A delivery device for a prosthetic heart valve includes a catheter assembly and an operating handle. The catheter assembly may include an inner shaft around which a compartment for the heart valve is defined, and a distal sheath having proximal and distal segments configured to enclose the compartment. The handle may include a first lead screw coupled to the proximal segment and a second lead screw coupled to the distal segment. Actuation of the first lead screw operates to move the proximal segment of the distal sheath proximally and actuation of the second lead screw operates to move the distal segment of the distal sheath distally to uncover the compartment and deploy the heart valve.