Houston ? Nobel laureate and former Polish President Lech Walesa was treated for a clogged coronary artery and will have a heart pacemaker implanted today, doctors said.

Walesa was resting Thursday, a day after doctors at the Methodist DeBakey Heart and Vascular Center implanted a stent into the artery, hospital spokeswoman Erin Fairchild said.

She said he had no procedures scheduled Thursday, but further tests would be done to make sure the stent was working correctly.

Walesa, 64, has been in Houston this week undergoing tests to determine whether he needs a heart transplant. Doctors said they plan to place a pacemaker in Walesa’s chest on Friday.