An intra-atrial pump (IAP) was proposed that would be affixed to the atrial septum to support the compromised left ventricle (LV) without harming the ventricular tissue in patients with early-stage heart failure. The IAP is designed to operate in parallel with the LV, drawing blood from the left atrium and unloading the LV. In previous hydraulic studies, different blade geometries were tested for the IAP; however, it is important to know how the blade geometry affects the IAP's hemodynamic performance in the human cardiovascular system. In this study, a mock circulatory loop (MCL) with physiological response was used to evaluate the hemodynamic effects of IAP blade geometry and connection configuration in the human cardiovascular system. In a $2 \times 2$ study, two different blade geometries (with steep vs flat pressure/flow curves) were tested in two different connection configurations: the proposed configuration (left atrium to aorta) and the conventional configuration for LVADs (LV to aorta). We found that atrial cannulation is feasible and creates a beneficial hemodynamic environment, although it is inferior to the one created by ventricular cannulation. The steepgradient pump performed better than the flat-gradient pump in atrial insertion.