. >> reporter: in one case recently, a 16-year-old high school basketball player from michigan, wes leonard, collapsed and died on the court just moments after hitting a game-winning shot. his cause of death? an enlarged heart. while there are only 50 to 100 of these cases in the u.s. every year, deaths like leonard's have sparked calls to get all high school athletes screened for possible heart defects. >> i feel like whenever you hit puberty, you should be getting tested. that's when they said it hit me. >> reporter: but this doctor who is a pediatric cardiologist believes screening is a waste of time and money. she says giving teens the standard test for heart defects would cost americans $2 billion a year. and those tests, she says, aren't very accurate. >> there's about a 10% false positive risk. >> reporter: she says a false positive could lead to further unnecessary testing. instead, parents and children should watch for key symptoms including fainting, chest pain while exercising and seizures. parents should keep track of the family history since many of these conditions are genetic