California ? Using electrocardiograms to test the hearts of young athletes before they participate in sports could be a cost-effective way to reduce sudden deaths, a Stanford University study concludes.

Questions about what type of pre-screening to require have drawn heightened interest since two seemingly healthy high school students from the San Francisco Bay Area suddenly collapsed during basketball games earlier this year.

One student died. The other was hospitalized and later released with a diagnosis of an electrical abnormality in his heart.

The California Interscholastic Federation, which oversees high school sports, requires all students to have a physical exam, including providing a family health history, before participating. That is the extent of screening for most students.

EKGs can detect signs of hypertrophic cardiomyopathy, a genetic defect that causes thickening of the heart muscle and can lead to dangerous heart rhythms that can stop the organ. Nationally, it is estimated that one in 500 people have this condition, a common cause of sudden deaths in young athletes.

But many experts consider routine EKG screening too expensive, especially since sudden deaths remain rare, involving fewer than 100 young athletes each year in the United States.