A tiny pair of umbrellas unfurled inside the heart can permanently repair dangerous, leaky holes that result from birth defects and can eliminate the need for surgery, doctors report.

The umbrellas are threaded into the heart through a skinny tube, or catheter. They are being used experimentally to fix atrial septal defects, which are found in 5,000 to 10,000 Americans annually.Left unrepaired, blood spurts through the hole from one side of the heart to the other, eventually leading to heart failure, irregular heartbeat and death. The defect is often diagnosed during childhood because of the unusual noise, or murmur, made by blood rushing through the hole.

Until now, the only way to fix the defect and avoid dangerous complications later in life was to perform open heart surgery and sew up the hole.

The new device, which is much cheaper than surgery, was developed by Dr. James E. Lock of Children's Hospital in Boston.

He described its experimental use on 200 patients during a conference Thursday sponsored by the American Medical Association.

"I think it is extraordinarily useful," commented Dr. Martin O'Laughlin, who has tested it at Texas Children's Hospital in Houston. "The advantages include no scar, no open heart surgery, no general anesthesia and no surgeons' fees."

Lock said the device, known as a Bard clam shell septal umbrella, will probably be submitted to the Food and Drug Administration for approval for routine use next month. He expected it to be widely available in two to three years.

"There is accumulating evidence that catheter closure is likely to be safe and effective in about half of all patients" with the heart defect, Lock said.

Those who cannot receive it are largely those whose holes are too big to be covered by the twin umbrellas.