MINNEAPOLIS (AP) _ A 28-year-old North Dakota mother of two was in critical condition today after receiving an artificial heart at Abbott Northwestern Hospital, a hospital spokeswoman said.

Nicole Christoffersen, a housewife from Minot, underwent the implant surgery Tuesday night, nearly a month after Mary Lund, the first woman to receive an artificial heart, who later received a human heart, died at the hospital.

Mary Small, public relations official with the hospital, said surgery began around 6 p.m. CST Tuesday and ended at 11:30 p.m. CST. Christoffersen was in criticial condition in the intensive care unit this morning, she said.

Christoffersen received a mini Jarvik-7 artificial heart ''similar'' to the one implanted in Lund, a 40-year-old nursing home secretary from Kensington, Minn., Small said.

The mechanical pump ''is a temporary measure until a human heart becomes available,'' Small said. ''Her life was threatened and so, as a result, an artificial heart was implanted as a bridge to transplant. It's intended as a temporary device, so that the woman can regain her health to the point where she would be appropriate as a transplant candidate.''

At a news conference today, Dr. Marc Pritzker, a cardiologist with the hospital, said Christoffersen had been suffering from acute congestive heart failure as a result of myocarditis, an inflammation of heart tissue.

Christoffersen was fully conscious before the operation and made the decision herself to go ahead with the implant after discussing it with her husband, Dean, and other members of her family, Pritzker said. She has two sons, ages 2 and 4.

Christoffersen was in somewhat more stable condition than Lund when she underwent the transplant, Pritzker said.

Lund, 40, of Kensington, died Oct. 14 as an apparent result of the viral infection that had caused her own heart to fail, doctors said.

She received the mini-Jarvik on Dec. 18, one day after being hospitalized with her own heart severely damaged by a sudden viral infection. She previously had no history of heart trouble.

On Jan. 31, Mrs. Lund received the heart of a 14-year-old girl who died after suffering an epileptic seizure. The transplant was successful, but Mrs. Lund's vital organs were apparently seriously weakened by the original infection, doctors said.

Twenty-three people have received artificial hearts as a bridge to human heart transplants, Dr. Lyle Joyce, a surgeon with the Minneapolis Heart Institute who led the team that implanted Mrs. Lund's artificial heart, said at the time of her death.

The second woman to receive an artificial heart, Bernadette Chayrez, died Oct. 11 in Phoenix.