A holder for a prosthetic mitral heart valve that attaches to an inflow end of the valve and includes a simple tensioning mechanism that flexes the heart valve commissure posts inward to help prevent suture looping. The tensioning mechanism may include relatively movable rings of the holder or a generally unitary holder with a tensor, or rotatable knob. Connecting sutures thread through internal passages in the holder and travel in the outflow direction along valve commissure posts, emerging at the post tips and mutually crossing over the outflow side of the valve. A handle attaches off-center on the holder to increase visualization of and access to the heart valve through a central window for enhanced access to the commissure posts and leaflets. The holder is constructed of non-metallic materials so as to avoid interfering with imaging devices, and the handle is ergonomically curved and shaped to facilitate manipulation.
