How enlarged hearts in athletes like Bears DE can go undetected

Lacking a sensible explanation, message boards filled up with anonymous commenters suggesting Adams must have abused drugs. Some SI.com writers received e-mails from readers asking how an enlarged heart could possibly have been missed in Adams's physical exams. Others wrote in to say that a doctor had once told them they had an enlarged heart, and they now wonder if they are in grave danger. The short answer is that the finding of an "enlarged heart" is quite normal for athletes, whose hearts, like any muscle, grow from exercise. There is a difference in a heart enlarged by exercise and one enlarged by disease, and the two can sometimes be difficult to tell apart. But before I learned any of that, I had the exact same questions back in 2000 when a close friend dropped dead.

Kevin Richards had been my training partner on the track team at Evanston Township High. As a sophomore, he was part of a state championship 4x 800-meter relay that ran one of the top 10 times in the nation. The son of Jamaican immigrants, Kevin was primed to be the first member of his family to attend college. Then came a dinky indoor track meet on Feb. 12, 2000. A few steps after Kevin took second in the mile, he put his hands on his hips, and then collapsed to the rubber floor in cardiac arrest. He died right there on our home track. Kevin's sudden death was the first obvious symptom of his dangerously enlarged heart. An autopsy showed that Kevin had a huge heart, and that he had hypertrophic cardiomyopathy (HCM), a genetic disease and the most common cause of sudden death in athletes. (HCM is suspected in the deaths of Adams and Lewis, but an official cause of death is still unknown). At least one athlete in America, from high school to pros, will die from HCM about every other week while playing or practicing. The disease causes an abnormal thickening of the heart, and affects 1 in every 500 adults. In an HCM heart, the heart cells are also stacked in an erratic pattern, as opposed to in the orderly manner of bricks in a wall, which can cause the electric signals in the heart to go haywire and lead to a fatal rhythm in which the heart essentially trembles instead of flexing and relaxing methodically. Most people who have HCM are not at risk of suddenly dropping dead, but the disease is nonetheless the most common cause of sudden, natural death in young people. How could Kevin's enlarged heart have been missed during his pre-participation physical? I wondered. It's the same question we now ask about Adams.

First, it is not surprising that Adams had an enlarged heart, nor would it be a surprise if any other athlete has an enlarged heart, but that does not mean it's dangerous. The heart is made up, essentially, of chambers, tubes, and walls. Blood comes into the chambers where the muscular walls can squeeze shut to send it hurtling through the tubes to the lungs. There, the blood picks up oxygen, goes back to the heart and it is once again propelled by the contraction of the walls out to the muscles where it will drop off the oxygen. The harder an athlete is working, the more oxygen, and thus blood, needs to get to those muscles. So as one trains, the heart muscle gets bigger, both the chambers and the walls, so that more blood can be moved with each pump. Many people who exercise regularly notice that their resting pulse rate drops, and that is because the strengthened heart does not need to pump as often to move blood. So it's no surprise that Adams would have an enlarged heart. But the devil is in the details.

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 HCM heart, the chambers do not enlarge, while the walls thicken. The troubling gray area, according to Dr. Martin 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.

With athletes ICDs can be a particularly thorny subject. According to Dr. Mark Estes, an electrophysiologist and director of the New England Cardiac Arrhythmia Center, ICDs are not made to withstand vigorous activity, so athletes who have them are generally advised not to participate in intense sports. Some athletes, though, opt to ignore that advice. Last year, Belgian soccer pro Anthony Van Loo collapsed during a game and was shocked back to life by his ICD. Rachel Lampert, an associate professor of medicine at Yale University runs a registry that tracks athletes -- 241 of them so far -- who participate with ICDs, in the hope of learning more about how ICDs function during sports.

The overwhelming question that deaths of young athletes like Adams and Lewis leave us with, of course, is how not to let it happen again. Often there is the call for universal screening for athletes using electrocardiograms, or EKGs, which record the electrical signals of the heart, and can be done for $50 in only a few minutes. In Italy, all athletes get EKGs, and sudden death in athletes is nearly nonexistent. If Italy can do it, why can't we? For one, it takes a trained eye to analyze the EKG, and the U.S. has 37 percent fewer doctors per capita than Italy, a country that threw open the doors to its medical schools after World War II. The U.S. has as many high school athletes (about 7.3 million) as Italy has high school-aged people, and they are far more genetically and geographically diverse in the U.S. The result of universal EKGs would probably be to catch some cases of HCM, but more often to worry a lot of athletes and parents with false positives or inconclusive readings.

What can be done cheaply, however, is for families to know their own history. If there are relatives who have died of cardiac causes before age 50, suspicion should be high that a disease like HCM may run in the family. Additionally, some physicians might become suspicious based on the characteristics of a heart murmur they hear when examining an athlete with a stethoscope, and order follow up exams to test for HCM. Unfortunately, in recent years an increasing number of states have decided to allow non-physicians, such as chiropractors who are not cardiovascular experts, to conduct pre-participation physicals.

Ultimately, it is unlikely that sudden death in athletes can be entirely prevented in this country. But certainly increasing awareness of diseases like HCM, and an understanding of what it might mean to have an "enlarged heart" are key steps to recognizing disease and protecting athletes. We can only hope that the deaths of Adams and Lewis have at least gone a little way toward those ends.