Democratic presidential candidate Bernie Sanders had a heart attack, his campaign has confirmed as the Vermont senator was released from a Nevada hospital.
Sanders, 78, said he felt "great", according to a statement from his campaign for the 2020 Democratic presidential nomination.
"Sen. Sanders was diagnosed with a myocardial infarction," his doctors said in the statement, using the medical term for a heart attack.
"Two stents were placed in a blocked coronary artery in a timely fashion. All other arteries were normal. His hospital course was uneventful with good expected progress."
Sanders put his bid for the White House on hold after experiencing chest discomfort while on the stump in Las Vegas on Tuesday.
"After two and a half days in the hospital, I feel great, and after taking a short time off, I look forward to getting back to work," Sanders said.
The far-left senator from Vermont is expected to participate in the fourth Democratic debate scheduled for October 15 in Ohio.
Sanders, who pushed Hillary Clinton to the wire for the Democratic nomination in 2016, was at a campaign event when he experienced chest discomfort and was taken to a hospital where he was diagnosed with a heart attack. The senator was transferred to Desert Springs Hospital Medical Centre where doctors inserted two stents to open up a blocked artery in his heart, according to a statement from the Las Vegas doctors.
The doctors, Arturo Marchand, Jr. and Arjun Gururaj, said the rest of his arteries were normal.
A blocked artery can cause a heart attack, which means that an area of the heart is suffering and in danger of damage because it's not getting enough blood or oxygen. An artery-opening procedure like the one Sanders had, and placing stents, which are tiny scaffolds to keep the artery open, restores blood flow and helps prevent future problems.
The statements from Sanders and his doctors do not indicate whether his heart suffered any permanent damage, or the extent of any. The sooner blood flow is restored, the better the chance of survival without damage, which is why heart experts urge anyone thinking they might be having a heart attack to call emergency services.
Questions over Democrats' ages
Sanders is the oldest candidate vying to take on President Donald Trump, 73, and is third in the Democratic nominee polls behind Joe Biden, 76, and Elizabeth Warren, 70.
Sanders' health has generally been good and it has been Biden who has had to bat away questions about his stamina and mental sharpness.
In March, Sanders gashed his head on a shower door and had seven stitches, but quickly returned to the campaign trail.
Last month, he cancelled three events in South Carolina to rest his voice, which had become hoarse.
Sanders, a self-described Democratic socialist, wants to tax the rich more and introduce universal health care.
He has sometimes jokingly referenced his age on the campaign trail. He is one of three septuagenarians who are leading the crowded race and have sparked questions within the party about whether Democrats need to coalesce around a younger leader.
President Donald Trump is 73.