Heart With No Beat Offers Hope Of New Lease On Life by CARRIE FEIBEL

http://www.npr.org/2011/06/13/137029208/heart-with-no-beat-offers-hope-of-new-lease-on-life?sc=fb&cc=fp

June 13, 2011 from KUHF

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."

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.

"He wanted to live, and we didn't want to lose him," she says. "You never know how much time you have, but it was worth it."

Lewis worked for the city of Houston, helping to maintain the city's vast system of wastewater pumps.

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"I listened and it was a hum, which was amazing," Linda Lewis says. "He didn't have a pulse."

The doctors say the continuous-flow pump should last longer than other artificial hearts and cause fewer problems. That's because each side has just one moving part: the constantly whirling rotor.

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However, the only reason blood must be pumped rhythmically instead of continuously is the heart tissue itself.

"The pulsatility of the flow is essential for the heart, because it can only get nourishment in between heartbeats," Cohn says. "If you remove that from the system, none of the other organs seem to care much."

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After the implant, Craig Lewis woke up and recovered somewhat. He could speak and sit up in a chair.

But then he began to fade as the disease attacked his liver and kidneys.

"Amyloidosis is horrible," Linda Lewis says. "I could see the other organs were not cooperating."

Craig Lewis lived for more than a month with the pulseless heart. He died in April, due to the underlying disease. His doctors say the pumps themselves worked flawlessly.

"We knew if it wasn't a success for Craig, if they could get data that would help them, if it helps the next person, then you did good," Linda Lewis says.

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