Senator Bernie Sanders underwent heart surgery after he felt chest discomfort during a Tuesday campaign event.

The Hill reports Jeff Weaver, a senior adviser to the campaign, who revealed two stents were inserted into his heart after a blockage was discovered in two of his arteries.

“Sen. Sanders is conversing and in good spirits,” 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.”

This story is updating.