Flow patterns in three-dimensional left ventricular systolic and diastolic flows determined from computational fluid dynamics

Article type: Research Article

Authors: Taylor, T.W. | Yamaguchi, T.

Affiliations: Department of Bio-Medical Engineering, School of High-Technology for Human Welfare, Tokai University, 317 Nishino, Numazu, Shizuoka 410-03 Japan

Abstract: A realistic model of the left ventricle of the heart was previously constructed, using a cast from a dog heart which was in diastole. Previous studies of the three-dimensional heart model were conducted in systole only. The purpose of this investigation was to extend the model to both systole and diastole, and to determine what the effect of a previous cardiac cycle was on the next cardiac cycle. The 25.8 cc ventricular volume was reduced by 40% in 0.25 seconds, then increased to the original volume in another 0.25 seconds and then allowed to rest for 0.25 seconds. Runs done with an ejection fraction of 60% showed little variation from one cardiac cycle to another after the third cardiac cycle was completed; the maximum velocity could vary by over 30% between the first and second cardiac cycles. In systole, centerline and cross-sectional velocity vectors greatly increased in magnitude at the aortic outlet. Most of the pressure drop occurred in the top 15% of the heart. The diastolic phase showed complex vortex formation not seen in the systolic contractions; these complex vortices could account for experimentally observed turbulent blood flow fluctuations in the aorta.

Keywords: Computational fluid dynamics, heart, blood flow, left ventricle, systole, diastole

DOI: 10.3233/BIR-1995-32105

Journal: Biorheology, vol. 32, no. 1, pp. 61-71, 1995