Impact of heart failure severity on ventricular assist device haemodynamics: a computational study

Abstract

Abstract Purpose This computational fluid dynamics study investigates the necessity of incorporating heart failure severity in the preoperative planning of left ventricular assist device (LVAD) configurations, as it is often omitted from studies on LVAD performance. Methods A parametric study was conducted examining a common range of LVAD to aortic root flow ratios (LVAD/AR-FR). A normal aortic root waveform was scaled by 5–30% in increments of 5% to represent the common range of flow pumped by the left ventricle for different levels of heart failure. A constant flow rate from the cannula compensated for the severity of heart failure in order to maintain normal total aortic flow rate. Results The results show that LVAD/AR-FR can have a significant but irregular impact on the perfusion and shear stress-related haemodynamic parameters of the subclavian and carotid arteries. Furthermore, it is found that a larger portion of the flow is directed towards the thoracic aorta at the expense of the carotid and subclavian arteries, regardless of LVAD/AR-FR. Conclusion The irregular behaviour found in the subclavian and carotid arteries highlights the necessity of including the LVAD/AR-FR in the preoperative planning of an LVAD configuration, in order to accurately improve the effects on the cardiovascular system post implantation.