Beloved British nature broadcaster Sir David Attenborough has vowed to keep on working despite undergoing emergency heart surgery in June (13). The 87-year-old was forced to cancel a speaking tour of Australia to have a pacemaker fitted after a cardiologist determined him in urgent need of the specialist device. But the naturalist, who is the younger brother of movie legend Lord Richard Attenborough, insists that the operation has actually inspired him to maintain his hectic schedule. Speaking at the launch of his new nature film Penguins 3D he said, "If you're in your late 80s as I am, and your heart needs to be helped with collaborations, then it is easily fitted with (a pacemaker). You just go in for 24 hours and it's done. I don't think it has made me reassess my work at all or any trips ahead. It allows one to continue the way one does until one can't, doing what I enjoy."