Doctors determined the senior had a cardiac event when she collapsed while on the bench early in Tuesday night's victory against Missouri State, coach Jeff Walz said at a news conference Friday. The clot was discovered during several days of testing to find out what caused the event.
"We're very fortunate this was discovered through testing," Walz said.
Slaughter will immediately begin taking blood thinners. The treatments typically last six to seven months, and competition is prohibited.
"She's disappointed, of course," Walz said. "I'm not sure really it's sunk in yet. We just found out about it last night and sat down with the doctors.
"We're not even discussing her basketball (career) at this point in time. We're more concerned about her health in general and trying to find out why this happened Tuesday night."
Slaughter could be released from the hospital Friday and is expected to see a cardiologist.
The 6-foot-1 Louisville native scored the game's first basket in the No. 7 Cardinals' 91-49 victory. But after leaving the game with 17:13 left in the first half, she suddenly collapsed.
Walz said she showed no signs of feeling ill before the game. He had talked to Slaughter after he took her out, and she was responsive and appeared to be fine.
Slaughter told teammate Tia Gibbs on the bench that she felt dizzy just before collapsing, Walz said.
Louisville (8-1) loses its fifth-leading scorer (9.3 points per game) and most consistent 3-point shooter, who played a key role in the Cardinals' run to last spring's NCAA final. Slaughter started 30 of 38 games as a junior, averaging 10.1 points and 4.9 rebounds while leading the Cardinals at nearly 36 percent from beyond the arc.
Slaughter tied a career best with seven 3-pointers in the stunning upset of top-ranked defending champ Baylor in the regional final.
Walz said "there were a lot of tears shed" by Slaughter's teammates after they learned of the diagnosis.
"The players are definitely a little in shock right now," he said. "I'm really excited for when Antonita can rejoin us. I really do believe when our teammates get the opportunity to see her, and see the smile . . . when they can see that, it will give a little bit of comfort to them."