Accession Number : ADA289701

Title :   Flow through a Complaint Stenotic Artery: A Parametric Evaluation.

Descriptive Note : Final rept. Dec 91-Mar 93,

Corporate Author : ARMSTRONG LAB BROOKS AFB TX OCCUPATIONAL AND ENVIRONMENTAL HEALTH DIRECTORATE

Personal Author(s) : Downing, J. M.

PDF Url : ADA289701

Report Date : MAR 1993

Pagination or Media Count : 154

Abstract : Hardening of the arteries from atherosclerosis can produce high grade stenoses which lead to morbid symptoms of heart attack and stroke. Blood flow through the stenosis produces a low pressure zone at the throat which may cause the elastic artery to collapse. A one-dimensional model of collapsible tube flow through a smooth1 compliant stenoses was developed to evaluate the relative effects of several physiologic parameters. These variables included changes in percent stenosis, distal resistance, viscous separation losses, unsteady effects, stiffness variations, and non-linear tube law shapes. The range of variation attempted to bracket the conditions expected for diseased carotid and coronary arteries. The time-dependent equations were solved using MacCormack's method. Collapsed flow was more likely to be achieved with soft stenoses greater than 80% by diameter, low downstream resistances, and high external pressures. Collapsed flow was less likely to occur with stiff stenoses of less than 80% (dia) with a high distal resistance, large viscous losses, and a low external pressure. Pulsatile conditions resulted in situations where flow could alternate between supercritical and subcritical flow during the cycle. The results demonstrate that collapse of high grade stenotic arteries can occur under physiological conditions.

Descriptors :   *ATTACK, *SIGNS AND SYMPTOMS, *FLOW, *HEART, *CORONARY ARTERIES, TEST AND EVALUATION, PARAMETRIC ANALYSIS, TIME DEPENDENCE, MODELS, PARAMETERS, RESISTANCE, ONE DIMENSIONAL, SHAPE, ELASTIC PROPERTIES, DISEASES, LOW PRESSURE, HIGH PRESSURE, COMPUTATIONAL FLUID DYNAMICS, VARIATIONS, NONLINEAR SYSTEMS, PULSES, PHYSIOLOGICAL EFFECTS, SEPARATION, PHYSIOLOGY, EXTERNAL, LOSSES, EQUATIONS, VISCOSITY, HARDENING, COLLAPSE, COLLAPSIBLE STRUCTURES, BLOOD CIRCULATION, ARTERIES, TUBES, CAROTID ARTERIES, ATHEROSCLEROSIS, STENOSIS, THROAT.

Subject Categories : Anatomy and Physiology
      Medicine and Medical Research
      Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE