Democratic presidential candidate Sen. Bernie Sanders (I-Vt.) underwent an emergency heart procedure following a campaign event Tuesday evening, his campaign confirmed in a statement.

“During a campaign event yesterday evening, Sen. Sanders experienced some chest discomfort,” the campaign said in an emailed statement. “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.”

“He will be resting up over the next few days,” the statement read.

Sanders’ campaign is canceling his events until further notice.

The Sanders campaign has also canceled its TV advertising spending in Iowa, according to political ad tracker Medium Buying. It had originally planned to start airing ads Thursday.

Campaign rivals including Sen. Elizabeth Warren (Mass.), former Vice President Joe Biden and South Bend, Indiana, Mayor Pete Buttigieg were quick to tweet messages of support and encouragement.

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

Bernie himself posted on Twitter Wednesday afternoon, expressing gratitude both for his health care staff and his access to good care.