Blunt impact to the chest leading to sudden death from cardiac arrest during sports activities

Commotio cordis: Another cardiac arrest "sine materia". The 1707 early report and interpretation by G.M. Lancisi

Sudden death by commotio cordis is rare. It is the consequence of a blunt trauma of the chest overlying the heart. The mechanism is a cardiac arrest by ventricular fibrillation in the absence of grossly or microscopically apparent myocardial injury. It has been reproduced in animals. The first historical case was reported by Giovanni Maria Lancisi in his book "De Subitaneis Mortibus'' published in 1707. Sudden death occurred in a man receiving a powerful blow under the xiphoid cartilage. Lancisi advanced the hypothesis of acute heart failure by a diastolic stand still ("death in diastole'').

Development of the NOCSAE Standard to Reduce the Risk of Commotio Cordis

BACKGROUND

Commotio cordis, sudden cardiac death (SCD) caused by relatively innocent impact to the chest, is one of the leading causes of SCD in sports. Commercial chest protectors have not been demonstrated to mitigate the risk of these SCDs.

METHODS

To develop a standard to assess chest protectors, 4 phases occurred. A physiological commotio cordis model was utilized to assess variables that predicted for SCD. Next, a surrogate model was developed based on data from the physiological model, and the attenuation in risk was assessed. In the third phase, this model was calibrated and validated. Finally, National Operating Committee on Standards for Athletic Equipment adopted the standard and had an open review process with revision of the standard over 3 years.

RESULTS

Of all variables, impact force was the most robust at predicting SCD. Chest wall protectors which could reduce the force of impact to under thresholds were predicted to reduce the risk of SCD. The correlation between the experimental model and the mechanical surrogate ranged from 0.783 with a lacrosse ball at 30 mph to 0.898 with a baseball at 50 mph. The standard was licensed to National Operating Committee on Standards for Athletic Equipment which initially adopted the standard in January 2018, and finalized in July 2021.

CONCLUSIONS

An effective mechanical surrogate based on physiological data from a well-established model of commotio cordis predicts the reduction in SCD with chest protectors. A greater reduction in force provides a great degree of protection from commotio cordis. This new National Operating Committee on Standards for Athletic Equipment standard for chest protectors should result in a significant reduction in the risk of commotio cordis on the playing field.

Catastrophic Sports Injuries: Causation and Prevention

➤ Catastrophic injuries in U.S. high school and college athletes are rare but devastating injuries.➤ Catastrophic sports injuries are classified as either traumatic, caused by direct contact during sports participation, or nontraumatic, associated with exertion while participating in a sport.➤ Football is associated with the greatest number of traumatic and nontraumatic catastrophic injuries for male athletes, whereas cheerleading has the highest number of traumatic catastrophic injuries and basketball has the highest number of nontraumatic catastrophic injuries for female athletes.➤ The incidence of traumatic catastrophic injuries for all sports has declined over the past 40 years, due to effective rule changes, especially in football, pole-vaulting, cheerleading, ice hockey, and rugby. Further research is necessary to reduce the incidence of structural brain injury in contact sports such as football.➤ The incidence of nontraumatic catastrophic injuries has increased over the last 40 years and requires additional research and preventive measures. Avoiding overexertion during training, confirming sickle cell trait status in high school athletes during the preparticipation physical examination, and developing cost-effective screening tools for cardiac abnormalities are critical next steps.

Commotio Cordis: A Comprehensive Review

Commotio cordis is a rare, however, potentially fatal, cardiovascular phenomenon arising from direct chest wall trauma, causing sudden cardiac arrest and potentially death. It is primarily seen in young athletes who participate in contact and organized sports. Though debated, the cause of commotio cordis is believed to involve specific timing of chest impact during ventricular electrical activity leading to severe arrhythmic events. Due to sudden onset, the first step in management is immediate and effective basic life support with automated external defibrillation, followed by advanced cardiac life support. Future considerations should include secondary prevention measures such as protective padding in contact sports. It is paramount that clinicians are vigilant in recognizing potential cases of commotio cordis in the field and provide immediate care. This review consolidates the current understanding of commotio cordis, emphasizing the importance of awareness and early intervention. Future research is warranted, including retrospective and observational studies to identify high-risk patterns or trends associated with the condition.

