3-DIMENSIONAL ANALYSIS OF LEFT-VENTRICULAR EJECTION USING COMPUTATIONAL FLUID-DYNAMICS

We present in this study a method for constructing computational fluid mechanical models in order to study the effects of time-varying left ventricular ejection. A spherical left ventricular model was implement ed in which three dimensional flow fields were obtained. The time cour se of the ventricular wall changes were assumed to have a trigonometri cally varying nature. The wall grid was reformed 25 times during the c alculation since the left ventricular wall motion was assumed to follo w the bloodflow, and the ventricle wall radius was reduced by 60 perce nt in 0.25 seconds. Centerline and cross-sectional velocity vectors gr eatly increased in magnitude at the aortic outlet, and pressure droppe d from 1.17x10(4) dynes/cm(2) (8.8 mmHg) to zero in the top 10 percent of the heart. The modeling framework will be used with left ventricul ar cast data coordinates in future studies. There is presently a lack of three-dimensional data based on a realistic model, and the computat ional method should make it possible to compare simulation results wit h important measurement techniques such as echocardiography and magnet ic resonance imaging.