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:Effects of Hemodynamic Conditions and Valve Sizing on Leaflet Bending Stress in Self-Expanding Transcatheter Aortic Valve: An In-vitro Study.
Authors:Stanová V,  Zenses AS,  Thollon L,  Kadem L,  Barragan P,  Rieu R,  Pibarot P
Link:https://www.ncbi.nlm.nih.gov/pubmed/31995230?dopt=Abstract
DOI:10.1111/aor.13654
Category:Artif Organs
PMID:31995230
Dept Affiliation: ENCS
1 Aix Marseille Univ, IFSTTAR, LBA, Marseille, France.
2 Quebec Heart and Lung Institute, Laval University, Quebec, QC, Canada.
3 Department of Mechanical Industrial and Aerospace Engineering, Concordia University, Montreal, QC, Canada.
4 Cardiologie interventionnelle, Clinique des Fleurs, Ollioules, France.

Description:

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

Artif Organs. 2020 Jan 29;:

Authors: Stanová V, Zenses AS, Thollon L, Kadem L, Barragan P, Rieu R, Pibarot P

Abstract

OBJECTIVES: Transcatheter aortic valve (TAV) replacement has become a viable alternative to surgery for high and intermediate risk patients with severe aortic stenosis. This technology may extend to the younger and lower risk patients. In this population, long-term durability of the TAV is key. Increased leaflet mechanical stress is one of the main determinants of valve structural deterioration. This in vitro study aims at evaluating, leaflet bending stress (LBS) in the self-expanding TAV for different valve sizes, stroke volumes (SV) and degrees of valve oversizing (OS).

METHODS: Three different sizes (23, 26, 29 mm) of CoreValve (CV) were tested on a pulse duplicator in annulus size ranging from 17 to 26 mm. Leaflet bending stress and bending of the leaflet coaptation line in diastole (pin-wheeling index) were measured using high-speed camera imaging (1000 images/sec).

RESULTS: For each given CV and annulus size, geometric orifice area increased significantly with OS (p<0.001) and SV (p=0.001). LBS decreased with increasing prosthesis size and aortic annulus (AA) size while increasing with SV(p<0.03). The largest value of peak LBS (3.79 MPa) was obtained with the CV 23 mm in AA of 17 mm (%OS=35%), SV 90 ml and the smallest value (0.99 MPa) for the CV 29 mm in AA of 26 mm (%OS=12%), SV 30 ml. On multivariable analysis, LBS increased independently with larger OS, smaller AA size and higher SV. The pin-wheeling index increased with decreasing AA size and increasing OS.

CONCLUSIONS: Moderate valve OS, such as generally used for transcatheter aortic valve implantation, is associated with increased LBS during valve opening and closing, especially in small annuli. Hence, TAV OS may negatively impact long-term valve durability.

PMID: 31995230 [PubMed - as supplied by publisher]