MIAMI -

It's senior year for David Martinez. He's been playing football since he was 6 years old. Watching him practice, you would never guess that David was recently diagnosed with a potentially deadly heart condition.

"I've always been healthy," David told Local 10's Kristi Krueger. "I was shocked when I heard the news."

David was living with something called Wolf-Parkinson-White Syndrome. WPW can cause the heart to skip beats, or even stop altogether.

"The heart is a muscle, but it is also electrical with wiring," said Miami Children's Hospital cardiologist Dr. Steven Fishberger. "With WPW there is an extra circuit that can cause heart rhythm problems."

Left untreated, David could have become the victim of sudden cardiac death.

Every three days, another student athlete dies from sudden cardiac death in the United States. But a simple test can save lives.

That's why, for more than a year, Miami Children's Hospital has been offering free EKG screenings for all student athletes. It isn't a mandatory test, but David's dad is glad he signed up for it.

"Two days later, we got the call from Miami Children's Hospital that David has a condition they found on the EKG and that surgery was the only solution for it," said Daniel Martinez, David's father.

"These are mostly medical issues we can treat, so that's really the good news," said MCH Cardiac ICU Dir. Dr. Anthony Rossi.

David underwent a quick procedure and is now completely healthy. He's working with his dad off the field and hoping to one day be a construction manager.

David is among a handful of South Florida kids whose lives may have been saved by this free test.

Doctors say its a needle in a haystack kind of job and they evaluate a lot of EKGs to find one that is abnormal.

For more information on receiving a free screening, or to schedule an appointment, call the Heart Program at MCH at 855-MCH-EKGS -- 855-624-3547.