Pressurised sleeves, placed over the legs, increase the blood pressure flowing back to the heart.

It is believed that this may lead to long-lasting improvements in quality of life by encouraging the development of fresh blood vessels around the diseased organ.

Angina pain - which can be excruciating - happens when furred or hardened arteries severely hamper the blood flow to the heart muscle.

Attacks can be set off by any form of exertion.

Once patients have undergone more than one bypass operation, drugs can only partially relieve the problem.

Another operation to replace hardened arteries supplying the heart may be too risky.

However, the �100,000 leg pump, bought from the US by Hammersmith Hospital in London, and another heart centre in Hull has produced significant and lasting benefits in the majority of patients.

The device involves inflatable pressure pads which are wrapped around the calves, thighs and buttocks of the patient.

Improved blood flow

These then rhythmically squeeze the blood back up the legs to the heart.

Somehow this increased pressure seems to strengthen the heart and improve long-term blood flow to the organ.

Dr Peter Bagger, a consultant cardiologist at Hammersmith Hospital, said: "This treats end-stage angina patients where they are on maximum medication and you can do nothing for them.

"We think it created new blood vessels called collaterals in the heart.