Commotio cordis

Last updated

Commotio cordis
Heart-thorax-gray.gif
Human adult thorax, showing the outline of the heart in red. The sensitive zone for mechanical induction of heart rhythm disturbances lies between the second and the fourth ribs, to the left of the sternum.
Specialty Cardiology
Complications Ventricular fibrillation, quickly followed by cardiac arrest and (if not treated) death
Usual onsetWithin seconds after impact
CausesSufficient blow to the precordium between 10 and 40 milliseconds before the peak of the T wave portion of normal cardiac rhythm
Risk factors Coronary ischemia can reduce amount of impact energy required to trigger
Treatment CPR, defibrillation
Prognosis Survival rate drops to <5% if not resuscitated within 3 minutes
FrequencyExtremely rare

Commotio cordis (Latin, "agitation or disruption of the heart") is a rare disruption of heart rhythm that occurs as a result of a blow to the area directly over the heart (the precordial region) at a critical instant during the cycle of a heartbeat. [1] The condition is 97% fatal if not treated within three minutes. [2] This sudden rise in intracavitary pressure leads to disruption of normal heart electrical activity, followed instantly by ventricular fibrillation, complete disorganization of the heart's pumping function, and cardiac arrest. It is not caused by mechanical damage to the heart muscle or surrounding organs and is not the result of heart disease.

Contents

Its incidence in the United States is fewer than 20 cases per year, often occurring in boys participating in sports, most commonly in baseball when a ball strikes a player in the chest.

Commotio cordis can occur only upon impact within a narrow window of about 40 milliseconds in the cardiac electrical cycle, explaining why it is so rare. [1]

If cardiopulmonary resuscitation (CPR) combined with use of an on-site automated external defibrillator is employed within three minutes of the impact, survival from commotio cordis can be as high as 58 percent. [3]

Assessment

There are only 10–20 cases annually in the United States. [1] These cases occur mostly in boys and young men (mean age 15), usually during sports participation. [1] It occurs most frequently in baseball when the hard ball strikes an unprotected chest, although there have been cases of commotio cordis in players using a chest protector. [1] It is usually caused by a projectile, but can also be caused by a blow from another player's elbow or other body part. Being less developed, the thorax of an adolescent is likely more prone to this injury than a mature adult. [1]

Over a period of assessment from 2006–2012, the survival rate was 58 percent, which was an improvement over the years 1993–2006 when only 34 percent of victims survived. [3] [4] This increase is likely due to prompt CPR, access to defibrillation, and higher public awareness of this phenomenon. [1] [3]

Potential for sudden death

Due to ventricular fibrillation and resultant cessation of the cardiac output to vital organs, commotio cordis has a high fatality rate, indicated by two studies to be 72–75 percent, with survival decreasing substantially if effective resuscitation was not performed within three minutes of the impact event. [3] [2] In a United States timeline analysis, survival was only ten percent over the years 1970–1993, while during 1994–2012, survival improved to 34 percent. [3] A 2009 paper reported that survival drops to 3% when resuscitation is delayed beyond 3 minutes. [2]

Higher survival rates correlated with immediate resuscitation by using CPR and an on-site automated external defibrillator—the survival rate was forty percent if resuscitation was performed within three minutes of the impact injury, contrasted with only five percent survival if resuscitation was delayed to more than three minutes after the impact. [3] During the early 21st century, survival rates continued to improve to 58 percent of cases. [3]

Causes

Sports

Commotio cordis is a very rare event, but nonetheless it is often considered when an athlete presents with sudden cardiac death. Some of the sports which have a risk for this cause of trauma are baseball, American football, association football (soccer), ice hockey, polo, rugby football, cricket, softball, pelota, lacrosse, boxing, professional wrestling, hurling and martial arts (see Touch of Death). Children are especially vulnerable, possibly due to the mechanical properties of their thoracic skeleton. [1] [5] From 1996 to spring 2007, the US National Commotio Cordis Registry had 188 cases recorded, with about half occurring during organized sports. [6] Almost all (96%) of the victims were male, the mean age of the victims during that period was 14.7 years, and fewer than one in five survived the incident. [6]