Advancing Commotio cordis Safety Standards Using the Total Human Models for Safety (THUMS)

Commotio cordis is one of the leading causes of sudden cardiac death in youth baseball. Currently, there are chest protector regulations regarding the prevention of Commotio cordis in baseball and lacrosse; however, they are not fully optimized. For the advancement of Commotio cordis safety, it is vital to include various age groups and a variety of impact angles in the testing process. This study employed finite element models and simulated Commotio cordis-inducing baseball collisions for different velocities, impact angles, and age groups. Commotio cordis risk response was characterized in terms of left ventricular strain and pressure, chest band and rib deformation, and force from impact. Normalized rib and chest band deformation when correlated with left ventricular strain resulted in R2 = 0.72, and R2 = 0.76, while left ventricular pressure resulted in R2 = 0.77, R2 = 0.68 across all velocities and impact angles in the child models. By contrast, the resultant reaction force risk metric as used by the National Operating Committee on Standards for Athletic Equipment (NOCSAE) demonstrated a correlation of R2 = 0.20 in the child models to ventricular strain, while illustrating a correlation to pressure of R2 = 0.74. When exploring future revisions to Commotio cordis safety requirements, the inclusion of deformation-related risk metrics at the level of the left ventricle should be considered.

Commotio Cordis Returns…When We Least Expected It: Cardiac Arrest in A Professional Football Player

For the first time in 52 years, an American professional football player (Damar Hamlin) collapsed in cardiac arrest during a game, viewed in real-time on national television. The cause of this profound event was commotio cordis, that is, blunt non-penetrating chest blow-initiated ventricular fibrillation triggered by physical contact not considered unusual for football. The athlete survived because of timely cardiopulmonary resuscitation and defibrillation provided by first responders organized by the National Football League. Commotio cordis, albeit rare, was most prominently identified initially in competitive and also recreational sports participants. More recently it became apparent that similar events could occur in almost any circumstance involving a chest blow, such as during everyday activities around the home and with innocent play. The determinant of a commotio cordis event is a blow over the heart in a narrow vulnerable electrical window during dispersion of repolarization. Survival from these events has increased substantially to >60% due to enhanced recognition and prompt resuscitation/defibrillation. In conclusion, in this commentary, we take a timely opportunity to describe in detail the relevant demographics, mechanism/pathophysiology, and clinical course of commotio cordis.

Commotio Cordis in 2023

Since the nationally televised cardiac arrest of American National Football League player Damar Hamlin in January 2023, commotio cordis has come to the forefront of public attention. Commotio cordis is defined as sudden cardiac arrest due to direct trauma to the precordium resulting in ventricular fibrillation or ventricular tachycardia. While the precise incidence of commotio cordis is not known due to a lack of standardized, mandated reporting, it is the third most common cause of sudden cardiac death in young athletes, with more than 75% of cases occurring during organized and recreational sporting events. Given that survival is closely tied to how quickly victims receive cardiopulmonary resuscitation and defibrillation, it is crucial to raise awareness of commotio cordis so that athletic trainers, coaches, team physicians, and emergency medical personnel can rapidly diagnose and treat this often-fatal condition. Broader distribution of automated external defibrillators in sporting facilities as well as increased presence of medical personnel during sporting events would also likely lead to higher survival rates.

Commotio Cordis in Non-Sport-Related Events: A Systematic Review

BACKGROUND

Commotio cordis is an increasingly recognized cause of sudden cardiac death. Although commonly linked with athletes, many events occur in non-sport-related settings.

OBJECTIVES

The goal of this study was to characterize and compare non-sport-related vs sport-related commotio cordis.

METHODS

PubMed and Embase were searched for all cases of commotio cordis from inception to January 5, 2022.

RESULTS

Of 334 commotio cordis cases identified, 121 (36%) occurred in non-sport-related contexts, which included assault (76%), motor vehicle accidents (7%), and daily activities (16%). Projectiles were implicated significantly less in non-sport-related events (5% vs 94%, respectively; P < 0.001). Nonprojectile etiologies in non-sport-related events mostly consisted of impacts with body parts (79%). Both categories affected similar younger aged demographic (P = 0.10). The proportion of female victims was significantly higher in non-sport-related events (13% vs 2%, respectively; P = 0.025). Mortality was significantly higher in non-sport-related events (88% vs 66%, respectively; P < 0.001). In non-sport-related events, rates of cardiopulmonary resuscitation (27% vs 97%, respectively; P < 0.001) and defibrillation (17% vs 81%, respectively; P < 0.001) were both lower and resuscitation was more commonly delayed beyond 3 min (80% vs 5%, respectively; P < 0.001).

CONCLUSIONS

Commotio cordis occurs across a spectrum of non-sport-related settings including assault, motor vehicle accidents, and daily activities. Both categories affected a younger and male-predominant demographic. Mortality is higher in non-sport-related commotio cordis, likely owing to lower rates of cardiopulmonary resuscitation, defibrillation, automated external defibrillator availability, and extended time to resuscitation. Increased awareness of non-sport-related commotio cordis is essential to develop a means of prevention and mortality reduction, with earlier recognition and prompt resuscitation measures.

