title: Reduced risk of sudden death from chest wall blows (commotio cordis) with safety baseballs.
abstract: OBJECTIVE
  In an experimental model of sudden death from baseball chest wall impact (commotio cordis), we sought to determine if sudden death by baseball impact could be reduced with safety baseballs.
  
  
  BACKGROUND
  Sudden cardiac death can occur after chest wall impact with a baseball (commotio cordis). Whether softer-than-standard (safety) baseballs reduce the risk of sudden death is unresolved from the available human data. In a juvenile swine model, ventricular fibrillation (VF) has been shown to be induced reproducibly by precordial impact with a 30-mph baseball 10 to 30 ms before the T-wave peak, and this likelihood was reduced with the softest safety baseballs (T-balls). To further test whether safety baseballs would reduce the risk of sudden death at velocities more relevant to youth sports competition, we used our swine model of commotio cordis to test baseballs propelled at the 40-mph velocity commonly attained in that sport.
  
  
  METHODS
  Forty animals received up to 3 chest wall impacts at 40 mph during the vulnerable period of repolarization for VF with 1 of 3 different safety baseballs of varying hardness, and also by a standard baseball.
  
  
  RESULTS
  Safety baseballs propelled at 40 mph significantly reduced the risk for VF. The softest safety baseballs triggered VF in only 11% of impacts, compared with 19% and 22% with safety baseballs of intermediate hardness, and 69% with standard baseballs.
  
  
  CONCLUSIONS
  In this experimental model of low-energy chest wall impact, safety baseballs reduced (but did not abolish) the risk of sudden cardiac death. More universal use of these safety baseballs may decrease the risk of sudden death on the playing field for young athletes.
authors: Center for the Cardiovascular Evaluation of Athletes, the Cardiac Arrhythmia Center, New England Medical Center, Tufts University School of Medicine, Boston, Massachusetts 02111, USA. mlink@lifespan.org
authors: Mark S
authors: MS
authors: Link
authors: Barry J
authors: BJ
authors: Maron
authors: Paul J
authors: PJ
authors: Wang
authors: Natesa G
authors: NG
authors: Pandian
authors: Brian A
authors: BA
authors: VanderBrink
authors: N A Mark
authors: NA
authors: Estes
mesh_terms: D000818:Animals; D001265:Athletic Injuries / Q000401:mortality / Q000517:prevention & control; D001484:Baseball / Q000293:injuries* / Q000592:standards; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D004195:Disease Models, Animal; D006244:Hardness; D006335:Heart Injuries / Q000401:mortality / Q000517:prevention & control*; D006801:Humans; D011897:Random Allocation; D012307:Risk Factors; D019876:Sports Equipment / Q000592:standards*; D013552:Swine; D013898:Thoracic Injuries / Q000401:mortality / Q000517:prevention & control*; D014693:Ventricular Fibrillation / Q000209:etiology