Three dimensional numerical assessment of the right ventricular flow using 4D echocardiography boundary data

Adequate cardiac performance is maintained by the synergistic function of the heart chambers and valves. Left ventricular flow and output have been attributed the major role as an index of cardiac wellness, yet it works simultaneously with the right ventricle (RV) to sustain proper blood circulation. However, the multidirectional pattern of flow within the RV has not yet been characterized in detail. To this end the work herein explores the flow in the RV chamber through direct numerical simulations inside a dynamic RV geometry obtained by 40 echocardiography imaging. The RV endocardial geometry extracted through a cardiac cycle was used as the immersed boundaries within a computational box and solved for the Navier-Stokes equation to obtain the three dimensional flow velocities and vortex patterns. Results showed the development of a vortex ring past the tricuspid orifice in early diastole, yet it quickly broke into a weakly turbulent flow (mid-late diastole) absent of any coherent pattern. After the onset of systole a peculiar stream-wise vortex endured adjacent to the free wall side, stretching out towards the pulmonary orifice. This systolic vortex (helical flow) corresponds to a velocity spinning out towards the pulmonary orifice giving a left handed helicity to the flow in the ejected stream. These features are believed to contribute to the adequate mixing of the systemic venous streams in the ventricle and prevent stagnation. This technique allowed for full visualization of the complex multidirectional flow within the cardiac chamber in relation to the peculiarity of the RV geometry. Further work is yet needed at correlating these findings with multidirectional flow acquired in vivo. (c) 2012 Elsevier Masson SAS. All rights reserved.