An Indianapolis family that lost their teenage son to an undiagnosed heart condition is embarking on a mission to warn other parents of the often hidden risk.Sudden cardiac death among young people is often associated with student athletes, 6News' Stacia Matthews reported.But Ryan Noll, 15, an aspiring artist from Pendleton, succumbed to the condition while visiting his mom and stepfather on Indianapolis' south side in July."When we left, he was perfectly fine. He hugged me and said, 'I love you mom, see you in a little bit,'" said Ryan's mom, Denise Sullivan.But when the couple returned home less than 30 minutes later, the family dog signaled trouble behind a closed bathroom door."I had to kick the door in to get to him," said Ryan's stepfather, Mike Sullivan. "He was already gone when we opened the door."Doctors later determined that the Pendleton Height High School freshman harbored a serious underlying condition called hypertrophic cardiomyopathy, or HCM, a congenital abnormal thickening of the heart wall."As the heart develops more and more thickness, it obstructs the blood flow to the coronary arteries and they have high risks of developing lethal cardiac rhythms, called arterial fibrillation, and death," said Dr. Randall Caldwell, director of pediatric cardiology at Riley Hospital for Children.Ryan's family said they never knew of his heart condition, and that the teen had never shown any symptoms.Caldwell said fainting spells, shortness of breath or chest pain should trigger a doctor's evaluation. Both check ups and electrocardiograms, or EKG's, can confirm trouble.Doctors also recommend an EKG for student athletes and for children with a family history of sudden cardiac arrest or sudden unexplained death.The procedure typically costs between $88 and $100, an investment Ryan's father said is worth making."It is not that much to do a quick scan, because the odds are there that it could happen," said Bryan Noll.Ryan's siblings are being tested for the heart condition.If they are diagnosed with HCM, they could be prescribed medication. If the condition is serious, an implantable defibrillator will be required to jump start the heart back into normal rhythm.Denise Sullivan said she is in the process of starting the Ryan C. Noll Foundation for Pediatric Heart Testing in an effort to raise awareness and potentially save lives.