A catheter device for repair of the heart by implanting an artificial chord is disclosed. The device comprises a leaflet anchor 10 for placement in a leaflet 12 of a heart valve, wherein the leaflet anchor 10 is arranged to be coupled to the artificial chord 14； and a mechanical gripper device 6 for grasping the leaflet 12 of the heart valve, wherein the gripper device 6 comprises a leaflet anchor channel for housing the leaflet anchor 10 in a folded configuration； the gripper device 6 and leaflet anchor 10 being arranged such that when, in use, the gripper device 6 grasps the leaflet 12, the leaflet anchor 10 can be pushed out of the leaflet anchor channel to pierce the leaflet 12 and form the leaflet anchor 10 into an unfolded configuration so that hooked formations of the leaflet anchor 10 can, in use, secure the leaflet anchor 10 in the leaflet 12.
