Title

Central ejection region (CER) coefficient for the evaluation of left ventricular function

Document Type

Conference Proceeding

Publication Date

12-1-1993

Department

Mechanical Engineering, 2-D Navier-Stokes equation, heart valves

Abstract

Left ventricular (LV) chamber flow is undoubtedly influenced by the time dependent regional motion of the LV wall. In an attempt to obtain diagnostic parameters based on LV chamber flow, we computed the LV chamber 2-D systolic velocity distribution for two right anterior oblique (RAO) ventriculograms; one normal, one with ischemic coronary artery disease, and several simulations with prescribed abnormal wall motion. The flow fields are obtained by solving the discretized 2-D Navier-Stokes equations for viscous, incompressible unsteady flow using the finite analytic method. These solutions were used as a basis for an LV assessment parameter; the central ejection region (CER), defined as the region of flow domain in which the obtained velocity field vectors are aligned ±5 degrees from the LV long axis. A CER coefficient C derived from the location and orientation of the GER within the LV cavity is defined. The time averaged CER coefficient was 0.709 for the normal heart and 0.543 for the deceased heart. The CER shifted toward the region of LV wall which exhibits the abnormal motion, and the CER coefficient decreased with increasing severity of abnormal wall motion. The CER coefficient provides a qualitative and quantitative measure of global function that regional wall motion analysis cannot provide, and is a parameter which is sensitive to regional and temporal abnormalities and the resulting compensatory actions which cannot be detected by global parameters. CER

First Page

439

Last Page

442

Publication Title

American Society of Mechanical Engineers, Bioengineering Division (Publication) BED

ISBN

0791810313

Comments

At the time of publication, Richard T. Schoephoerster was affiliated with Florida International University.

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