Cheney prepares to return to work

US Vice-President Dick Cheney is resting at home as he adjusts to his new pacemaker and prepares for a return to his White House duties tomorrow.

White House spokeswoman Juleanna Glover Weiss says Mr Cheney is relaxing and looking forward to being back at work.

She says Mr Cheney has read and reviewed papers at his official residence after his doctors gave him permission to resume his exercise routine.

The dual-purpose pacemaker was implanted in Mr Cheney's chest during an hour-long procedure on Saturday at George Washington University Hospital.

It works like any other pacemaker by assuring that his heart does not beat too slowly. When it detects the beat slowing below a certain level, it sends a mild electric charge to pace the beat at a minimum level.

More dramatically, if the heart suddenly surges to a dangerous, high-speed beat, the ICD defibrillator kicks in - sending an electrical jolt to the lower chamber of the heart and causing it to slow down.

Some times, this will cause the heart to slow too much and that is when the pacemaker turns on and adjusts the rhythm.

Dr Douglas Zipes, head of the American College of Cardiology and an authority on irregular heart rhythms, says that jolt could be jarring for Mr Cheney.

Dr Zipes, who was consulted by the vice-president's doctors, says: "That is something he will feel, and patients describe it anywhere from a giant hiccup to a mule kick in the chest.

"With an electric shock, it contracts all of the muscles, not just the heart but the chest muscles too."