John Hart, a Coburn spokesman, said that the senator was being tested for a common arrhythmia, The Hill reported. He said that Coburn expects to be back in the Senate on Saturday to vote on the housing bill.
Coburn, 60, an obstetrician, has been twice diagnosed with cancer.
A very conservative senator, Coburn is known for placing holds on bills, a process he says ensures full debate. This week, Majority Leader Harry Reid, D-Nev., said he was creating an omnibus bill with 35 of the most popular bills Coburn has held, bundled into one.