SAN FRANCISCO — Chicago Cubs pitcher Carlos Silva underwent a procedure called cardiac ablation on Monday to correct a problem with his heart rate.
The Cubs hope he will return to the mound sometime this season.
Silva underwent the approximately two-hour surgery Monday morning at Northwestern Memorial Hospital, performed by Dr. Bradley Knight. Without the procedure, the rapid heart rate could have recurred at any time.
He was discharged from the hospital after what the team called a normal period of observation.
"Trainer Mark O'Neal said he did very well," said Alan Trammell, the Cubs' acting manager while Lou Piniella is helping his ailing mother in Tampa, Fla. "It's a wonderful procedure. He should be back doing something later in the week and we'll see where it leads."
Teammate Carlos Zambrano spoke to Silva on Monday before Zambrano was set to start against the San Francisco Giants.
"He told me he feels OK," Zambrano said. "I wish the best for him."
Silva spent a night in a Denver hospital Aug. 1 after the right-hander left in the first inning of his start that day against the Colorado Rockies with an abnormal heart rate. He was placed on the disabled list the following day.
The Cubs expect Silva, who is 10-5 with a 3.92 ERA this season, to begin light physical activity this week and start a throwing program early next week.
"That's too bad," San Francisco manager Bruce Bochy said. "He was having a nice year. That's a scary situation. I'm glad they found it and are taking care of it. Even though you're an athlete, or a major league athlete, you're vulnerable. I'm glad they took him out when they did."
Silva had the same procedure as former Cubs player Mark DeRosa, now with the Giants and on the disabled list following wrist surgery. DeRosa had the heart work done during spring training 2008 and was able to play in 149 games that season.
Also Monday, Cubs first baseman Derrek Lee left the team to travel to his native Sacramento to be with his ill grandfather. The Cubs expected to know more late Monday about whether Lee would return for Tuesday night's game or perhaps need a stint on the bereavement list.
Catcher Geovany Soto was a late lineup scratch by the Cubs because of a sprained right shoulder ligament. He missed his third straight game. Soto tested his shoulder, which bothers him only at the plate, during early batting practice and was fine but during later warmups experienced some discomfort.