HOUSTON — Nine years after her husband died unexpectedly in a hospital, Linda Carswell is still fighting to get his heart back. Jerry Carswell, a state championship-winning high school track coach, died in 2004 while hospitalized for kidney stones. Christus St. Catherine Hospital, where he died, promised a full autopsy, but did not perform toxicology tests that could have determined whether the painkillers Carswell was given had anything to do with his death. His heart was also kept by the hospital that conducted the autopsy — something Linda Carswell found out well after her husband's burial.