Feds ramp up criminal investigation of 4 Tenet Healthcare hospitals in Atlanta

Federal investigators have ramped up a criminal investigation of four Tenet Healthcare Corp. hospitals in metro Atlanta. Dallas-based Tenet (NYSE: THC) reported Tuesday that on May 6 it received a grand jury subpoena from the U.S. Department of Justice seeking additional documents involving four Tenet hospitals as well as other hospitals in the company's southern region. The hospitals involved include Atlanta Medical Center, South Fulton Medical Center, North Fulton Regional Medical Center and…