Patterns of Flow in the Left Coronary Artery

Abstract

The purpose of this investigation is to describe our preliminary observations of the overall pattern of flow in a mold of the left coronary artery of a pig. Flow in the coronary mold was visualized by the injection of dye into the sinus of Valsalva. Studies were performed during steady flow at rates of 100, 200, 300, 400, and 500 mL/min. Studies were also performed during pulsatile flow, using a pulse duplicator that simulated the magnitude and phasic pattern of coronary flow at rest and during reactive hyperemia. At conditions that simulated rest, mean coronary flow was adjusted to 121 mL/min of which 24 mL/min (20 percent) was systolic. During simulated reactive hyperemia, mean flow was 440 mL/min. Visualization of flow revealed the absence of disturbances of turbulence during both steady and pulsatile flow in the left anterior descending (LAD) and left circumflex (CIRC) coronary arteries throughout the entire range of flow studied. Prominent spiraling of flow occurred during steady and pulsatile flow. Spiraling of flow was not observed in the LAD at rest during pulsatile flow, but developed during simulated reactive hyperemia. Helical flows were observed in the CIRC both during simulated rest and reactive hyperemia. These observations suggest that helical flows may be characteristic features of flow in the left coronary artery; whereas turbulence may not be a feature of this flow field. Whether the spiraling of flow that we observed related to the spiral distribution of early atheroma reported by others, is undetermined.

CFD analysis of pulsatile blood flow in an atherosclerotic human artery with eccentric plaques

“…For large-diameter vessels, like arteries, blood is a Cassonian fluid (Lorenzini, 2005;Casson, 1959;Ku, 1997;Sabbah et al, 1984;Thurston, 1979). Recently, a modified-more-general Casson equation was formulated (Gonzalez and Moraga, 2005):…”

Fluid Dynamic Analysis in a Human Left Anterior Descending Coronary Artery with Arterial Motion

“…The magnitudes of the Reynolds number and the Womersley parameter in this study are comparable with those employed in the previous studies. 23 Three cases were compared in this study:…”

Plaque development, vessel curvature, and wall shear stress in coronary arteries assessed by X-ray angiography and intravascular ultrasound

“…Further, the no-slip boundary condition is specified at the vessel wall and a constant pressure outlet condition is utilized in the CFD model. The mean flow rate through the left main coronary artery has been reported to be around 100-120 ml/min (Sabbah et al, 1984;Perktold et al, 1998). Since the flow rate could not be measured in each of the coronary arteries during data acquisition for each patient due to procedural limitations, we consequently assumed a flow rate of 100 ml/min for all the coronary arterial segments employed in this analysis.…”