A device for performing minimally invasive repair of mitral valve leaflets in a beating heart through the delivery and implantation of artificial chordae tendineae includes a handle for positioning the device into a chest cavity of the patient, a capture assembly adapted to capture a valve leaflet between distal an proximal tip portions, a needle adapted to penetrate the valve leaflet, and a capture confirmation system for verifying capture of the valve leaflet between the distal and proximal tip portions.