Ventricular motion during the ejection phase: a computational analysis

In the present paper, the study of the ventricular motion during systole wa s addressed by means of a computational model of ventricular ejection. In p articular, the implications of ventricular motion on blood acceleration and velocity measurements at the valvular plane (VP) were evaluated. An algori thm was developed to assess the force exchange between the ventricle and th e surrounding tissue, i.e., the inflow and outflow vessels of the heart. Th e algorithm, based on the momentum equation for a transitory flowing system , was used in a fluid-structure model of the ventricle that includes the co ntractile behavior of the fibers and the viscous and inertial forces of the intraventricular fluid. The model calculates the ventricular center of mas s motion, the VP motion, and intraventricular pressure gradients. Results i ndicate that the motion of the ventricle affects the noninvasive estimation of the transvalvular pressure gradient using Doppler ultrasound. The VP mo tion can lead to an underestimation equal to 12.4 +/- 6.6%.