A delivery device for percutaneously deploying a stented prosthetic heart valve including a stent frame to which a valve structure is attached, the device comprising: a delivery sheath terminating at a distal end and defining a lumen; an inner shaft assembly slidably disposed within the lumen and including an engagement structure configured to selectively engage a prosthetic heart valve; and a release assembly disposed between the delivery sheath and the inner shaft assembly, the release assembly defining a central axis and including: a base coupled to the inner shaft assembly proximal the engagement structure, a retraction member distal the base and configured to self-retract in longitudinal length from an extended condition to a relaxed, retracted condition, a release member distal the retraction member and configured to self-expand in radial projection relative to the central axis from a compressed condition to a normal, expanded condition, a retention member distal the release member; wherein the device is configured to provide: a delivery state in which the distal end of the delivery sheath is distal the retention member, the release member is in the compressed condition, and the retraction member is in the extended condition, a deployment state in which the distal end of the delivery sheath is proximal the release member, the release member is in the normal, expanded condition, and the retraction member is in the relaxed, retracted condition. a delivery sheath terminating at a distal end and defining a lumen; an inner shaft assembly slidably disposed within the lumen and including an engagement structure configured to selectively engage a prosthetic heart valve; and a release assembly disposed between the delivery sheath and the inner shaft assembly, the release assembly defining a central axis and including: a base coupled to the inner shaft assembly proximal the engagement structure, a retraction member distal the base and configured to self-retract in longitudinal length from an extended condition to a relaxed, retracted condition, a release member distal the retraction member and configured to self-expand in radial projection relative to the central axis from a compressed condition to a normal, expanded condition, a retention member distal the release member; a base coupled to the inner shaft assembly proximal the engagement structure, a retraction member distal the base and configured to self-retract in longitudinal length from an extended condition to a relaxed, retracted condition, a release member distal the retraction member and configured to self-expand in radial projection relative to the central axis from a compressed condition to a normal, expanded condition, a retention member distal the release member; wherein the device is configured to provide: a delivery state in which the distal end of the delivery sheath is distal the retention member, the release member is in the compressed condition, and the retraction member is in the extended condition, a deployment state in which the distal end of the delivery sheath is proximal the release member, the release member is in the normal, expanded condition, and the retraction member is in the relaxed, retracted condition. a delivery state in which the distal end of the delivery sheath is distal the retention member, the release member is in the compressed condition, and the retraction member is in the extended condition, a deployment state in which the distal end of the delivery sheath is proximal the release member, the release member is in the normal, expanded condition, and the retraction member is in the relaxed, retracted condition.