Keyword search (3,448 papers available)


Energy loss associated with in-vitro modeling of mitral annular calcification.

Author(s): Wiener PC, Darwish A, Friend E, Kadem L, Pressman GS

INTRODUCTION: Study aims were to compare hemodynamics and viscous energy dissipation (VED) in 3D printed mitral valves-one replicating a normal valve and the other a valve with severe mitral annular calcification (MAC). Patients with severe MAC develop tran...

Article GUID: 33591991
Proper Orthogonal Decomposition Analysis of the Flow Downstream of a Dysfunctional Bileaflet Mechanical Aortic Valve.

Author(s): Darwish A, Di Labbio G, Saleh W, Kadem L

PURPOSE: Aortic valve replacement remains the only viable solution for symptomatic patients with severe aortic valve stenosis. Despite their improved design and long history of successful operation, bileaflet mechanical heart valves are still associated wit...

Article GUID: 33469847
Impact of Mitral Regurgitation on the Flow in a Model of a Left Ventricle.

Author(s): Papolla C, Darwish A, Kadem L, Rieu R

PURPOSE: Mitral regurgitation (MR) is the second most common valve disease in industrialized countries. Despite its high prevalence, little is known about its impact on the flow dynamics in the left ventricle (LV). Because of the interdependence between val...

Article GUID: 33000444
Color Doppler Splay: A Clue to the Presence of Significant Mitral Regurgitation.

Author(s): Wiener PC, Friend EJ, Bhargav R, Radhakrishnan K, Kadem L, Pressman GS

J Am Soc Echocardiogr. 2020 Jul 22;: Authors: Wiener PC, Friend EJ, Bhargav R, Radhakrishnan K, Kadem L, Pressman GS

Article GUID: 32712051
Effects of Hemodynamic Conditions and Valve Sizing on Leaflet Bending Stress in Self-Expanding Transcatheter Aortic Valve: An In-vitro Study.

Author(s): Stanová V, Zenses AS, Thollon L, Kadem L, Barragan P, Rieu R, Pibarot P

Artif Organs. 2020 Jan 29;: Authors: Stanová V, Zenses AS, Thollon L, Kadem L, Barragan P, Rieu R, Pibarot P

Article GUID: 31995230
Experimental Investigation of the Effect of Heart Rate On Flow in the Left Ventricle in Health and Disease -- Aortic Valve Regurgitation.

Author(s): Di Labbio G, Ben-Assa E, Kadem L

J Biomech Eng. 2019 Nov 01;: Authors: Di Labbio G, Ben-Assa E, Kadem L

Article GUID: 31701119
Jet collisions and vortex reversal in the human left ventricle.

Author(s): Di Labbio G, Kadem L

J Biomech. 2018 09 10;78:155-160 Authors: Di Labbio G, Kadem L

Article GUID: 30049450
Response to letter to the editor: 'Left ventricular flow in the presence of aortic regurgitation'.

Author(s): Di Labbio G, Kadem L

J Biomech. 2019 Apr 18;87:212-214 Authors: Di Labbio G, Kadem L PMID: 30871721 [PubMed - in process]

Article GUID: 30871721
Experimental investigation of the flow downstream of a dysfunctional bileaflet mechanical aortic valve.

Author(s): Darwish A, Di Labbio G, Saleh W, Smadi O, Kadem L

Artif Organs. 2019 May 08;: Authors: Darwish A, Di Labbio G, Saleh W, Smadi O, Kadem L

Article GUID: 31066923
Title:Experimental Investigation of the Effect of Heart Rate On Flow in the Left Ventricle in Health and Disease -- Aortic Valve Regurgitation.
Authors:Di Labbio G,  Ben-Assa E,  Kadem L
Link:https://www.ncbi.nlm.nih.gov/pubmed/31701119?dopt=Abstract
DOI:10.1115/1.4045400
Category:J Biomech Eng
PMID:31701119
Dept Affiliation: ENCS
1 Department of Mechanical, Industrial & Aerospace Engineering, Concordia University, 1455 Blvd. De Maisonneuve W., Montréal, QC H3G 1M8, Canada.
2 Cardiology Division, Sackler Faculty of Medicine, Tel Aviv Sourasky Medical Center, Tel Aviv 6997801, Israel; Institute for Medical Engineering and Science, Massachusetts Institute of Technology,77 Massachusetts Avenue, Cambridge, MA 02139.

Description:

Experimental Investigation of the Effect of Heart Rate On Flow in the Left Ventricle in Health and Disease -- Aortic Valve Regurgitation.

J Biomech Eng. 2019 Nov 01;:

Authors: Di Labbio G, Ben-Assa E, Kadem L

Abstract

There is much debate in the literature surrounding the effects of heart rate on aortic regurgitation (AR). Despite the contradictory information, it is still widely believed that an increase in heart rate is beneficial due to the disproportionate shortening of the duration of diastole relative to systole, permitting less time for the left ventricle to fill from regurgitation. This in vitro work investigates how a change in heart rate affects the left ventricular fluid dynamics in the absence and presence of acute AR. Considering fluid dynamic factors, an increase in heart rate was observed to have a limited benefit in the case of mild AR and a detrimental effect for more severe AR. With increasing heart rate, mild AR was associated with a decrease in regurgitant volume, a negligible change in regurgitant volume per diastolic second and a limited reduction in the fraction of retained regurgitant inflow. More severe AR was accompanied by an increase in both regurgitant volume and the fraction of retained regurgitant inflow, implying a less effective pumping efficiency and a longer relative residence time of blood in the ventricle. Globally, the left ventricle's capacity to compensate for the increase in energy dissipation associated with an increase in heart rate diminishes considerably with severity, a phenomenon which may be exploited further as a method of noninvasive assessment of the severity of AR. These findings may affect the clinical belief that tachycardia is preferred in acute AR and should be investigated further in the clinical setting.

PMID: 31701119 [PubMed - as supplied by publisher]