Denver - Chicago Cubs starter Carlos Silva left Sunday's game against the Colorado Rockies during the first inning because of an irregular heart rate.
Silva received the loss despite facing just four batters, allowing two hits and two runs. He complained of difficulty breathing and was removed, and paramedics diagnosed him with the abnormal heart rate.
He was taken to a local hospital, where he will remain overnight for observation. His heart rate was back to normal at the hospital.
It is currently unknown whether the ailment will force Silva from his next start.