Computational fluid dynamics of left ventricular ejection

John G Georgiadis, Mingyu Wang, Ares Pasipoularides

Research output: Contribution to journalArticle

Abstract

The present investigation addresses the effects of simple geometric variations on intraventricular ejection dynamics, by methods from computational fluid dynamics. It is an early step in incorporating more and more relevant characteristics of the ejection process, such as a continuously changing irregular geometry, in numerical simulations. We consider the effects of varying chamber eccentricities and outflow valve orifice-to-inner surface area ratios on instantaneous ejection gradients along the axis of symmetry of the left ventricle. The equation of motion for the streamfunction was discretized and solved iteratively with specified boundary conditions on a boundary-fitted adaptive grid, using an alternating-direction-implicit (ADI) algorithm. The unsteady aspects of the ejection process were subsequently introduced into the numerical simulation. It was shown that for given chamber volume and outflow orifice area, higher chamber eccentricities require higher ejection pressure gradients for the same velocity and local acceleration values at the aortic anulus than more spherical shapes. This finding is referable to the rise in local acceleration effects across the outflow axis. This is to be contrasted with the case of outflow orifice stenosis, in which it was shown that it is the convective acceleration effects that are intensified strongly.

Original languageEnglish (US)
Pages (from-to)81-97
Number of pages17
JournalAnnals of Biomedical Engineering
Volume20
Issue number1
DOIs
StatePublished - Jan 1 1992

Keywords

  • Alternating direction implicit algorithm
  • Boundary fitted adaptive grid
  • Cardiac fluid dynamics
  • Computational fluid dynamics
  • Intracardiac ejection flow
  • Intraventricular pressure gradients
  • Unsteady flow

ASJC Scopus subject areas

  • Biomedical Engineering

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