Sudden Cardiac Death: An Update on Commotio Cordis

Sudden cardiac death (SCD) is one of the leading causes of cardiovascular mortality, and it is caused by a diverse array of conditions. Among these is commotio cordis, a relatively infrequent but still significant cause, often seen in young athletes involved in competitive or recreational sports. It is known to be caused by blunt trauma to the chest wall resulting in life-threatening arrhythmia (typically ventricular fibrillation). The current understanding pertains to blunt trauma to the precordium, with an outcome depending on factors such as the type of stimulus, the force of impact, the qualities of the projectile (shape, size, and density), the site of impact, and the timing of impact in relation to the cardiac cycle. In the management of commotio cordis, a history of preceding blunt chest trauma is usually encountered. Imaging is mostly unremarkable except for ECG, which may show malignant ventricular arrhythmias. Treatment is focused on emergent resuscitation with the advanced cardiac life support protocol algorithm, with extensive workup following the return of spontaneous circulation. In the absence of underlying cardiovascular pathologies, implantable cardiac defibrillator insertion is not beneficial, and patients can even resume physical activity if the workup is unremarkable. Proper follow-up is also key in the management and monitoring of re-entrant ventricular arrhythmias, which are amenable to ablative therapy. Prevention of this condition involves protecting the chest wall against blunt trauma, especially with the use of safety balls and chest protectors in certain high-risk sporting activities.  This study aims to elucidate the current epidemiology and clinical management of SCD with a particular focus on a rarely explored etiology, commotio cordis.

Adhesive cryogel particles for bridging confined and irregular tissue defects

BACKGROUND

Reconstruction of damaged tissues requires both surface hemostasis and tissue bridging. Tissues with damage resulting from physical trauma or surgical treatments may have arbitrary surface topographies, making tissue bridging challenging.

METHODS

This study proposes a tissue adhesive in the form of adhesive cryogel particles (ACPs) made from chitosan, acrylic acid, 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The adhesion performance was examined by the 180-degree peel test to a collection of tissues including porcine heart, intestine, liver, muscle, and stomach. Cytotoxicity of ACPs was evaluated by cell proliferation of human normal liver cells (LO2) and human intestinal epithelial cells (Caco-2). The degree of inflammation and biodegradability were examined in dorsal subcutaneous rat models. The ability of ACPs to bridge irregular tissue defects was assessed using porcine heart, liver, and kidney as the ex vivo models. Furthermore, a model of repairing liver rupture in rats and an intestinal anastomosis in rabbits were established to verify the effectiveness, biocompatibility, and applicability in clinical surgery.

RESULTS

ACPs are applicable to confined and irregular tissue defects, such as deep herringbone grooves in the parenchyma organs and annular sections in the cavernous organs. ACPs formed tough adhesion between tissues [(670.9 ± 50.1) J/m² for the heart, (607.6 ± 30.0) J/m² for the intestine, (473.7 ± 37.0) J/m² for the liver, (186.1 ± 13.3) J/m² for muscle, and (579.3 ± 32.3) J/m² for the stomach]. ACPs showed considerable cytocompatibility in vitro study, with a high level of cell viability for 3 d [(98.8 ± 1.2) % for LO2 and (98.3 ± 1.6) % for Caco-2]. It has comparable inflammation repair in a ruptured rat liver (P = 0.58 compared with suture closure), the same with intestinal anastomosis in rabbits (P = 0.40 compared with suture anastomosis). Additionally, ACPs-based intestinal anastomosis (less than 30 s) was remarkably faster than the conventional suturing process (more than 10 min). When ACPs degrade after surgery, the tissues heal across the adhesion interface.

CONCLUSIONS

ACPs are promising as the adhesive for clinical operations and battlefield rescue, with the capability to bridge irregular tissue defects rapidly.

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.

The Effect of Athletic Chest Protectors on the Performance of Manual and Mechanical CPR: A Simulation Study

OBJECTIVES

Sudden cardiac arrest is a leading cause of death in athletes. Although athletes wear various athletic chest protectors (ACPs) to prevent commotio cordis (CC), cardiac arrest cases still occur. Although it is established that cardiopulmonary resuscitation (CPR) quality affects outcome, little research has evaluated the effect of ACPs on CPR compressions quality. This study aimed to observe whether: (1) ACPs impact depth, rate, and hand positioning of both bystander and LUCAS CPR. (2) LUCAS devices affect CPR performance compared with traditional compressions.

METHODS

An observational, prospective, convenient sample of 26 emergency medicine residents performed CPR on a high-fidelity Laerdal mannequin, which recorded real-time performance data. Baseline CPR for 1- and 2-minute cycles, CPR on a mannequin wearing the ACP, and ACP removal time was recorded. LUCAS CPR performance was measured at baseline and over the ACP.

RESULTS

Bystander CPR had a statistically significant difference in both hand placement and compression rate for baseline versus ACP compressions (85% vs 57%, P < 0.05; 138 vs 142, P < 0.05, respectively), but not in compression depth (51.08 vs 50.05 mm, P = 0.39). LUCAS CPR had no significant difference in CPR performance. Bystander versus LUCAS CPR had a significant difference in compression rate (138 vs 101, P < 0.01), but not in depth or hand placement.

