Described herein are systems for partitioning a ventricle of a heart. The systems may include a partitioning device or implant, and an applicator for inserting, repositioning and/or removing the partitioning device. The implant may support the ventricle wall and may reduce the volume of the ventricle. In particular, described herein are systems for delivering and deploying a partitioning device into a ventricle. The delivery system may include a catheter having a distal coupling element for coupling to a partitioning device in a collapsed configuration; the catheter may also have an expansion member for applying force to the partitioning device to fully expand it into a deployed configuration and to secure or seal it against the ventricle wall.