"It's enough to augment the failing heart and keep blood pressure maintained," said O'Neill. "It really can provide very effective support in people that have almost no heart function."
Dr. Faisal Khan, Zeoli's heart surgeon at St. Elizabeth's, likens use of the device to regulating traffic; by pushing some of the blood through itself, Khan explains, the Impella is enabling the heart to maintain blood flow while pumping less.
"When it's pumping against less traffic, or less pressure, it can get blood around easier," he said, noting that by allowing the heart to work less temporarily, it may hasten recovery.
Khan said the device can do roughly half of the heart's work.
So far, he has used the device on two patients, Zeoli and another patient who needed it after a heart attack.
"We're excited about the potential they will provide to us to extend the care of patients who are very sick," said Khan.
In June, the Impella was cleared for marketing by the Food and Drug Administration, according to agency spokeswoman Karen Riley.
She said the current trial is not part of the regulatory process, which the Impella has already cleared. She explained that some companies run further trials for other purposes, such as insurance clearances or marketing.
Researchers involved hope that the Impella will replace the two main devices currently in use. The first and more common device, known as a balloon pump, displaces blood by its expansion and contraction, while the other, known as a TandemHeart, involves making a hole from one side of the heart to the other.
While he remains optimistic that the device will ultimately replace others, O'Neill said that the current trial will likely take another year and that only then will most consider adopting use of the Impella.
"Most American cardiologists want to wait to see some proof that it's actually better than a balloon pump," he said. "I think that people are going to wait for a while to see what happens with this trial before they decide if they're going to use it or not."
For Zeoli, the Impella was beneficial, although she still requires more treatment. She has chosen to be optimistic about where she is now.
"I'm fine and I'm blessed," she said.
In September or October, Zeoli will need to return to have more stents put in; ultimately she will have 15 of them in her body.
"I'll be bionic," she said.