Implantation of repair chords in the heart

Apparatus, comprising:

• a rotatable structure having a first end shaped to define a first opening, and a second end shaped to define a second opening, the rotatable structure being shaped to define a channel extending from the first opening to the second opening, the channel being configured for passage therethrough of an elongate tool, and the second end of the structure having a lower surface thereof shaped to:
• provide at least a portion thereof having a circumference, and
• define one or more recesses at locations along the circumference;
• and
• a mechanical element having a surface coupled to the lower surface of the rotatable structure, the mechanical element being shaped to provide:
• a protrusion protruding out of a plane of the surface of the mechanical element, the protrusion being disposed within one of the recesses during a resting state of the mechanical element, in a manner that restricts rotation of the rotatable structure, and
• a depressible portion coupled to the protrusion, the depressible portion being disposed in communication with the second opening of the lower surface, and configured to dislodge the protrusion from within the recess in response to a force applied thereto by the elongate tool.