Rep. John Dingell (D-Mich.) will undergo a minimally invasive heart procedure in Detroit on Thursday, according to a statement from his office.
“He recently developed atrial fibrillation, and the procedure will seek to find the source of the abnormal heart rhythm and correct it," the statement said. "He is expected to stay in the hospital overnight and be released Friday."
His office did not specify the type of procedure that will be conducted, or any further details about the congressman’s condition.
Dingell, 87, is the longest-serving member of Congress ever, and he announced last month he won’t seek reelection this year. He has served 60 years in the House.
The Democrat has suggested age and health, as well partisanship on Capitol Hill, were factors in his retirement.
"I've reached the age when people don't buy green bananas," he said in his retirement announcement, according to USA Today.
In recent years, Dingell has had to use crutches or a wheelchair to get around.
The lawmaker's wife, Debbie Dingell, is running for her husband's seat in November.