A heart assist device connection system comprises an inflow connector in fluid-tight communication with an inflow section of a heart assist device. The connector is configured to be releasably connected to an inlet extension inserted into a patient's ventricle. The connector has one or more recesses configured to match a protrusion on the inlet extension. The system also comprises an outflow connector in fluid communication with an outflow section of the heart assist device. The outflow connector is configured to be releasably connected to a conduit attached-to the patient's vasculature.