The 54-year-old country music star had the operation Wednesday night at the Baylor Heart Hospital in Plano, Texas.
The stroke is "a complication of his congestive heart failure" Travis' representative Kirt Webster told CNN Thursday.
"We will have updates as they become available," Webster said. "His family and friends here with him at the hospital request your prayers and support."
Before the stroke, doctors said Travis was showing signs of improvement.
Travis last month completed his court-ordered rehab stemming from a 2012 drunken driving arrest and was touring again when he was struck down by pneumonia, which led to complications of viral cardiomyopathy and congestive heart failure.