buenos Aires, Argentina.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Fernández
authors.affiliation: Service de Chirurgie Vasculaire, Hôpitaux Universitaires La Pitié-Salpêtrière, 47-83 Bd de l'Hôpital, 75013 Paris, France.
authors.forename: Ismaïl
authors.initials: I
authors.lastname: Khelifa
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7190, Institut Jean Le Rond d'Alembert, F-75005 Paris, France; Service de Chirurgie Vasculaire, Hôpitaux Universitaires La Pitié-Salpêtrière, 47-83 Bd de l'Hôpital, 75013 Paris, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Gaudric
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7190, Institut Jean Le Rond d'Alembert, F-75005 Paris, France.
authors.forename: José María
authors.initials: JM
authors.lastname: Fullana
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7190, Institut Jean Le Rond d'Alembert, F-75005 Paris, France.
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Lagrée
mesh_terms: D000328:Adult; D001794:Blood Pressure; D006801:Humans; D008962:Models, Theoretical
keywords: Dicrotic notch; Medical physiology; Numerical model; Reflection wave