Austria ? Cardiac problems like an abnormal heartbeat are exacerbated by rigorous exercise in a way that can be fatal in athletes, and regular testing for the problem could save lives, doctors at a heart conference said Sunday.

Italy is the only country that mandates heart screening of all its professional athletes, Dr. Domenico Corrado of the University of Padua said at the European Society for Cardiology meeting in Vienna.

Since 1981, Italian authorities have run heart checks on all competing athletes. The incidence of sudden, fatal heart attacks has dropped from four cases per 100,000 to 0.4 case per 100,000.

Without testing, athletes genetically predisposed to having an irregular heartbeat might not be aware of their condition until it’s too late, doctors said. Adrenaline produced during exercise may overstimulate the heart, causing it to essentially short-circuit.

“Sport acts as a trigger,” Corrado said in research presented at the meeting.