CONCLUSIONS

Athletic chest protectors significantly impacted hand placement during bystander CPR, which may diminish CPR quality. Considering ACP removal required only 5.4 seconds, removing the ACP before standard CPR may improve quality.

Overview of Sport-Specific Injuries

Athletes are at risk for a variety of injuries not typically sustained in everyday life. The team physician must be capable of not only identifying and treating injuries as they occur, but he or she must be armed with the knowledge to minimize the risk of injuries before they occur. This review serves to provide an overview of the various sport-specific injuries typically encountered by team physicians. Injuries are grouped by body part and/or organ system, when possible. We do not aim to cover in detail the various treatments for these injuries; rather, we hope that this article provides a comprehensive overview of sport-specific injury, and demonstrate the well-roundedness in skills that must be possessed by team physicians.

Blunt Trauma to the Heart: A Review of Pathophysiology and Current Management

Blunt cardiac injury (BCI), defined as an injury to the heart from blunt force trauma, ranges from minor to life-threatening. The majority of BCIs are due to motor vehicle accidents; however, injuries caused by falls, blasts, and sports-related injuries also can be sources of BCI. A significant proportion of patients with BCI do not survive long enough to receive medical care, succumbing to their injuries at the scene of the accident. Additionally, patients with blunt trauma often have coexisting injuries (brain, spine, orthopedic) that can obscure the clinical picture; therefore, a high degree of suspicion often is required to diagnose BCI. Traditionally, hemodynamically stable injuries suspicious for BCI have been evaluated with electrocardiograms and chest radiographs, whereas hemodynamically unstable BCIs have received operative intervention. More recently, computed tomography and echocardiography increasingly have been utilized to identify injuries more rapidly in hemodynamically unstable patients. Transesophageal echocardiography can play an important role in the diagnosis and management of several BCIs that require operative repair. Close communication with the surgical team and access to blood products for potentially massive transfusion also play key roles in maintaining hemodynamic stability. With proper surgical and anesthetic care, survival in cases involving urgent cardiac repair can reach 66%-to-75%. This narrative review focuses on the types of cardiac injuries that are caused by blunt chest trauma, the modalities and techniques currently used to diagnose BCI, and the perioperative management of injuries that require surgical correction.

Don't Forget Commotio Cordis

Non-penetrating chest blows can occasionally trigger fatal ventricular tachyarrhythmias and sudden death (commotio cordis). Such events were initially reported in association with sporting activities and projectiles such as baseball/lacrosse balls. However, similar potentially fatal chest blows, seemingly incapable of causing death, can occur during a variety of other circumstances such as when delivered during a fight (by a fist) such as in the accompanying paper. Notably, commotio cordis events can be reversed by resuscitation and defibrillation.

Commotio cordis: A case report of a fatal blow

Commotio cordis secondary to a blunt blow to the chest wall can result in ventricular fibrillation and sudden death in children. While it is commonly reported in adolescents during sporting activities, it may result from non-accidental trauma especially in infants and younger children. We report a case of a 6-month-old baby boy who presented to the emergency department in cardiac arrest. The patient's hospital records, postmortem imaging, and the autopsy results were reviewed. External examination of the infant did not reveal any evidence of trauma. Postmortem imaging revealed multiple healing posterior rib fractures and a metaphyseal corner fracture, both considered fractures highly specific for physical abuse. The autopsy revealed a structurally normal heart with no microscopic abnormalities. The infant's father confessed to hitting the child on the chest after which the child became unresponsive. Given the constellation of postmortem imaging and autopsy findings in addition to the father's confession, the child's death was ruled as a homicide secondary to commotio cordis. Since there are no structural and microscopic abnormalities in the heart autopsy in cases of commotio cordis, timely on-scene investigation and a thorough investigation regarding the mechanism of injury are required to make this diagnosis. Early identification of non-accidental trauma is crucial and can prevent further abuse in other siblings.

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.

Sudden cardiac death risk in contact sports increased by myocarditis: a case series

Background

Myocarditis is a known cause of sudden cardiac death of the athlete. The impact of direct chest trauma in at-risk sports or activities in patients with a history of myocarditis has never been demonstrated or studied. We report herein two cases of life-threatening ventricular arrhythmia secondary to non-penetrating blunt chest trauma while playing contact sports.

