so. >> jason an stacy have had no time to recover from sierra's transplant. ge before this next crisis. they are emotionally exhausted. >> give him a good last kiss. >> be brave. >> surgeonings have warned jason and stacy that there is a chance gauge could come out of surgery on an artificial heart pump similar to the one lindsey was on. it would mean he could not leave the hospital until a donor heart could be found. >> to think he walked in here a happy little kid with this little bear and to think he might come out or we could get the call any second now that they had to put him on a heart device, it's pretty hard. >> but gain's surgery goes well. no artificial heart pump necessary. finally, they get to go home. the hardware inside gauge's tiny chest regulates the boat of his heart. but he can't stop the pro greg which is happening must faster than anyone anticipated. he had always shaken his head, no, when his parents told him he needed a transplant. one night, tired and having thrown up, gain few it was time. >> he goes, you're right, mom, i'm like i'm ri

and the doctors gave jason and stacy the news. without an almost immediate heart transplant, their daughter would die. when we say it was a nightmare, it was the worst time of our life. bar none, it was the worst three weeks of my life. >> the wait for a donor heart for a child can be months. it was time sierra didn't have. >> to say there's a time when you've shed every tear you can shed and go home at night completely exhausted, physically, emotionally. we had hit that point. >> we told as many people as we could, please pray for our little child tonight. 1:30 in the morning, we get a phone call. and i thought, that's it. >> i thought it was the worst. and the doctors called and they said, we have a heart available for sierra. and i was like, are you serious? >> the binghams' prayers were answered. the next afternoon, sierra received her new heart. boy. in the world of heart transplants, size matters more than age. sierra's new heart would grow as she did. >> when it came, it just -- we knew everything was going to be fine. there was just

jason bingham worked at his father's accounting business. stacy was an obstetrics nurse at a nearby hospital. this was the home the binghams loved and where they imagined they would raise their kids and live for the rest of their lives. >> hi! >> hi! easter morning. we're really late for church. >> it takes each one of them to make us a family. you have sierra, compassionate and loving, megan, who is lindsay has been our little jabber jaws. she makes sure everyone stays in line and then hunter, who is just a happy-go-lucky 5-year-old. >> oh, yeah. >> full of energy. >> just full of energy and life. kind of the family clown. >> we love it. the life of the party. >> but parties don't last forever because the bingham family was about to become a terrifying medical mystery, one of the strangest, most off-the-chart, unlikely story we ever heard of. it began in 2006 when sierra, their eldest, threw up for several days. her parents took her to the doctor. >> the doctor came in and said we have one of three things, it cardiomyopathy. >> they gave her a cardio ca