The tragedy of sudden cardiac death among athletes, when a seemingly healthy young person collapses and dies without warning, has prompted some European countries to mandate screening all athletes with electrocardiogram exams before sport participation.
But a new Stanford study, published today in the Journal of Pediatrics, suggests that a clean ECG exam may give athletes a false sense of security. The problem, the study found, is that pediatric cardiologists' accuracy at reading ECG exams is poor.
From a press release I wrote about the new research:
“An ECG doesn’t always pick up the abnormalities that may predispose someone to sudden cardiac death,” said Allison Hill, MD, the study’s first author. “And this exam can be difficult to interpret, even if the person reading the scan is a pediatric cardiologist.” Hill recently finished her pediatric residency at Packard Children’s Hospital and is now a pediatric cardiology fellow at Children’s Hospital Boston.
In the new study, published online July 14 in the Journal of Pediatrics, 53 members of the Western Society of Pediatric Cardiology were asked to interpret a set of 18 ECG exams, some from healthy athletes and some from those with heart defects. The physicians, who had an average of five to 15 years of experience in their field, accurately diagnosed the heart conditions only 67 percent of the time. They correctly permitted sport participation for healthy individuals 74 percent of the time, and correctly restricted sport participation for those with cardiac defects 81 percent of the time.
“As athletes’ hearts grow stronger, they undergo some changes that make it very difficult to tell: Is this a well-trained athlete or does this person have some underlying disorder that may predispose them to sudden cardiac death?” Hill said. A fit heart tends to grow somewhat larger and beat more slowly, which can make it look similar on an ECG to a defective heart vulnerable to sudden cardiac death. This similarity could lead to unnecessary exclusion of healthy young people from sport participation.