BOSTON (Boston Globe) - Anyone in the same room with Art Corbett can hear the rhythmic "whoosh-whoosh” emanating from his body, a sound like someone pumping up a bicycle tire.

Corbett, who was near death last year from heart failure, only smiles at mention of the noise. It's the sound of an electric heart pump implanted in his body, run by batteries carried in a fleece vest. That noise is the sound of Corbett's rebirth.

“It's just been amazing, what this has done for me,” said Corbett, of Gorham, N.H., who had the pump implanted in October.

With far less publicity than the doomed artificial heart experiments of the 1980s, Corbett and hundreds of other terminally ill heart patients are entrusting their lives to mechanical pumps that assist their hearts rather than replace them.

For most patients, these pumps, known as Left Ventricular Assist Devices, or LVADs, are a temporary “bridge” to support them while they move up the waiting list for a donor human heart. In some cases, the heart recovers and the pump can be removed.

But for Corbett and a small but growing number of others, the pump is no bridge: It's “destination therapy,” the last miracle in medicine's black bag for them. It is a permanent implant.

The device is a major step toward an artificial heart: The latter would replace the natural organ, but the LVAD piggybacks on the patient's heart and takes over much of the pumping.

“We're starting a new era,” said Dr. William Dec, medical director of heart transplants at Massachusetts General Hospital in Boston. “Devices used in the short term as bridge-to-transplant are now being redesigned for long-term therapy.”

Some 2 million to 3 million Americans suffer from heart failure, meaning the heart can no longer pump enough blood. It's said that 40,000 or more annually could benefit from a human heart transplant, but the shortage of donor organs has imposed a ceiling of about 2,300 transplants a year, meaning that many people die waiting.

Among the proposed ways to fill the gap are artificial hearts and transplants from animals, but each faces significant hurdles: Artificial hearts are just entering human trials after a nearly 20-year break, while researchers have not found a way to implant animal hearts without serious risk of organ rejection.

By comparison, LVADs are here right now - 300 to 600 are implanted annually - and researchers have launched a nationwide test to see if they can be used as permanent, rather than temporary, treatment. About 120 patients, each diagnosed as having six months to live, have been randomly assigned either to receive an implanted pump or the best possible treatment with drugs for heart failure.

Not everyone takes well to the assist devices, which restrict the patient's movements and require elaborate plans in the event of a breakdown, including backup generators in case the electricity goes out at home.

But Corbett, an amiable retired minister from Gorham, N.H., is a good sport about the annoyances, especially the electric wire and air vent protruding from the skin of his side that has to be cleaned and bandaged scrupulously.

Every morning, his wife, June, dons a sterile gown and gloves to change the dressing: If infection got started on the electric wire, it could go directly to his heart.

However, patients won't have to contend with the wire in the newest, experimental LVADs. On Feb. 28, a heart failure patient received the first U.S. implant of a cordless pump called the LionHeart, at Penn State's Hershey Medical Center in Hershey, Pa. The power for the electric pump is transmitted through the patient's skin from a coil on the outside to one on the inside. The LionHeart, made by Arrow International of Reading, Pa., has also been given to 10 patients in Germany.

“We tell them we think this pump is good for two years,” said Dr. Benjamin Sun, director of heart transplantation at the Hershey medical center. “Possibly longer. Hopefully longer.”

All LVAD patients, however, need to carry batteries or plug into a power supply at night.

Wherever they go, the Corbetts carry a black bag filled with extra batteries, an illustrated manual for the heart, and a hand air pump that Corbett or his wife could attach to the heart's air vent to keep him alive if the device broke down. Corbett's wife dares not be far from him, even for half an hour: She's the expert on fixing the automated device should it fail. That's part of the deal.

“You have to commit yourself to it for the rest of your life,” she said, noting that it has limited her life as well as her husband's.

Another LVAD user, Tom Sapos, 57, of Stafford, Conn., has been living with his battery-powered device for six months - and he feels fine. Although he must stay near hospitals and he has to be plugged in at night, he can drive, take walks and ride his exercise bike.