Baseball is the most common sport in which commotio cordis occurs in regions where it is played, particularly among teenage boys who are batting or playing the positions of pitcher or catcher. [1] Commotio cordis may occur in other sports via impacts to the chest by elbows or heads. [1] It has also been reported outside of sports when there is sudden impact to the chest wall by hard objects or fists. [1]

St. Louis Blues defenceman Chris Pronger experienced commotio cordis during a playoff game on May 11, 1998 against the Detroit Red Wings when a slapshot from Dmitri Mironov struck his chest. Pronger went into cardiac arrest and was unconscious for 20 seconds while he was resuscitated by members of both the Blues' and Red Wings' training staff. [7] [8] Pronger made a full recovery after an overnight stay at Henry Ford Hospital in Detroit and would be cleared to play again four days later. The incident ultimately had a negligible effect on his career, which lasted until 2011. Another high-profile incident occurred on January 3, 2023 during Monday Night Football when Buffalo Bills safety Damar Hamlin experienced commotio cordis after Cincinnati Bengals wide receiver Tee Higgins's helmet struck him in the chest as he was making a tackle. [9] Hamlin collapsed and went into cardiac arrest, and his life was saved by the Bills' training staff administering CPR and employing an automated external defibrillator (AED). [10]

Impact factors

In experimental animal models in pigs studying impacts by a hard ball to the chest wall, impacts that occurred directly over the center of the left ventricle, where there is no overlying lung tissue, were the most likely to cause ventricular fibrillation. [1] Impacts not over the heart did not cause ventricular fibrillation. [1] Ventricular fibrillation was more easily induced in smaller, leaner animals. [1]

The velocity of the impact by a hard object is a critical factor for the onset of commotio cordis: impacts at 40 miles per hour (64 kilometres per hour) were the most likely to cause ventricular fibrillation in an animal model. [1] At velocities of 20 miles per hour (32 km/h), ventricular fibrillation did not occur.

Impact energies of at least 50 joules (37 foot-pounds force ) may cause cardiac arrest when applied at the right time and location of the precordium of an adult. [11] The 50-joule threshold, however, can be considerably lower when the victim's heart is under ischemic conditions, such as in coronary artery insufficiency. [11] Contusion of the heart, involving possible rupture of a heart chamber or damage to a heart valve as may occur in a violent vehicle accident, may be called contusio cordis (from Latin for "bruising of the heart"), but is unrelated to commotio cordis. [1]

Other situations

Commotio cordis may also occur in other situations, such as in children who are physically abused, cases of torture, and frontal collisions of motor vehicles (the impact of the steering wheel against the thorax, although this has decreased substantially with the use of safety belts and air bags). In one fatality, the impact to the chest was the result of an exploding whipped cream canister. [12]

In contrast, the precordial thump (hard blows given over the precordium with a closed fist to revert cardiac arrest) is a sanctioned procedure for emergency resuscitation by trained health professionals witnessing a monitored arrest when no equipment is at hand, endorsed by the latest guidelines of the International Liaison Committee on Resuscitation. It has been discussed controversially, as—in particular in severe hypoxia—it may cause the opposite effect (i.e., a worsening of rhythm—commotio cordis). In a normal adult, the energy range involved in the precordial thump is five to ten times below that associated with commotio cordis. [11]

Mechanism

Electrocardiograph: the portion of normal sinus rhythm during which commotio cordis is a risk if a severe chest impact occurs within the narrow vulnerability window Commotio Cordis Risk Zone.jpg
Electrocardiograph: the portion of normal sinus rhythm during which commotio cordis is a risk if a severe chest impact occurs within the narrow vulnerability window

The deviation of commotio cordis from the normal electrical rhythm of the heart is assessed scientifically in laboratory studies by analysis of the electrocardiograph (ECG) T wave (see ECG image). [1] Only chest impacts occurring on a narrow band of the ECG during the upslope of the T wave (40 milliseconds (ms) before the peak of the T wave to the instant of the actual peak) will cause the ventricular fibrillation of commotio cordis, with an increased probability occurring when an impact happens from 30 to 10 ms before the peak of the T wave. [1]

These factors influence the onset of commotio cordis: [1]

The small window of vulnerability in the cardiac electrical cycle explains why it is a rare event. [1] Considering that the total cardiac cycle has a duration of one second (for a base heart rate of 60 beats per minute), the probability of impact trauma within the window of vulnerability is 1–3 percent only. [1]

