When patients whose hearts were too weak to circulate blood independently were given their first hope for survival in the form of a mechanical pump, the New York Times hailed it as “a step towards a totally artificial heart.”

Less than two decades after the Novacor LVAS pump was introduced, doctors at Yale-New Haven Hospital have one-upped the newspaper’s prediction. Three weeks after implantation, physicians saw marked improvement in cardiac function and removed the pump from 45-year-old Laurie Bartow, leaving her heart stable and working on its own. This was the first time such a procedure has been performed in the United States. Bartow had been diagnosed with viral cardiomyopathy, a disease that slowly destroys muscle in the heart wall and is usually fatal.

The survival rate of patients like Bartow with artificial pumps is 25 percent after two years, compared to 10 percent without a cardiac assist device.

“We are talking about very sick patients, and their life expectancy is essentially nil without some kind of assistance,” said John Elefteriades, the lead surgeon on the operation and chief of cardiovascular surgery at Yale-New Haven. “We took a chance, and we held our breath.”

Bartow is now recovering at home. Her heart strength is almost normal, though she is still on medication, and she is looking forward to sending her children back to school, Yale-New Haven transplant coordinator Noreen Gorham said.

In the next month, Bartow will return to the hospital for two additional surgeries. One will attempt to repair a small hole in Bartow’s heart wall between her two ventricles, Gorham said. The other, Elefteriades said, will remove a small piece of hardware located at the tip of Bartow’s heart that was left to prevent the pump removal surgery from being too lengthy.

The Novacor LVAS completely replaces the heart’s left ventricle, the powerful pumping chamber that transmits oxygen-rich blood from the heart to all bodily organs. An electromagnet in the device pushes a piston, and blood is forced throughout the body by a set of tiny bellows.

The device was FDA-approved to stabilize a patient while awaiting a transplant, which could take years. Yale-New Haven is also participating in a study to determine if the device could be used as a therapy that patients could live with permanently.

With the removal surgery’s success, a new paradigm is emerging, said Robert Towns, a spokesman for the American Heart Association.

“Instead of looking at bridges to survival, we’re looking at bridges to full recovery — devices that allow the patient to recover normal heart function,” he said.

But Bartow’s surgery is “an anecdotal story right now,” Towns said, and its real significance is as a real-world test case for removal of the device.

“Do I think it is something that will happen again? If the opportunity presents itself,” said Peggy Allman, the spokeswoman for Novacor’s manufacturer. “Was it something we were planning on? Not really.”

The procedure has been performed less than 40 times worldwide and only twice on patients with Bartow’s condition.

Elefteriades called the surgery “extremely risky,” but pointed out that living with an artificial cardiac assist has its own set of risks.

Though such a patient can in theory live almost indefinitely, infections can enter the body via the device’s driveline, which pierces the skin, and blood clots that form on the mechanical device can have grave consequences if they travel to a patient’s brain.