Unlike Corbett, Sapos is waiting for a transplanted human heart. The pump was implanted in September, when Sapos was so weak that a human transplant operation was considered too risky. In what is a common occurrence, doctors say, Sapos has gained weight and strength and now is a better candidate for a transplant.

Corbett's age and other medical problems ruled out a transplant. Before LVADs, he would probably have died by now. Though there is no transplant in his future, Corbett is philosophical, even upbeat in the face of a daunting unknown: how long the mechanical partial heart will keep working.

“As long as this thing's working and going, I'm going to keep going, too.” he said. He expects the machine to last at least three or four years, “And I hope to go a little longer than that.”

But not everyone wants a pump - even when they know they will die without one.

“Patients feel very differently about how they approach the end of life,” said Dr. Lynne Warner Stevenson, a heart failure specialist. “We've found that a surprising number of patients do not want to go onto a mechanical device, even if they understand this may be the best chance of survival.”

Nevertheless, “There's no question we're hurtling toward major interventions with mechanical devices” for patients with severe heart failure, said Stevenson, a Harvard associate professor and head of the heart failure program at Brigham and Women's Hospital in Boston. But, she cautioned, the pumps are so new that they will only be used as permanent heart replacements in a small number of patients in the near future.

Corbett and hundreds of others who are using the pumps provide a preview of the next generation of artificial hearts - more powerful double pumps that will replace, not just assist, the organ. An artificial heart made by Abiomed of Danvers, Mass. has won U.S. Food and Drug Administration approval for a limited run of tests. Two Boston hospitals will participate.

Corbett's pump doesn't replace the heart. In some ways, this is an advantage: If the mechanical pump fails, his own heart, though weakened, might keep him alive until help came. People who need both pumping chambers, or ventricles, replaced need a total artificial heart.

The slightly built Corbett and his wife came down from New Hampshire recently for a regular checkup at Brigham and Women's. The surgeon who installed the pump, Dr. Gregory Couper, listened with a stethoscope and found nothing amiss. “You can't really hear much” from the patient's own heart and lungs because of the sound made by the heart pump.

Corbett pedaled an exercise bicycle to test his endurance, and had blood tests. His LVAD had a test, too. A nurse plugged it into a HeartMate monitor, like an auto hooked up to a computerized diagnostic machine. The readings would be sent to the company that makes the device, Thoratec Inc. of Woburn, Mass., formerly Thermo-Cardio Systems.

After the three hours of tests, which showed a slight improvement in his own heart, Corbett and his wife left Boston for home, an inseparable couple for the duration.

WHEN TO TRY AN ARTIFICIAL HEART

Although ventricular assist devices save lives, they won't work if both of the heart's ventricles, or pumping chambers, have been damaged. Those people need a total heart replacement - and there aren't nearly enough human donors to go around.

That's where the artificial heart comes in. Seventeen years after the tragic death of the last person to get an artificial heart, a new generation of researchers are ready to try again Earlier this year, the government gave Abiomed approval to try its new artificial heart in five patients as a treatment of last resort. Two of the five medical centers that will test the AbioCor devices are in Boston.

The AbioCor is designed to replace the heart and, unlike past artificial hearts, it will be fully implantable. Everything except for a battery-powered external energy source will be inside the body, doing away with the skin-piercing electrical line that most previous artificial hearts and ventricular assist devices required.

In Boston, surgeons at MassGeneral and Brigham and Women's will use their experience installing left ventricular assist devices to test the AbioCor. The other centers are the Texas Heart Institute in Houston, Hahnemann Hospital in Philadelphia and Jewish Heart Lung Hospital in Louisville, Ky.

The first implant hasn't been scheduled yet and probably won't take place until the summer or later.

Before the trials can begin, Abiomed must convince the U.S. Food and Drug Administration and local ethics review boards that its patient consent forms explain all the risks and don't put pressure on dying patients to sign up.

Copyright 2001 The Boston Globe. All rights reserved.