Protecting our children from the consequences of chest blows on the playing field: a time for science over marketing

Identifying Vulnerable Impact Locations to Reduce the Occurrence of Deadly Commotio Cordis Events in Children's Baseball: A Computational Approach

Commotio cordis is the second leading cause of sudden cardiac death in young athletes. Currently available chest protectors on the market are ineffective in preventing cases of commotio cordis in young athletes who play baseball. This study focused on using contour maps to identify specific baseball impact locations to the chest that may result in instances of commotio cordis to children during baseball games. By identifying these vulnerable locations, we may design and develop chest protectors that can provide maximum protection to prevent commotio cordis in young athletes. Simulation cases were run using the validated CHARM-10 chest model, a detailed finite element model representing an average 10-year-old child's chest. A baseball model was developed in company with the chest model, and then used to impact the chest at different locations. A 7 × 8 impact location matrix was designed with 56 unique baseball impact simulations. Left ventricle strain and pressure, reaction force between the baseball and chest, and rib deformations were analyzed. Left ventricle strain was highest from baseball impacts directly over the left ventricle (0.34) as well as impacts slightly lateral and superior to the cardiac silhouette (0.34). Left ventricle pressure was highest with impacts directly over the left ventricle (82.94 kPa). We have identified the most dangerous impact locations resulting in high left ventricle strain and pressure. This novel study provided evidence of where to emphasize protective materials for establishing effective chest protectors that will minimize instances of commotio cordis in young athletes.

Developing commotio cordis injury metrics for baseball safety: unravelling the connection between chest force and rib deformation to left ventricle strain and pressure

Commotio cordis is a sudden death mechanism that occurs when the heart is impacted during the repolarization phase of the cardiac cycle. This study aimed to investigate commotio cordis injury metrics by correlating chest force and rib deformation to left ventricle strain and pressure. We simulated 128 chest impacts using a simulation matrix which included two initial velocities, 16 impact locations spread across the transverse and sagittal plane, and four baseball stiffness levels. Results showed that an initial velocity of 17.88 m/s and an impact location over the left ventricle was the most damaging setting across all possible settings, causing the most considerable left ventricle strain and pressure increases. The impact force metric did not correlate with left ventricle strain and pressure, while rib deformations located over the left ventricle were strongly correlated to left ventricle strain and pressure. These results lead us to the recommendation of exploring new injury metrics such as the rib deformations we have highlighted for future commotio cordis safety regulations.

Cardiac injuries caused by trauma: Review and case reports

Assessment of suspected cardiac injuries in a trauma setting is a challenging and time-critical matter, with clinical and imaging findings having complementary roles in the formation of an accurate diagnosis. In this article, we review the supporting literature for the pathophysiology, classification and evaluation of cardiac injuries caused by trauma. We also describe 4 cardiac trauma patients seen at a tertiary referral hospital.

Commotio Cordis Caused by Violence in China: Epidemiological Characteristics Detected at the Tongji Forensic Medical Center

Commotio cordis (CC) is a recognized rare cause of sudden death in which an apparently minor blow to the chest causes ventricular fibrillation and cardiac arrest. CC diagnosis is still a challenge for forensic pathologists. A retrospective study of 9794 autopsy cases was conducted at the Department of Forensic Medicine, Tongji Medical College (DFM-TMC, China) from 1955 to 2014. A total of 39 cases (0.4%) were determined to be caused by CC. A male preponderance (male to female of 37:2) was found in the victims, whose age ranged from 13 to 47 years, including more than 85% individuals in their 10s and 20s. Most victims (27 cases, 69.2%) came from village. The highest rate of victims was found for middle school and college students (15 cases, 38.5%), followed by prisoners (11 cases, 28.2%), farmers (9 cases, 23.1%), workers (3 cases, 7.7%), and office staff (1 case, 2.6%). Chest blows were produced by fists (28 cases, 71.8%), feet (6 cases, 15.4%), knee (2 case, 5.1%), head (1 case, 2.6%), or objects (2 cases, 5.1%). Witness statements indicated that most victims collapsed after being impacted in the precordium. The autopsy findings were unremarkable except bruises, contusions, or subcutaneous hemorrhage in the anterior chest (13 cases), bleeding of intercostal muscles (5 cases), and disperse focal petechiae of the epicardium (11 cases). All CC cases in this study were caused by violent attacks and related to criminal processes. Correct diagnosis of CC due to violence has important implications in the judicial system.

