KISSIMMEE, Fla. — Astros left-hander Mike Hampton is back in camp, relieved that an irregular heartbeat returned to normal without treatment.

Hampton said Wednesday he was nervous after the minor irregularity turned up during a physical when he reported to camp Saturday. After he returned to Houston, another heart test came back normal. He passed a treadmill test Tuesday and returned to Florida.

The 36-year-old Hampton said any issue concerning the heart has to be taken seriously. He said he had a test done eight years ago, after former teammate Darryl Kile died of coronary disease.

Manager Cecil Cooper said Hampton was throwing well before the heart issue arose. Hampton missed all of 2006 and 2007 and was limited to 13 starts last year because of elbow and arm problems.