Our proposed project is for execution of pilot studies using the Endothelial Cell Culture Model (ECCM) developed by Dr. Palaniappan Sethu (Associate Professor of Medicine and Biomedical Engineering, University of Alabama-Birmingham (UAB)) and Dr. Guruprasad Giridharan (Professor, Associate Chair of Bio-Engineering, University of Louisville). Studies will be conducted at UAB to evaluate the acute response of human aortic endothelial cells (HAECs) during temporary circulatory support using a continuous flow roller pump versus the VENTRIFLO True Pulse Pump (n=4 runs/pump). HAECs will be maintained under normal physiologic flow for 24 hours followed by 3 hours under pressure and flow waveforms typically seen using conventional roller pumps as compared to the VENTRIFLO True Pulse Pump. The secretome of HAECs collected at baseline (24 hours) and hourly under the two different flow conditions will be analyzed using Discovery Assay Human Cytokine Array / Chemokine Array 42-Plex with IL-18 (HD42) and Human Angiogenesis Array & Growth Factor 17-plex Array (HDAGP17) for defined analytes. Cell lysates will be banked for future analysis.