Case summary

The first patient, a 26-year-old man described a brief loss of consciousness after having received blunt impact to the chest (typical intensity) while playing a rugby match. The loss of consciousness was total and proceeded by rapid and regular palpitations. He had a history of viral myocarditis 10 years prior with a fibrotic sequalae in the inferolateral wall on cardiac magnetic resonance imaging (left ventricular ejection fraction 71%). Right apical ventricular pacing induced a sustained monomorphic ventricular tachycardia reproducing the patient's symptoms. A subcutaneous implantable cardioverter-defibrillator was implanted. The second patient is a 22-year-old professional rugby player with no known notable history. During a match, a direct blow to the chest wall was followed by a cardiac arrest. A ventricular fibrillation was cardioverted to pulseless electrical activity. Patient died despite cardiopulmonary resuscitation. An autopsy identified a myocardial sequela of fibrosis with no acute inflammatory remodelling compatible with a previous myocarditis.

Discussion

Myocarditis may increase the risk of life-threatening ventricular arrhythmias caused by blunt impact to the chest, particularly in contact sports. Screening and prevention measures should be considered to reduce this risk.

Outcome analysis of traumatic out-of-hospital cardiac arrest patients according to the mechanism of injury: A nationwide observation study

The variation in the outcome of traumatic out-of-hospital cardiac arrest (TOHCA) patients according to the mechanism of injury has been relatively unexplored. Therefore, this study aimed to determine whether the mechanism of injury is associated with survival to hospital discharge and good neurological outcome at hospital discharge in TOHCA.The study population comprised cases of TOHCA drawn from the national Out-of-hospital cardiac arrest registry (2012-2016). Traumatic causes were categorized into 6 groups: traffic accident, fall, collision, stab injury, and gunshot injury. Data were retrospectively extracted from emergency medical service and Korean Centers for Disease Control and Prevention records. Multivariate logistic regression analysis was used to identify factors associated with survival to discharge and good neurological outcome.The final analysis included a total of 8546 eligible TOHCA patients (traffic accident 5300, fall 2419, collision 572, stab injury 247, and gunshot injury 8). The overall survival rate was 18.4% (traffic accident 18.0%, fall 16.4%, collision 32.0%, stab injury 14.2%, and gunshot injury 12.5%). Good neurological outcome was achieved in 0.8% of all patients (traffic accident 0.8%, fall 0.8%, collision 1.2%, stab injury 0.8%, and gunshot injury 0.0%). In the multivariate analysis, injury mechanisms showed no significant difference in neurological outcomes, and only collision had a significant odds ratio for survival to discharge (odds ratio: 2.440; 95% confidence interval: 1.795-3.317) compared to the traffic accident group.In this study, the mechanism of injury was not associated with neurological outcome in TOHCA patients. Collision might be the only mechanism of injury to result in better survival to discharge than traffic accident.

Cardiac Mechano-Electric Coupling: Acute Effects of Mechanical Stimulation on Heart Rate and Rhythm

The heart is vital for biological function in almost all chordates, including humans. It beats continually throughout our life, supplying the body with oxygen and nutrients while removing waste products. If it stops, so does life. The heartbeat involves precise coordination of the activity of billions of individual cells, as well as their swift and well-coordinated adaption to changes in physiological demand. Much of the vital control of cardiac function occurs at the level of individual cardiac muscle cells, including acute beat-by-beat feedback from the local mechanical environment to electrical activity (as opposed to longer term changes in gene expression and functional or structural remodeling). This process is known as mechano-electric coupling (MEC). In the current review, we present evidence for, and implications of, MEC in health and disease in human; summarize our understanding of MEC effects gained from whole animal, organ, tissue, and cell studies; identify potential molecular mediators of MEC responses; and demonstrate the power of computational modeling in developing a more comprehensive understanding of ‟what makes the heart tick.ˮ.

Prevention of Sudden Death Related to Sport: The Science of Basic Life Support-from Theory to Practice

The sudden cardiac arrest (CA) and death of athletes are dramatic and emotionally impacting events for health professionals, family, and society. Although the practice of sport participation improves general health, physical fitness, and quality of life, intense physical exercise can be a trigger for CA and sudden death occasionally in the presence of known or unknown cardiac disorders (mainly hypertrophic cardiomyopathy) and risk factors (environment, health style, family, and genetic). The present review found that sudden death associated with CA was not such a common event in competitive athletes, but it might be an underestimated event in recreational athletes. Thus, considering the exponential increase in sport participation, both in a recreational or competitive way, and the rate of sudden CA, knowledge of implementing prevention and treatment strategies is crucial. This includes preparation of health professionals and lay people in basic life support (BLS); screening and pre-participation assessment in sport programs and health education; and promotion for the recognition of CA and early completion of BLS and rapid access to automatic external defibrillator to improve the victim survival/prognosis. Thus, the purpose of this review is to provide for health professionals and lay people the most updated information, based on current guidelines, of how to proceed in an emergency situation associated with sudden CA of young adult athletes.

