Democratic presidential hopeful Bernie Sanders had a heart procedure after suffering chest discomfort during a campaign event Tuesday evening in Las Vegas, a top campaign aide confirmed Wednesday.

“Following medical evaluation and testing, he was found to have a blockage in one artery and two stents were successfully inserted. Sen. Sanders is conversing and in good spirits,” senior campaign adviser Jeff Weaver said. "He will be resting up over the next few days. We are canceling his events and appearances until further notice, and we will continue to provide appropriate updates.”

Sanders, 78, later wrote on Twitter that he was "feeling good" and that his medical episode underscored the need for Medicare for All, his signature policy proposal that would lead to a massive expansion of the government backed health-care system while doing away with private insurance.

"I'm fortunate to have good health care and great doctors and nurses helping me to recover," Sanders added. "None of us know when a medical emergency might affect us. And no one should fear going bankrupt if it occurs. Medicare for All!"

The Vermont senator is among the top contenders vying for the 2020 Democratic nomination. He trails former Vice President Joe Biden and Sen. Elizabeth Warren in the polls.

Sanders has kept a breakneck campaign schedule since entering the race in February and has been a prolific fundraiser. He announced this week that he had collected $25.3 million from small donors – the largest quarter for any Democratic candidate this year.

The Democratic socialist has boasted that most of his campaign war chest comes from small donors.

The heart problem led to the postponement of a $1.3 million television advertising buy in Iowa this week, said the campaign's Midwest spokesman, Bill Neidhardt.

Sanders had been scheduled to take part in a gun safety forum in Las Vegas on Wednesday and campaign in California in the coming days.

President Donald Trump's reelection campaign and Sanders' Democratic presidential rivals took to social media to wish the Vermont senator a speedy recovery.

Tim Murtaugh, the Trump campaign's communication director, said his team sent Sanders "our prayers and wish him a speedy recovery."

Biden tweeted: "Anyone who knows Bernie understands what a force he is. We are confident that he will have a full and speedy recovery and look forward to seeing him on the trail soon."

Warren said, "Bruce, Team Warren, and I are sending all our best wishes for a speedy recovery to@BernieSanders. I hope to see my friend back on the campaign trail very soon."

"Thinking of @BernieSanders today and wishing him a speedy recovery," Sen. Kamala Harris, another 2020 Democratic contender, tweeted. "If there's one thing I know about him, he's a fighter and I look forward to seeing him on the campaign trail soon."

The Vermont senator is one of four septuagenarians battling for the White House in 2020.

Does age matter? Trump vs. Biden in Iowa: Septuagenarian rivals try to demonstrate vigor in head-to-head stops

Trump is 73, Biden is 76 and Warren is 70.

The age of the contenders has been mostly a backburner issue in the campaign.

Forty-six percent of voters planning to attend Iowa’s Democratic caucuses said it would be a disadvantage for a candidate to be older than 70, and 50% said it would make no difference, according to a Des Moines Register/CNN/Mediacom poll published in June. Three percent said they were unsure, and 1% said it would be an advantage.

The stent procedure comes at a moment when Sanders – despite maintaining a strong fundraising haul – had found his candidacy in a “slow-moving decline” as fellow progressive candidate Warren has moved up in the polls, said Daniel Schlozman, a political scientist at Johns Hopkins University.

In his unsuccessful 2016 run for the Democratic nomination, Sanders found success in his head-to-head competition consolidating a range of opposition among Democratic primary voters to former Secretary of State Hillary Clinton and those on the left who questioned the centrist trajectory of the party.

But in a crowded field – there are still 19 major Democratic candidates vying for the nomination – Sanders has had more difficulty making headway with voters. He stands in third place in national polling, according to a Real Clear Politics' averaging of major polls. Sanders also sits in third place in polling of three of the first four caucus and primary states.

“As of yesterday, Sanders faced strategic challenges in a multi-candidate race, where he faced a closely (ideologically) aligned and fast-rising candidate in Elizabeth Warren,” Schlozman said. “Those challenges haven’t disappeared, and now there is a new concern on top of them.

"How he thinks his way through the issues of age and health is another difficult issue for a campaign that was already facing a ceiling as far as we could see unless something pretty substantial happened to shake the field out.”

Contributing: Nick Coltrain in Des Moines