ORLANDO, Nov. 12 -- Young athletes who drop dead without warning of unsuspected heart defects are widely publicized. But another type of sudden death on the playing field also kills many young sports participants each year -- and its victims have perfectly normal hearts.
At the American Heart Association's 70th Scientific Sessions, researchers report today on the first large study of "comotio cordis," a syndrome in which the heart stops beating after a direct blow to the chest from a baseball, hockey puck or other "high velocity objects."
Barry J. Maron, M.D., director of cardiovascular research at the Minneapolis Heart Institute Foundation and lead researcher in the study, says by focusing attention on comotio cordis, he and his colleagues hope to make coaches, athletes and bystanders more aware that it can occur and that quick recognition and response are essential to survival.
"Just realizing that this is a real problem is important," Maron says. "In many cases onlookers simply assume that it is not a serious situation and treatment is delayed until its too late. We need to educate people involved in sports about this risk.
"It appears that the blunt chest impact disrupts the rhythm of the heart," adds Maron. "It can be triggered by a blow from a baseball, softball or hockey puck and also by a collision with another player or an inanimate object such as a goal post."
In their study, researchers examined 55 cases of sudden cardiac arrest among young sports participants, 90 percent of whom were 16 years of age or younger. Twenty-five were playing in organized athletic events such as baseball, softball and ice hockey at the time, and 30 others were engaged in informal sports activities at home or school or on the playground. None of the youth showed evidence of any heart defect or disease.
"The blows they received caused no identifiable structural injury to the ribs, sternum or the heart itself and were, in effect, a relatively common occurrence in the games they were playing," says Maron.
"Fewer than one in 10 young athletes survived the incident, although all had normal, healthy hearts," Maron says. "But with faster recognition and prompt action, a large percentage of commotio cordis cases are potentially reversible with cardiopulmonary resuscitation (CPR)."
Response time is a critical factor in resuscitating victims of commotio cordis, Maron emphasizes. Of the five survivors in the study, four received CPR within one minute or less.
At present, better education and faster reaction are undoubtedly the best ways to reduce fatalities, but the issue of how to prevent potentially deadly chest blows from occurring in the first place also needs to be addressed, Maron adds.
"Making baseballs and softballs softer is one possibility," he says. "So is having batters in youth baseball wear chest protectors, but this may not be realistic. Altering equipment and the way games are played isn't a simple matter. For now, one of the best ways to save lives is through increased public awareness."
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