The Navy said it will court-martial Dr. Donal M. Billig, the former chief of heart surgery at Bethesda Naval Medical Center, on four counts of involuntary manslaughter and 22 counts of dereliction of duty. The manslaughter counts have been filed in connection with the deaths of four patients while Billig served at the hospital, the Navy said. In addition, 10 other officers are facing or have already received disciplinary sanctions for their involvement in the recruitment or oversight of Billig. Billig was suspended from practice at the “hospital of Presidents” in 1984. He was formally ousted in April.