Cheney has surgery for artery blockage

United States Vice President Dick Cheney has undergone an angioplasty procedure for a partially-blocked artery after going to hospital with chest pains.

The artery, which had been opened in late November, had partially reclosed, his cardiologist, Dr Jonathan Reiner, told reporters in Washington.

There was no evidence that Mr Cheney had suffered another heart attack, he said.

Mr Cheney, 60, suffered the more recent of his four heart attacks in late November, but quickly resumed a full schedule after an operation to open the blocked artery.

Dr Reiner said he did not believe Mr Cheney had suffered any additional heart damage.

The vice president checked himself into the hospital after feeling chest pain briefly on two occasions after earlier episodes over the weekend.

The episodes were "much milder and very brief" when compared with the chest pains that he suffered in November, Dr Reiner said, adding that "the symptoms were subtle" this time.

In an angioplasty, doctors insert a flexible tube carrying a collapsed balloon into the narrowed artery. Once the balloon is in place, it is inflated, reopening the artery.

During the procedure last November, one of Mr Cheney's heart arteries was 90% blocked, so doctors implanted a wire scaffolding-like device called a stent to push away the blockage and prop open the artery walls.

The vice president was expected to spend the night in hospital and to be released on Tuesday.