Cubs starting pitcher Carlos Silva left in the first inning of Sunday's game against the Rockies with an irregular heart beat. Silva was examined by Colorado's team doctors before being sent to St. Joseph's Hospital in Denver, where he will spend the night. "He stepped back, we thought something was wrong," acting manager Alan Trammel said. "He has an abnormal heart rate. He's staying overnight for observation is all that I know. He won't be going back [to Chicago] with us tonight."