Senator John Boozman of Arkansas was recovering from heart surgery on Tuesday, his office said in a statement.
The 63-year-old Republican was taken to a hospital in Rogers, Arkansas, overnight after experiencing pain in his chest and arm and "responded well" to the surgery, the statement said.
"Boozman's family has visited with him and are hopeful for a full recovery," the statement said.
Boozman won his first term in the Senate in 2010 after serving five terms in the U.S. House of Representatives.
(Reporting by Colleen Jenkins; Editing by Scott Malone and Chizu Nomiyama)