Some Olympic athletes could be at risk while training and competing because of heart defects or dysfunction that they may not even know about, Italian researchers say.
About 4 percent of the Italian athletes studied over a 10-year period with MRI and CT scans as well as electrocardiograms (ECG) had cardiovascular disorders - a higher proportion than researchers expected to find.
"Even though it's a small percentage with abnormalities, the implications can be huge," said lead author Dr. Antonio Pelliccia, scientific director of the Institute of Sports Medicine of the Italian National Olympic Committee in Rome. "Athletes may be healthy, but they may not be safe from certain risks such as sudden death syndrome."
Pelliccia and colleagues looked at screening results for more than 2,300 athletes during the period between the 2004 Olympic Games in Athens and the 2014 games in Sochi, Russia. As part of the heart screening process, the Italian medical team incorporates medical history, a physical exam, an ECG and an echocardiogram.
They found that 92 athletes had abnormal results, including inherited heart problems, coronary artery disease, hypertension, electrical diseases such as atrial fibrillation and tachycardias. The research team didn't see a major difference based on the type of sport played.
Overall, nine of 92 athletes with cardiac abnormalities were disqualified from competitive sport and 17 had temporary restrictions until the abnormalities were resolved. For many of the athletes, however, these abnormalities don't show any symptoms and may not affect performance either, the study authors write in the British Journal of Sports Medicine.
About 60 percent had valvular problems, which didn't prompt conversations about disqualification for future sport participation, they write.
"Not all abnormalities are diseases, and not all are concerning," Pelliccia said. "Valvular abnormalities in young people, for instance, are treatable and don't represent a real limitation."
Since 2009, the Italian National Olympic Committee has required periodic evaluation of elite athletes. Few international groups - only the Federation Internationale de Football Association (FIFA) and Union Cycliste Internationale (UCI) - require screenings, the authors note. In fact, no medical evaluation was universally required for athletes until the 2016 Rio de Janeiro Summer Olympic Games, they write.
Italy's screening process, particularly with mandated electrocardiograms, has been among the most vigorous in recent years, said Dr. Douglas Zipes, a professor of cardiology at Indiana University School of Medicine in Indianapolis, who wasn't involved with the study.
"Their required ECGs have reduced sudden deaths and encouraged the rest of the world to follow suit," Zipes told Reuters Health. "But the rest of the world still asks questions about the benefits, costs and effectiveness of requiring it."
The study also points out false negatives from the screenings during the decade, said Dr. Kimberly Harmon, head football physician at the University of Washington in Seattle, who wasn't involved with the study. Many of the abnormalities may have been present at previous screenings but didn't lead to a diagnosis because of inconclusive results or incorrect interpretation of the results.
"Screening for these conditions is important to prevent sudden cardiac death," she told Reuters Health by email. "The currently recommended history and physical is unlikely to discover many of these conditions, so advanced screening may be required to detect them."
Despite concerns, sudden death in athletes is still quite rare, Zipes noted, with fewer than 100 sudden deaths occurring in U.S. athletes annually. That compares to more than 300,000 annual sudden deaths in the general U.S. population, according to a 2014 American Heart Association report.
"We make a big deal out of these deaths because of the emotional impact, especially among professional and Olympic athletes who represent the epitome of health," he said.
The study makes a statement about the potential for cardiovascular abnormalities in everyday athletes as well - but shouldn't cause alarm, he said.
"Exercise is beneficial, whether you achieve Olympic status or are a weekend warrior," Zipes said. "Ultimately, whatever you like to do, exercise is helpful for the heart."