A cannula for implantation into a chamber of a heart includes an elongate body having a lumen extending along a longitudinal axis, a first end, and a second end. The first and second ends define openings into the lumen and the second end includes a flat portion. A flared tip portion extends from the flat portion of the second end in a direction toward the first end, and flares radially outward from the longitudinal axis and in such direction. A ring member extends around the axis of the elongate body and is spaced from the flared tip portion, and the ring member is adapted for retaining the elongate body in a position relative to a wall of the chamber. An embodiment of a flared tip portion may further include a barbed surface configured to contact tissue around an aperture in the wall of the heart when the cannula travels through the aperture.