Icon Paul McCartney is recovering after undergoing a secret heart operation.The 65-year-old underwent a coronary angioplasty - a procedure to open up arteries, allowing a greater flow of blood to and from the heart, late last year. But the star has made a good recovery and he appeared onstage with Pop singer Kylie Minogue for a televised concert on New Year’s Eve. A source tells London's newspaper The Sun, "Paul had been complaining about not feeling well and saw a Harley Street specialist at The London Clinic."Tests were carried out and the decision was taken to operate. Paul had the angioplasty in a private hospital. It was all very routine but any work on your heart is a big deal." A spokesman for McCartney confirmed the surgery adding, "It was a routine medical operation."