NEW HAVEN, Conn. -- Pete Kenyon cuts a dapper figure, with his jaunty bow tie, striped shirt and navy blazer.

One hardly notices a black bag, slung casually over his shoulder, or a muffled clip-clop sound that accompanies him wherever he goes.

The bag holds the key to his life: the computer and batteries that keep his artificial heart beating inside his chest.

Kenyon, 63, has been living with an artificial heart for three years this week -- longer than anyone else in the United States, his doctors and the inventor of his Novacor heart device said Thursday. An Italian man has been using one for about four years.

Kenyon, of Darien, is waiting to get a heart transplant, but his blood type and tall stature -- about 6 feet -- have made most donor hearts a poor fit.

Ironically, because the artificial heart has functioned so well, he is healthier than many other heart patients and lower on the transplant priority list.

"I wait my turn, and in the meantime, the beat goes on," Kenyon said.

The first recipient of an artificial heart, Barney Clark, a Seattle-area dentist, lived 112 days after receiving a Jarvik-7 in 1982. Before Kenyon, the longest living recipient of an artificial heart was William Schroeder of Jasper, Ind. Schroeder lived with the heart for 620 days before he died in 1986.

Five weeks ago, doctors at Jewish Hospital in Louisville, Ky., implanted the first self-contained, mechanical heart into a patient. The patient had been given only 30 days to live, but doctors say he has regained strength and may one day be able to go home.

The device implanted into Kenyon on Aug. 11, 1998, is a simple pump with only two moving parts. It replaces the left ventricle of the heart -- the powerhouse that does most of the heart's pumping.

The patient's natural heart is left in place to tell the mechanical heart what to do. The pump uses an electric motor to contract in sync with the natural heart. About two feet of power cable travel from the device under the skin to the battery pack.

"The pump essentially takes over the workload the native heart cannot provide," said Novacor's inventor, Dr. Peer Portner, a professor at Stanford University. About 1,200 people worldwide have used a Novacor.

The Novacor has run for about five years in lab tests, but like all machines, it eventually will need to be replaced in Kenyon's body unless a real heart is found, Portner said.

Kenyon, whose device was implanted at Yale-New Haven Hospital, delights in telling stories of the lighter side of life with an artificial heart.

At movies and concerts, people have asked him to turn down or turn off the mechanical clip-clop sound the Novacor makes as it vibrates in his chest.

"I told them no," Kenyon said with a laugh.

He has had a close call with the heart's batteries, said his wife, Kathy Kenyon.

Once, they were stuck in traffic on Interstate 95 for two hours. They called the state police, who helped them find back roads to their home. Five minutes after arriving, the battery beeped that it was out of power, she said.

Each battery is good for about 3 1/2 hours. Kenyon brings extra batteries with him when he goes shopping or to his office.

Kenyon, who is a reinsurance broker, also works from home and maintains a fairly normal lifestyle.

While his exercise is limited to climbing stairs and walking, Kenyon said he gives the artificial heart a workout by chasing his three grandchildren and eating spicy food.

"It hasn't been discouraging or negative in any way," he said.

Doctors credit Kathy Kenyon, a nurse, for taking care to make sure the device does not lead to serious infections.