When she's at home, Kyah can plug herself into the wall. If there's a power outage, the city has a backup generator on standby, in case her four back-up batteries run out. And if she's in a car, she can use an adapter to get power from the cigarette lighter.
The artificial heart, called a Heartware Ventricular System, was FDA-approved for use in kids Nov. 20, 2012 -- nine days after Kyah became one of a handful of American kids using the pump as a "bridge" to a transplant. Because it's continuous flow, meaning it doesn't contract and relax like a real heart, Kyah hears a constant hum instead of having a pulse.
"I can feel it inside, vibrating," she said. "It's very noisy."
Kyah, who wore skinny jeans and a loose gray t-shirt with a heart on the chest for her first day back at school, doesn't love the black bag. But her mom hopes to change that.
"We talked about bedazzling the bag," said Danielle DeSimone. "I'm sure we could do something."
But mother and daughter hope the bag and the device it powers are a very temporary fix.
"It's a little nerve-racking," Kyah said of the indefinite wait for a transplant. "I guess I'll just stay positive."