A sterile implantable cord intended to be used as an artificial substitute for the chordae tendinae (heart strings) to restore natural function to a defective (regurgitant, prolapsed) mitral valve. The implantable cord is delivered via transapical access to the beating heart through a mini-thoracotomy. It is a suture-like string made of synthetic polymer materials [e.g., expanded polytetrafluoroethylene (ePTFE) fabric], and is attached between the valve leaflet and the epicardium with a dedicated, disposable, manually-operated delivery tool (included).