Diagnostic Criteria for Commotio Cordis Caused by Violent Attack: Review of the Literature

The diagnosis of lethal commotio cordis (CC) is really complex. The forensic pathologist's task is even more relevant when he/she has to explain a CC diagnosis caused by an assault in a trial. The purpose of this study was to analyze the literature on lethal CC as a result of violent attacks and identify relevant parameters that may help in the diagnosis. A review of the relevant articles was performed. Fifty-two cases of CC caused by violent attacks were identified. The collected data allowed to confirm the following literature's criteria for CC diagnosis in case of assaults: witnessed occurrence of a blunt, nonpenetrating blow to the chest preceding cardiovascular collapse; absence of structural damage to the sternum, ribs, or heart itself; and absence of any underlying cardiovascular abnormalities (such as other causes of sudden death). Regarding the assessment of the third criterion, the authors suggest that the pathologist should always specify the scientific autopsy guidelines that he/she used to differentiate CC from the other causes of sudden death. In addition, the authors highlight the importance of a multidisciplinary approach for a correct interpretation of clinical, autopsy, and laboratory findings.

Size as an Important Determinant of Chest Blow-induced Commotio Cordis

PURPOSE

Commotio cordis is sudden cardiac death caused by a relatively innocent blow to the left chest wall. Adolescents account for the majority of the cases; whether this is due to the higher frequency of adolescents playing ball sports or whether there is some maturational reduction of risk is not known.

METHODS

In a swine model of commotio cordis, the effect of body weight/size (directly related to age) to the susceptibility of chest impact-induced ventricular fibrillation (VF) is examined.

METHODS

Ball impacts were delivered at escalating velocities from 48.3 to 96.9 km·h (30-60 mph) to 128 swine ranging in weight from 5 to 54 kg.

RESULTS

VF occurred in 29% of impacts to the smallest animals compared with 34% in the 14- to 239-kg group, 27% in the 24- to 33.9-kg group, 30% in 34- to 43-kg group, and 15% in the 44- to 54-kg animals. The highest-weight group was associated with a significantly lower incidence of VF compared with other weights (P = 0.002). In a multivariate logistic regression analysis, controlling for repeated measures, four variables predicted VF: body weight (P = 0.0008), velocity (P < 0.0001), distance from the center of the heart, (P < 0.0001), and peak left ventricular pressure induced by the blow (P = 0.0007).

CONCLUSIONS

In this experimental model, animals weighing <44 kg seem to have a similar susceptibility to commotio cordis, whereas animals weighing ≥44 kg have a lower susceptibility. An increase in size of the individual, rather than reduced play of ball sports, is the likely reason for the decreased commotio cordis incidence in older individuals.

Thoracoabdominal Injuries

Trauma to the thorax and abdomen can occur during participation in sports. This chapter reviews some of the more common presentations of such injuries and how such injuries should be best managed. Thoracic injuries reviewed include internal injuries such as pneumothorax, pulmonary contusion, hemothorax, commotio cordis, and cardiac contusion. Chest wall injuries are also reviewed such as rib fractures, costochondritis, and slipping rib syndrome plus sternal and scapular fractures. Abdominal injuries reviewed are focused on internal organ trauma to the spleen and liver, kidney, pancreas, and bowel. There is attention to the effect of Epstein-Barr virus and infectious mononucleosis, seen very frequently in high school and collegiate athletes. Finally, groin pain and athletic pubalgia are described.

In addition to anatomy and clinical presentation, imaging modalities that characterize such trauma are reviewed for each diagnosis. Prevention of thoracoabdominal injuries and return-to-play decisions are described at the chapter conclusion.

Early recognition of sudden cardiac arrest in athletes during sports activity

INTRODUCTION

Sudden cardiac arrest (SCA) in athletes is an unexpected life-threatening event, which is often not recognised early and cardiopulmonary resuscitation (CPR) is not always initiated immediately. We describe key features to rapidly recognise non-traumatic SCA in athletes during sports activity.

METHODS

We reviewed videos and images of athletes suffering from non-traumatic SCA during sports activity. We searched Google images, Google videos and YouTube.com using the keywords 'sudden cardiac death athlete' and 'resuscitation athlete'. We analysed (1) the athlete's performance before syncope, (2) the athlete's performance at the start of syncope, (3) the position of the body, and (4) the athlete's facial expressions before CPR. We analysed our data by describing these four features to answer our research question.

RESULTS

We analysed the sequence of events in six well-known soccer players in whom a camera-witnessed non-traumatic SCA occurred during their athletic activity. All six athletes showed no changes before syncope. Four became unstable while standing and unexpectedly collapsed falling on their back. Two suddenly 'dropped dead' and fell face down. All six had their eyes wide open with a fixed gaze and fixed pupils.

CONCLUSIONS

Sudden unexpected loss of consciousness in an athlete in action and a fixed gaze eye position are key features of SCA. Immediate cardiac massage should follow. The described features to immediately recognise SCA in athletes during sports activity should be taught to everyone involved in athletic activity leading to earlier recognition of SCA followed by earlier CPR.

