How enlarged hearts in athletes like Bears DE can go undetected
The sudden, unexpected death of a young athlete -- like that of
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.
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
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
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.