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Category: 45. Biomedical Computing/Information TechnologySession-Poster Board Number: 1135-137Authors: Salvatore Chiaramida, Matt Luff, Michael L. Bernard, John M. Toole, Adrian B. Van Bakel, Jennifer L. Peura, Ying Sun, Medical University of South Carolina, Charleston, SC, University of Rhode Island, Kingston, RI Background: Standard connection of the left ventricular assist device (LVAD) is from left ventricle (LV) to aorta (Ao). Left atrium (LA) is a possible alternative for LVAD drainage, but has not been fully characterized. In this study a computer model provides a comparison between LA and LV for LVAD drainage in terms of hemodynamic effects on the circulatory system.Methods: Computer simulations were based on an electrical analog model of the circulatory system with a continuous-flow LVAD. The connection of the LVAD is either from LV to Ao or from LA to Ao. A total of 28 nonlinear differential equations were numerically integrated to generate hemodynamic waveforms at various parts of the circulatory system.Results: Figure shows LV and LA pressure-volume loops for A) congestive heart failure, B) LVAD with LV drainage, and C) LVAD with LA drainage. In B the LVAD flow (Qlvad) is adjusted to achieve a 95% assist ratio. In C Qlvad is adjusted to achieve the same cardiac output (CO) as in B. Table summarizes hemodynamic effects in terms of CO, LV ejection fraction (EF), arterial blood pressure (BP), and pulmonary capillary wedge pressure (PCWP).Conclusions: LVAD with LA unloading has the advantage of allowing for a higher LV systolic function, thereby achieving the same level of cardiac output with a lower assist ratio.