Three military retirees -- one each from the Air Force, Army and Navy -- and the wife of a retired marine are the four heart patients whose deaths at Bethesda Naval Hospital led to court-martial charges against Cmdr. Donal M. Billig, the Navy said yesterday.

The patients identified yesterday by the Navy were: Joe B. Estep, 66, a retired Navy petty officer from Temple Hills, who died Oct. 18, 1984; Harold Coplan, 59, a retired Air Force lieutenant colonel from Gaithersburg, who died March 1, 1983; William Franklin Grubb Jr., 73, a retired Army major from Lancaster, S.C., who died Aug. 8, 1984; and Lois Parent, the wife of retired Marine Sgt. Maj. Maurice Parent of Havelock, N.C., who died Nov. 2, 1984.

The patients died, the Navy has charged, as a result of artery bypass operations performed by Billig, a surgeon at Bethesda, one of the Navy's premier hospitals. According to documents released yesterday, Billig, 54, tore and improperly repaired the main heart arteries during operations involving two of the patients and improperly grafted large veins to very small arteries during a heart operation of another.

Those descriptions are included in a formal order from the Navy that outlines the military court proceedings, to be heard by nine senior-level officers that Billig will face next month. Ten other Navy officers have received or are facing disciplinary sanctions in connection with the Billig prosecution.

"I just found out this morning," said Kiyomi Estep, whose husband died five days after what she said was supposed to be a triple-bypass operation. "The doctor told me after the operation that when he got in there, more work had to be done. He told me he couldn't finish it all because my husband's heart wasn't strong enough."

"I'm so shaken by it," said Connie Coplan, wife of the Gaitherburg man who died after an operation in which the Navy charges that Billig tore his aorta and then improperly sewed the tear. "Yes, I did get an attorney."

Billig, the former head of heart and chest surgery at Bethesda, was referred for general court-martial -- the most serious of military court proceedings -- on June 19. He was charged with four counts of involuntary manslaughter and 22 counts of dereliction of duty after a two-month inquiry ordered by Rear Adm. William M. McDermott, head of the Naval Medical Command in Washington. That inquiry also found that Billig suffered from severe loss of sight in his right eye.

Neither Billig nor his attorney could be reached for comment yesterday. Both have refused previously to discuss the case.

Yesterday, the Navy increased the number of dereliction-of-duty charges to 28 based on the care of that many patients. The Navy alleges that Billig operated on those patients improperly, since he was not under the supervision of another doctor, from June to September 1983. Spokesmen said they did not know why the Navy added six more dereliction counts yesterday.

Three of the 28 patients are active-duty service personnel and the rest are dependents of military personnel or retirees, said Navy Lt. Stephen Pietropaoli. Pietropaoli was unable to identify which of the 28 are the three on active duty or to supply service affiliations.

If convicted of all four manslaughter and 28 dereliction charges, Billig could face a maximum penalty of dismissal from the Navy and 26 years of confinement at hard labor.

McDermott's formal inquiry was made after the physician was suspended last November by Bethesda Naval Hospital for what Navy officials said then were "questions about his competence."

Billig was commissioned in December 1982 and accepted a position in January 1983 as a heart and chest surgeon at Bethesda. According to documents obtained by The Washington Post, Billig was recommended to practice at Bethesda after a recruiter in Pittsburgh discounted correspondence from a New Jersey hospital that raised serious questions about his competence in 1980.

Administrators at that hospital, Monmouth Medical Center in Long Branch, have told The Washington Post that there is only one piece of written correspondence from the recruiter regarding the hospital's concerns. According to New Jersey court papers, the hospital had asked Billig to leave after a peer review team had said he lacked good surgical judgment, proper motivation, competence and honesty.

Billig later retired his New Jersey medical license, and no formal investigation was made by the state licensing board.

Billig was appointed to the heart and chest unit at Bethesda although he had not practiced heart surgery for about five years, according to one Naval report. He agreed to six months of retraining, that report said.