Several prominent heart surgeons yesterday supported expanding use of the artificial heart as a temporary measure for patients awaiting human heart transplants, but most expressed serious concerns about continuing its experimental use in humans as a permanent heart replacement.

The strongest reaction came from Dr. Christiaan Barnard, the South African surgeon who made history in 1967 with the first human heart transplant. He called upon Dr. Robert K. Jarvik, the inventor of the Jarvik-7 artificial heart, and researchers using that device to forgo additional permanent-implantation attempts in humans.

"I see very little place for the mechanical device as an alternative to the human heart" on a permanent basis, Barnard said. In addition to knowing when to move out of the laboratory to test new ideas on patients, he said, researchers "must also know when to move back to the laboratory" if problems develop.

Barnard and others expressed concern about the frequency of complications in the heart implants tried to date, especially the strokes suffered by four of the seven Jarvik-7 patients and bleeding problems experienced by most of them.

Jarvik said his company, Symbion Inc., is working on modifying the Jarvik-7 to minimize the blood-clotting problems. But he defended the experimental effort as an "evolutionary" one in which the knowledge gained from one patient is utilized in treating the next.

Dr. William C. DeVries, who has performed four permanent artificial-heart implants -- including the first such implant, on Seattle dentist Barney B. Clark in 1982 -- said he will proceed with his experimental program and try another implant as soon as a patient becomes available at the Humana Heart Institute in Louisville.

"I'm going to keep going," he said. DeVries has federal permission for three more permanent implants -- the only U.S. doctor given such approval by the Food and Drug Administration.

While DeVries has vowed to proceed, Dr. Bjarne Semb of the Karolinska Institute in Stockholm, the only other surgeon who has done a permanent artificial-heart implant, said he will await design modifications in the Jarvik-7 before attempting another human implant.

The doctors spoke here at a conference, sponsored by the Foundation for American Communications and the Gannett Foundation, that brought together a small group of top medical experts and journalists to examine the medical and ethical issues raised by human heart replacement, both implants and transplants.

Although heart transplants are increasingly successful and more are being done -- more than 400 last year -- there is a shortage of donor organs and many patients die before a donor heart can be located. The temporary use of artificial hearts for dying patients awaiting transplants is expanding rapidly.

In the past week, two Pennsylvania institutions have implanted artificial hearts temporarily, one a Jarvik-7 and the other the new Penn State heart. The University of Arizona has made two temporary attempts this year -- an unauthorized and unsuccessful implant in March and a nine-day Jarvik-7 implant in August in Michael Drummond, who got a human heart transplant and continues to recuperate.

The University of Arizona's Dr. Jack Copeland and Dr. Denton A. Cooley, the Texas Heart Institute surgeon who did the first two temporary artificial-heart implants (in 1969 and 1981), supported the temporary use of artificial hearts, but not permanent implants.

Of the five men who have had permanent implants, three remain alive. William J. Schroeder has had two serious strokes since his implant at Humana 11 months ago, but is no longer in the hospital. Murray P. Haydon, who had an implant at Humana in February, also suffered a minor stroke and remains hospitalized with breathing problems. Swedish patient Leif Stenberg was mobile and active before he, too, suffered a stroke; he remains hospitalized.