For 5 weeks, the tiny Impella kept Katrina Penney's failed heart pumping while a second heart transplant was secured.

The world's smallest heart pump helped save a Children's Hospital of Philadelphia patient's life. Now that it's been ...

"It does all the work for your heart," Katrina Penney, 21, said. "It did save my life, 100%." It is the Impella 5.5 – the world's smallest heart pump that helps blood circulate. Penney was born ...