THORAX INJURY CRITERIA ASSESSMENT THROUGH NON-LETHAL IMPACT USING AN ENHANCED BIOMECHANICAL MODEL

Ballistic injury refers to the interaction of a projectile and the human body, resulting in penetration or blunt trauma. In order to consider both consequences, a hydrodynamic elastoplastic constitutive law was implemented in a numerical FE model of the human torso to simulate soft tissues behavior and to evaluate their injury risk. This law, derived from 20% ballistic gelatin, was proven to be very efficient and biofidelic for penetrating ballistic simulation in soft tissues at very high velocity. In this study, the ability of the hydrodynamic law to simulate blunt ballistic trauma is evaluated by the replication of Bir et al.’s (2004) experiments, which is a reference test of the literature for nonpenetrating ballistic impact. Lung injury criteria were also investigated through the Bir et al.’s experiments numerical replication. Human responses were evaluated in terms of mechanical parameters, which can be global (acceleration of the body, viscous criteria and impact force) or local (stress, pressure and displacement). Output results were found to be in experimental corridors developed by Bir et al., and the maximum pressure combined with the duration of the peak of pressure in the lungs seems to be a good predictor for lung injury.

Commotio cordis: A review

Commotio cordis is an increasingly reported fatal mechano-electric syndrome and is the second most common cause of sudden cardiac death in young athletes. It is most commonly associated with a sports-related injury, wherein, there is a high-velocity impact between a projectile and the precordium. By virtue of this impact, malignant arrhythmias consequently develop leading to the individual's immediate demise, accompanied by a relatively normal post-mortem analysis. The importance of an autopsy remains paramount to exclude other causes of sudden death. With increasing awareness and reporting, survival rates are beginning to improve; however, prevention of the development of this condition remains the best approach for survival.

Homicidal commotio cordis caused by domestic violence: A report of two cases

Commotio cordis is a rare and fatal mechano-electric arrhythmogenic syndrome, occurring mainly during sports activities. The present study describes two cases of sudden death due to homicidal commotio cordis caused violence from an intimate partner. The two decedents were both young women. They suffered from physical abuse by their intimate partner and collapsed immediately after being punched in the precordium. Electrocardiograms were recorded at the hospital and showed ventricular fibrillation in one case. An autopsy was performed in each case, and no structural cardiac damage, evident lesions of other internal organs or underlying diseases were found. Combined with the negative toxicological analysis, it was concluded that the cause of death was commotio cordis due to a blunt force to the anterior chest. To the best of the authors' knowledge, there is no published report on commotio cordis caused by physical abuse from an intimate partner. The accurate diagnosis of the cause of death is emphasised, as it is important for judicial fairness.

Sudden cardiac death while playing Australian Rules football: a retrospective 14 year review

Australian Rules football is a sport which evolved from Gaelic football and which is played by a large number of predominantly male participants in a number of countries. The highest participation rates are in the southern states of Australia. A retrospective review over a period of 14 years identified 14 cases of sudden cardiac death that occurred in individuals while playing the sport. All were male and ranged in age from 13 to 36 years with a mean and median age of 23 years. A spectrum of cardiac causes was identified including coronary artery atherosclerosis, myocarditis, anomalous coronary artery anatomy, arrhythmogenic right ventricular cardiomyopathy, and healed Kawasaki disease. In 5 cases the heart was morphologically normal raising the possibility of a channelopathy. No traumatic deaths were identified. Some of the individuals had experienced symptoms prior to the fatal episode and the role of pre participation screening in reducing mortality is discussed.

Restart the heart

Early bystander cardiopulmonary resuscitation and rapid defibrillation are the most important factors for favourable outcomes after out of hospital cardiac arrest (OHCA)-as the new American Heart Association/European Resuscitation Council (AHA/ERC) guidelines emphasise. The patient in our case was a healthy young man who had a witnessed cardiac arrest due to a chest collision with the goalkeeper during a football match. Basic life support was immediately provided by his teammates until an automated external defibrillator was brought to the scene. Blunt cardiac injury (BCI) may result in injured myocardium or arrhythmias. Ventricular fibrillation due to BCI in absence of structural cardiac disease is one of the main causes of OHCA in young healthy athletes with high mortality rates. We demonstrate important aspects of the recently released guidelines on cardiac arrest and the chain of survival by the leading societies.

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.

