The NCAA has released guidelines on electrocardiograms to prevent sudden cardiac death in student-athletes, but stopped short, as expected, of recommending the heart test for all college athletes.

The announcement comes nearly a year after the NCAA’s chief medical officer, Brian Hainline, M.D., told American Heart Association News that schools would not be required to screen with ECGs the more than 460,000 student-athletes across the country.

Hainline defended that decision again Friday, saying few schools have the resources to conduct such testing and even fewer doctors have the expertise to interpret ECGs in elite athletes.

“To mandate [ECG screening] would be to mandate something where the knowledge base across the country is exceptionally uneven,” Hainline said.

But schools conducting ECGs, a test that measures the heart’s electrical activity to check for a number of heart problems, should now follow certain rules, according to the new recommendations published in the Journal of the American College of Cardiology. Only trained doctors who can differentiate a benign change from a true heart disorder should be conducting and interpreting the ECGs, and student-athletes should understand the reasons for the test and its possible risks and benefits.

“If we do [ECG] screening, this is the best way to do it,” Hainline said.

The NCAA does not know how many schools nationwide are currently screening athletes with ECGs, but Hainline estimates it is being done in about 40 percent of Division I power conferences.

Research suggests four to nine of the NCAA’s nearly half-million student-athletes die from sudden cardiac arrest each year.

Currently, ECG screening is required for many professional athletes, but not for those in high school or college. Recent legislative efforts to mandate ECG screenings for public high school athletes have failed in states such as Texas.

The new recommendations also endorse a standardized physical exam and questionnaire on medical and family history, such as the 14-part evaluation recommended by the AHA and ACC. Both organizations oppose mandatory mass ECG screening for young athletes.

The NCAA already requires student-athletes to undergo a medical evaluation before participating in a sport. But the new guidance says the evaluation must now be conducted or reviewed by a team physician rather than any doctor.

Universities should also have an emergency action plan for cardiac arrests that occur during a game or practice. The plan should be rehearsed at least once a year and include training expected responders, setting up emergency communications protocols and having easy access to an automated external defibrillator, or AED, a portable device that detects when someone is in cardiac arrest and then shocks the heart back to a normal rhythm.

Even though NCAA schools will not be required to follow the new recommendations, Hainline expects all will. Not doing so, he said, could rouse critics if a student died from cardiac arrest.

Member schools are being urged to implement the new recommendations by the 2016-2017 school year, Hainline said.

Development of the new guidelines began in 2014, when the NCAA convened a task force of 29 doctors and athletic trainers from national sports and medical associations, including the American College of Sports Medicine, American Academy of Pediatrics and the AHA.