HOUSTON -- Key Middle School students were warned Thursday about a killer among young athletes: sudden cardiac arrest, KPRC Local 2 reported.

Adrian Longoria, 17, knows all to well about hearts stopping. His stopped last year while in gym class. He said that before that incident, he never felt any pain or had any problems with his heart.

"There's no real symptoms that you can feel. It all just came out of nowhere," said Longoria.

Houston Early Age Risk Testing and Screening is a study and program designed to detect any abnormal heart conditions that can cause the heart to arrest. Memorial Hermann Hospital , The University of Texas Medical School at Houston and the Houston Rockets are involved in the free, four-step program that includes a self-administered questionnaire and cardiovascular physical exam of sixth-grade students athletes or non-athletes to detect potential heart problems

"This is achieved by identifying children at risk," Dr. John Higgins said. "That includes history, EKG, sonogram, all during a 15-minute check up."

Houston Rockets center Dikembe Mutombo said early detection is key to living a happy and healthy life.

"We don't want you to just sit at home," Mutombo said. "We want you to be active. Heart disease is the No. 1 killer in America."