Historical Perspectives on Sudden Deaths in Young Athletes With Evolution over 35 Years

Sudden death in young competitive athletes has become a highly visible and substantial issue within cardiovascular medicine of interest both to the general public and to the practicing community. At this time, it is instructive to revisit the evolution of this clinical problem over the past 35 years starting with introduction into the public and medical consciousness by the unexpected sudden deaths of 2 college basketball players within 8 weeks of each other in 1976, 1 with Marfan syndrome and the other with hypertrophic cardiomyopathy. Subsequently, over the next years, a number of elite athletes died suddenly, raising public visibility and awareness of these tragic events: Len Bias, "Pistol" Pete Maravich, Hank Gathers, Reggie Lewis, Kori Stringer, Jason Collier, and Thomas Herrion. Intense interest in these and many other athlete deaths has led to a considerable understanding regarding the demographics, incidence, and causes of these deaths, which include a variety of genetic and/or congenital cardiovascular diseases (most commonly hypertrophic cardiomyopathy), blunt trauma, commotio cordis, and sickle cell trait. Ultimately, initiatives emerged creating consensus guidelines for disqualification versus eligibility decisions, and preparticipation screening to detect unsuspected cardiac abnormalities. This journey of now >3 decades has generated voluminous data and even controversy, but continues to hold great interest in clinical scientists, medical practitioners, and the general public.

Pathophysiology, prevention, and treatment of commotio cordis

Commotio cordis is increasing described and it is now clear that this phenomenon is an important cause of sudden cardiac death on the playing field. Victims are predominantly young, male, and struck in the left chest with a ball. An animal model has been developed and utilized to explore the important variables and mechanism of commotio cordis. Impact during a narrow window of repolarization causes ventricular fibrillation. Other important variables include location, velocity, shape, and hardness of the impact object. Biological characteristics such as gender, pliability of the chest wall, and genetic susceptibility also play a role in commotio cordis. The mechanism of ventricular fibrillation appears to be an increase in heterogeneity of repolarization caused by induced abnormalities of ion channels activated by abrupt increases in left ventricular pressure. In the setting of altered repolarization a trigger of ventricular depolarization (premature ventricular depolarization caused directly by the chest blow) initiates a spiral wave that quickly breaks down into ventricular fibrillation. Prevention of commotio cordis is possible. Improved recognition and resuscitation have led to an improvement in outcome.

Atrial fibrillation induced by commotio cordis secondary to a blunt chest trauma in a teenage boy

Low-energy blunt chest trauma can cause commotio cordis and ventricular fibrillation (VF) in otherwise healthy young individuals. If the chest wall impact occurs during a narrow vulnerable window of ventricular repolarization, the generated premature ventricular impulse can lead to VF and sudden death. Atrial fibrillation (AF) in association with a blunt chest trauma has not yet been reported in a child or adolescent. Our case describes a healthy 16-year-old boy who suffered blunt chest trauma during football practice. He was found to have AF, which resolved in 3 days without any therapy. He did not have any identifiable structural or electrical cardiac abnormality and had no previous history of arrhythmia. We hypothesize that AF, similar to commotio cordis-induced VF, may occur as a result of a blunt chest trauma in healthy young individuals. Animal studies evaluating arrhythmias related to chest wall impact may elucidate the timing and mechanism of AF induced by commotio cordis.

Traumatic Tension Pneumothorax as a Cause of ICD Failure: A Case Report and Review of the Literature

Background. Tension pneumothorax can infrequently cause ventricular arrhythmias and increase the threshold of defibrillation. It should be suspected whenever there is difficulty in defibrillation for a ventricular arrhythmia. Purpose. To report a case of traumatic tension pneumothorax leading to ventricular tachycardia and causing defibrillator failure. Case. A 65-year-old African-American female was brought in to our emergency department complaining of dyspnea after being forced down by cops. She had history of mitral valve replacement for severe mitral regurgitation and biventricular implantable cardioverter defibrillator inserted for nonischemic cardiomyopathy. Shortly after arrival, she developed sustained ventricular tachycardia, causing repetitive unsuccessful ICD shocks. She was intubated and ventricular tachycardia resolved with amiodarone. Chest radiograph revealed large left sided tension pneumothorax which was promptly drained. The patient was treated for congestive heart failure; she was extubated on the third day of admission, and the chest tube was removed. Conclusion. Prompt recognition of tension pneumothorax is essential, by maintaining a high index of suspicion in patients with an increased defibrillation threshold causing ineffective defibrillations.

[Cardiac disease at risk in the young athlete]

Physical training significantly reduces all cause mortality in the general population. Eligibility for competitive sport participation in athletes with cardiovascular diseases is based on recommendations. Incidence of sudden cardiac death in young athletes is low (0.5 to 2/100,000 athletes/year). The most common cardiac diseases at risk are hypertrophic cardiomyopathies, congenital coronary arteries abnormalities, arrhythmogenic right ventricular cardiomyopathy and acute myocarditis. Pre-participation screening is based on the cardiovascular evaluation, including ECG (repeated every 3years since the age of 12 and every 5years since the age of 20 to the age of 35). Some events are unpredictable (idiopathic ventricular fibrillation, sudden death related to congenital coronary arteries abnormalities or commotio cordis). A better access to public defibrillation is needed.