Biomechanical considerations for assessing interactions of children and small occupants with inflatable seat belts

NHTSA estimates that more than half of the lives saved (168,524) in car crashes between 1960 and 2002 were due to the use of seat belts. Nevertheless, while seat belts are vital to occupant crash protection, safety researchers continue efforts to further enhance the capability of seat belts in reducing injury and fatality risk in automotive crashes. Examples of seat belt design concepts that have been investigated by researchers include inflatable, 4-point, and reverse geometry seat belts. In 2011, Ford Motor Company introduced the first rear seat inflatable seat belts into production vehicles. A series of tests with child and small female-sized Anthropomorphic Test Devices (ATD) and small, elderly female Post Mortem Human Subjects (PMHS) was performed to evaluate interactions of prototype inflatable seat belts with the chest, upper torso, head and neck of children and small occupants, from infants to young adolescents. Tests simulating a 6-year-old child asleep in a booster seat, with its head lying directly on its shoulder on top of the inflatable seat belt, were considered by engineering judgment, to represent a worst case scenario for interaction of an inflating seat belt with the head and neck of a child and/or small occupant. All evaluations resulted in ATD responses below Injury Assessment Reference Values reported by Mertz et al. (2003). In addition, the tests of the PMHS subjects resulted in no injuries from interaction of the inflating seat belt with the heads, necks, and chests of the subjects. Given the results from the ATD and PMHS tests, it was concluded that the injury risk to children and small occupants from deployment of inflatable seat belt systems is low.

Baseball and softball

Baseball and softball are among the most popular and safest sports in which children and adolescents participate. Nevertheless, traumatic and overuse injuries occur regularly, including occasional catastrophic injury and even death. Safety of the athlete is a constant focus of attention among those responsible for modifying rules. Understanding the stresses placed on the arm, especially while pitching, led to the institution of rules controlling the quantity of pitches thrown in youth baseball and established rest periods between pitching assignments. Similarly, field maintenance and awareness of environmental conditions as well as equipment maintenance and creative prevention strategies are critically important in minimizing the risk of injury. This statement serves as a basis for encouraging safe participation in baseball and softball. This statement has been endorsed by the Canadian Paediatric Society.

Commotio cordis and the epidemiology of sudden death in competitive lacrosse

OBJECTIVE

Athletic field risks associated with blunt, nonpenetrating chest blows (commotio cordis) are receiving increasing attention, but the epidemiology of these events is incomplete.

METHODS

We assessed our Sudden Death in Young Athletes Registry, 1980-2008, to formulate a clinical profile of those sudden deaths attributed to commotio cordis (and other causes) occurring in competitive lacrosse, the most rapidly growing youth sport in the United States.

RESULTS

Twenty-three sudden deaths or cardiac arrests were identified in high school and college lacrosse participants. Ages were 18 +/- 2 years; each athlete was male. Ten died after blunt precordial blows, including 4 goalies wearing commercially available chest protectors. Twelve others collapsed because of presumed or documented cardiovascular disease, including hypertrophic cardiomyopathy, long QT syndrome, mitral valve prolapse, or ruptured cerebral aneurysm. The mortality rate associated with lacrosse was 1.46 deaths per 100,000 person-years and was similar to that of other sports including baseball, basketball, football, and hockey. However, deaths attributed to commotio cordis were more frequent in lacrosse (0.63 deaths per 100,000 person-years) than in other sports (P < .02), with the exception of hockey.

CONCLUSIONS

Sudden deaths in competitive lacrosse participants are rare and no more common than in most other sports. These catastrophic events were caused disproportionately by commotio cordis and included athletes wearing chest barriers, thereby underscoring the importance of developing effective chest protection to create a safer athletic environment for our youth.

Sudden deaths in young competitive athletes: analysis of 1866 deaths in the United States, 1980-2006

BACKGROUND

Sudden deaths in young competitive athletes are highly visible events with substantial impact on the physician and lay communities. However, the magnitude of this public health issue has become a source of controversy.

METHODS AND RESULTS

To estimate the absolute number of sudden deaths in US competitive athletes, we have assembled a large registry over a 27-year period using systematic identification and tracking strategies. A total of 1866 athletes who died suddenly (or survived cardiac arrest), 19+/-6 years of age, were identified throughout the United States from 1980 to 2006 in 38 diverse sports. Reports were less common during 1980 to 1993 (576 [31%]) than during 1994 to 2006 (1290 [69%], P<0.001) and increased at a rate of 6% per year. Sudden deaths were predominantly due to cardiovascular disease (1049 [56%]), but causes also included blunt trauma that caused structural damage (416 [22%]), commotio cordis (65 [3%]), and heat stroke (46 [2%]). Among the 1049 cardiovascular deaths, the highest number of events in a single year was 76 (2005 and 2006), with an average of 66 deaths per year (range 50 to 76) over the last 6 years; 29% occurred in blacks, 54% in high school students, and 82% with physical exertion during competition/training, whereas only 11% occurred in females (although this increased with time; P=0.023). The most common cardiovascular causes were hypertrophic cardiomyopathy (36%) and congenital coronary artery anomalies (17%).

CONCLUSIONS

In this national registry, the absolute number of cardiovascular sudden deaths in young US athletes was somewhat higher than previous estimates but relatively low nevertheless, with a rate of <100 per year. These data are relevant to the current debate surrounding preparticipation screening programs with ECGs and also suggest the need for systematic and mandatory reporting of athlete sudden deaths to a national registry.