Since news broke of the passing of Gaines Adams, the Bucs fourth overall pick in the 2007 draft, a lot of people are wondering why and/or how Adams’ enlarged heart was not tested for or detected by medical officials.

That may seem easier said than done, per a story from David Epstein of Sports Illustrated who writes that it’s not unusual for an enlarged heart to be misdiagnosed by medical officals.

When an athlete’s heart enlarges from training, it is the chambers that tend to enlarge more, and the muscle walls only slightly. In a diseased heart, such as an hypertrophic cardiomyopathy (HCM) heart, the chambers do not enlarge, while the walls thicken. The troubling gray area, according to Dr. Marty Maron, a cardiologist at Tufts Medical Center in Boston, is when there is mild enlargement of both the walls and the chambers in an athlete’s heart, leaving the possibility that the athlete has a heart enlarged from training, but might also have some underlying disease. “In that grey zone,” Maron says, “there can be some confusion in patients who are highly trained.” Differentiating the athlete’s heart from the diseased heart, Maron says, requires repeated imaging of the heart, with an echocardiogram or an MRI, for example, under the care of a doctor experienced with diagnosing HCM, and in some cases an athlete should be “deconditioned,” or told to stop training for several months. If the heart shrinks back to normal size, then the enlargement was due to training, and not to disease.

Dr. Paul D. Thompson, a cardiologist in Hartford, Conn., and an elite marathoner in the 1970s, says that he sees a lot of athletes, and it can be very difficult at times to differentiate “athlete’s heart” from a diseased heart. Thompson only knows about Adams’s case what he has read in the news, but he says that Adams’s underwhelming performance on the field piqued his interest, even though most people with HCM have no obvious symptoms. “When people aren’t performing well,” Thompson says, “you want to think of HCM.” The thickening of the heart wall in HCM impairs the heart muscle’s ability to relax to allow blood in, which can result in symptoms such as fatigue and shortness of breath. In fact, struggling athletes with HCM are often in danger of getting a misdiagnosis of asthma.

Thompson recounted the story of a boy named Francis who was taken in by Thompson’s father in the 1950s. Francis’s father and his aunt and uncle on his father’s side had all died of heart failure, and Thompson remembers that Francis always had trouble keeping up with other kids when they would play. More than two decades ago, Francis actually came to see Thompson, and Thompson gave him a diagnosis of HCM and advised that he get an implantable cardioverter-defibrillator (ICD), a device about the size of a matchbox that can be surgically implanted in the chest and shocks the heart back into a normal rhythm if it goes haywire. Francis did not get an ICD, and he died from cardiac arrest 10 years ago.

Joe hopes with the sad awareness of athletes dying of an enlarged heart, and the billions of dollars invested by professional sports teams in all leagues, that more precise if not thorough cardiac tests are performed.