Letang's condition is not believed to be career threatening and is treatable with blood thinners. Testing revealed that Letang, who has missed Pittsburgh's past four games, has had a small hole in the wall of his heart since birth, a defect that occurs in all individuals before birth but seals shut in most people.
The hole could have led to Letang's stroke, according to a Penguins press release.
"Kris had one brief episode of dizziness and nausea last week," Penguins general manager Ray Shero said in the release. "We held him out of the Los Angeles game [Jan. 30], and when he continued to feel ill, tests conducted in Phoenix on Saturday gave us the first indication of his condition. Further testing then was conducted when he returned to Pittsburgh and he continued to undergo a battery of tests here this week."