A few years ago, Katrina Sellens — 14 and hungry for Thanksgiving leftovers — stood there in a familiar spot: Surveying the fridge for something to eat. What happened next was also recognizable to Katrina and her family. She passed out. Her fainting started when she was 7. By that point, she'd lived with the spells for half of her life. Still, Katrina had always been 'very, very active,' said her mother Maria. Roller skating and tennis, horseback riding and camping. A happy kid. Regular as her fainting had become, this time was different. Very different. 'I was so tired, 24/7,' Katrina said. 'It really hit when I was 14 years old.' How to Help a Kid With Heart Failure She found herself unable to walk 10 feet without becoming completely exhausted, struggling to catch her breath. Though she'd never been diagnosed with heart issues, her doctors identified progressing heart failure. It advanced quickly, her weakened heart struggling to pump blood adequately to meet her body's needs. What they thought was a respiratory infection was something much more serious. Doctors told Maria: 'That's not pneumonia. That's fluid buildup because her heart's not working right.'