Monday, June 13, 2011

Living Without a Pulse

by Carrie Feibel

The search for the perfect artificial heart seems never-ending. After decades of trial and error, surgeons remain stymied in their quest for a machine that does not wear out, break down or cause clots and infections.

But Dr. Billy Cohn and Dr. Bud Frazier at the Texas Heart Institute say they have developed a machine that could avoid all that with simple whirling rotors — which means people may soon get a heart that has no beat.

Inside the institute's animal research laboratory is an 8-month-old calf with a soft brown coat named Abigail. Cohn and Frazier removed Abigail's heart and replaced it with two centrifugal pumps.

"If you listened to her chest with a stethoscope, you wouldn't hear a heartbeat," says Cohn. "If you examined her arteries, there's no pulse. If you hooked her up to an EKG, she'd be flat-lined."

The pumps spin Abigail's blood and move it through her body.

"By every metric we have to analyze patients, she's not living," Cohn says. "But here you can see she's a vigorous, happy, playful calf licking my hand."

Human Trials

In March, after practicing on 38 calves, Cohn and Frazier felt confident enough to try their device on a human patient. They chose Craig Lewis, a 55-year-old who was dying from amyloidosis, which causes a buildup of abnormal proteins. The proteins clog the organs so much that they stop working.

In Lewis' case, his heart became so damaged, doctors said he had about 12 hours left to live.

His wife, Linda, said they should try the artificial heart.

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