A realistic model of the left ventricle of the heart was constructed using a cast from a dog heart which was in diastole. A coordinate measuring machine was used to measure and digitize the coordinates of the left ventricle. From the complex measured left ventricle shape values, a three dimensional finite volume representation was constructed using a simulation package. The left ventricular walls moved towards the center of the aortic outlet in order to study the effects of time varying left ventricular ejection. The left ventricular wall motion was assumed to follow the blood flow and the wall grid was reformed 25 times during the calculation. The 25.8 cc ventricular volume was reduced to 75% in 0.25 seconds. Centerline and cross-sectional velocity vectors greatly increased in magnitude at the aortic outlet, and most of the pressure occurred in the top 15% of the heart. The computational method should make is possible to compare simulation results with important measurement techniques such as ultrasound and magnetic resonance imaging and this should allow a finer detail of flow understanding than is presently available using either a modeling or imaging method alone.