Former US President Bill Clinton has successfully undergone a five-hour quadruple heart bypass operation to relieve clogged arteries, say doctors.
Bill Clinton left the White House in 2001
Dr Craig Smith, who led the operation at New York Presbyterian Hospital, said Mr Clinton was recovering normally.
Mr Clinton, 58, was admitted to hospital three days ago suffering chest pains and shortness of breath.
More than 26,000 people from all over the world have sent messages wishing him a speedy recovery.
Dr Smith, the hospital's chief of cardiothoracic surgery, told a news conference four hours after the operation: "He is recovering normally at this point. I think right now everything looks straightforward."
Another member of the medical team, cardiology chief Dr Allan Schwartz, said Mr Clinton was awake but still sedated and had not yet spoken.
The former president's wife Hillary and daughter Chelsea were by his bedside as he recovered from surgery.
Bypass operations, in which sections of the patient's own blood vessels are grafted to bridge over blockages in the heart's arteries, have become a common and usually successful procedure in recent years.
Mr Clinton's operation began at 0700 local time (1100 GMT) on Monday and lasted nearly five hours.
Mr Clinton served two terms as president, during which he became known for his love of fast food and jogging.
Correspondents say he may now have to scale down his role in the Democrat campaign for November's elections.
'Caught in time'
During his own presidency, Mr Clinton showed no signs of heart problems during rigorous health examinations that were made public.
In recent months, Mr Clinton has appeared trim and well - which he attributed to following the "South Beach Diet" of lean meat and unprocessed food.
The former president and his family issued a statement on the Clinton Foundation's website on Sunday, saying they felt "blessed and grateful for the thousands of prayers and messages of goodwill we have received these past few days".
President George W Bush and Democratic presidential contender John Kerry, both busy on the campaign trail ahead of November's elections, sent their best wishes to Mr Clinton before the operation.
The BBC's Jeremy Cooke in New York says the former president had promised to be a loyal "foot soldier" in Mr Kerry's drive to win the White House, but his involvement may now be limited.
However, our correspondent says Mr Clinton had a 90-minute telephone conversation with Mr Kerry on Sunday to discuss campaign strategy.
Known as a formidable campaigner, Mr Clinton gave a speech to the Democratic Party convention in Boston in July that was seen as one of the highlights.
Observers say his natural flair among crowds could have been used to boost the campaign of Mr Kerry, who is regarded as somewhat aloof.
HEART BYPASS OPERATION
One or more arteries supplying the heart with blood become blocked, often by fatty deposits.
Blood vessels are taken from other parts of the body - usually internal mammary arteries supplying blood to the breastbones, but also possibly from the leg or arm.
During surgery, the heart may be stopped and the heart and lungs linked to a machine to continue circulating blood around the body.
The vessels are grafted on, from the aorta (the main artery leaving the heart) to a clear part of the artery beyond the blocked area.