Sir David Attenborough, 86, still his 'lively self' following urgent heart surgery

Veteran BBC broadcaster Sir David Attenborough underwent successful heart surgery to fit a pacemaker in London today.

The 87-year-old, who was forced to cancel a trip to Australia, had been told by his cardiologist “that he is in urgent need of a pacemaker,” according to a statement from his publicist.

A spokesman for the naturalist said the TV star was doing well following the procedure today.

He said: "Sir David has now had the operation and his doctors are satisfied with his progress."

The presenter of award-winning programmes such as Life on Earth and The Living Planet was due to embark upon a sold-out speaking tour of Australia next week.

The trip, which was due to start in Brisbane, has now been cancelled while Sir David remains in the UK for treatment. The statement expressed his “extreme disappointment” at its postponement and said he hopes to reschedule the tour as soon as he recovers from surgery.

His spokesman earlier told PA that Sir David was still his "lively self" and the described the operation as a "minor procedure".

Sir David has spent six decades presenting programmes for the BBC. He recently unveiled a new slot for Radio 4 called Tweet Of The Day. Each episode lasts a minute and a half and features the song of a particular species of bird.

Speaking in January about his age, Sir David said: “I'm 86 now and I've been broadcasting for 60 years. I don't want to slow down. Retirement would be so boring.”

The broadcaster, who was born in Isleworth, London in 1926, is the only person to have won a Bafta award for programmes in black and white, colour, HD and 3D.

Sir David has been named Britain's greatest living national treasure.