Lea en español After Cecilia Galeana gave birth to her second child, Elias Soto, a pediatrician performed standard newborn tests. Listening to his heart, the doctor heard a whooshing and swishing sound. Elias had a heart murmur.

It could be hypertrophic cardiomyopathy, or HCM, the doctor said. It's a condition in which abnormally thick heart muscle makes it hard for the heart to pump blood. Cecilia and her husband, Rafael Soto, went home with a pediatric cardiologist referral.

For the next few months, the couple settled into life with two kids at home in Ontario, California. Elias met his big sister, Zulay, who was 3. At the cardiologist appointment, 4-month-old Elias had an electrocardiogram, or EKG, to measure the electrical signals in his heart and a heart ultrasound, known as an echocardiogram.

Results confirmed the pediatrician's suspicion: Elias had HCM. It's the most common cause of sudden cardiac death in people under age 35. Cecilia and Rafael panicked.

Before they had Elias, they'd never heard of the disease. They had a long list of questions: How did he get it? When? Why? "We took it day by day, learning off of the doctors and not so much the internet," Cecilia said. Elias' cardiologist referred the family to Dr.

Jennifer Su, a cardiologist and co-director of the Cardiogenomics Program at Children's Hospital Los Angeles Heart Institute. The treatment plan was straightforward. Doctors would closely monitor Elias to make sure his heart continued to function properl.