Robert "Pete" Kenyon, 63, who holds the U.S. record for days lived with a temporary heart assist device, has received a human heart transplant at Yale-New Haven Hospital.

The transplant occurred only days after doctors replaced Kenyon's original Novacor, which was showing signs of wear.

Kenyon set the U.S. record in August, when he passed the three-year mark with a left ventricular assist device, which supports the workload of the heart in patients awaiting a transplant.

Kenyon said he can't get over how quiet his new heart is, after hearing the clip-clop of the Novacor for more than three years.

"To me, it's a miracle," he said.