The cellular mechanisms of commotio cordis are not fully understood. However, it is widely recognized that it may be related to the mechanical impact, or stretch, on the myocardial tissue cell membranes. This impact is believed to activate the stretch-activated, pressure–sensitive proteins called ion channels. [1] Changes in ion channels lead to altered repolarization in the heart's electrical activity, which in some cases, if occurring right at the trailing edge of a previous electrical cycle, can induce ventricular fibrillation, also known as stretch-induced VF. [1] [13] [14] Since the trailing edge of the preceding electrical cycle travels over the ventricular surface, the critical window for mechanical induction of ventricular fibrillation varies locally across the ventricle. [13]

Risk reduction

For some sports participation in which hard balls are used, such as baseball or lacrosse, softer, more pliable balls may reduce the impact trauma causing commotio cordis. [1] The shape of the impact object may be modified for some conditions, such as by using a flat object – which did not induce ventricular fibrillation upon impact in preliminary research – whereas spherical objects with smaller radii were more likely to induce ventricular fibrillation. [1] Safety baseballs having lower degrees of hardness, e.g., softer, pliable and elastic balls used for Tee-ball or more pliable baseballs for older age groups, may reduce the risk of commotio cordis. [1]

The risk of impact may be reduced by improved coaching techniques, such as teaching young batters to turn away from the ball to avoid errant pitches in baseball. Defensive players in lacrosse and hockey may be coached to avoid using their chest to block the ball or puck. Starting in 2017, high school lacrosse players are penalized, and play is stopped immediately if they enter their own goal crease with the apparent intent of blocking shots or acting as goalkeeper. [15]

Chest protectors and vests are designed to reduce trauma from blunt bodily injury, but many commercially available chest protectors do not offer protection from commotio cordis and may offer a false sense of security. [1] A 2010 study found that almost 20 percent of the victims in competitive football, baseball, lacrosse, and hockey were wearing protectors. [5] A 2017 study found that specially-designed chest protectors do reduce the risk of commotio cordis, but do not offer 100 percent protection. [16]

In 2017, the National Operating Committee on Standards for Athletic Equipment (NOCSAE) finalized a new standard outlining outlining performance requirements and test methods for chest protectors used in baseball and lacrosse, ND200 Standard Test Method and Performance Specification Used in Evaluating the Performance Characteristics of Chest Protectors for Commotio Cordis. [17] Beginning in 2021, US Lacrosse made chest protectors that meet the NOCSAE ND200 standard a requirement for all goalies, and expanded coverage in 2022 to require all players to wear such a chest protector. [18] In 2018, the National Federation of State High School Associations (NFHS) changed their baseball rules to require the catcher to wear a chest protector that meets the NOCSAE ND200 standard requirements. [19]

Treatment

Defibrillator training kit Medtronic aed training kit.jpg
Defibrillator training kit

Automated external defibrillators (AED) and prompt CPR helped to increase the survival rate to 58 percent. [3] CPR and defibrillation must be started urgently (within three minutes) to avoid death of the person impacted. [3] To assure life-saving procedures and equipment are in place at events where impact injuries are possible, clinical recommendations state that "communities and school districts reexamine the need for accessible automatic defibrillators and CPR-trained coaches at organized sporting events for children." [20]

Several people have been charged and convicted for the deaths of victims of commotio cordis, even when the blows rendered were never given with an intent to kill. [21] In 1992, Italian hockey player Miran Schrott died after a blow to his chest from the stick of Italian-Canadian player Jimmy Boni. Boni was charged with culpable homicide, and eventually pleaded guilty to manslaughter, paying a $1,300 fine and $175,000 restitution to Schrott's family. [22]

See also

Related Research Articles

<span class="mw-page-title-main">Cardiac arrest</span> Sudden failure of heart beat

Cardiac arrest, also known as sudden cardiac arrest, is when the heart suddenly and unexpectedly stops beating. As a result, blood cannot properly circulate around the body and there is diminished blood flow to the brain and other organs. When the brain does not receive enough blood, this can cause a person to lose consciousness. Coma and persistent vegetative state may result from cardiac arrest. Cardiac arrest is also identified by a lack of central pulses and abnormal or absent breathing.

<span class="mw-page-title-main">Cardiopulmonary resuscitation</span> Emergency procedure for cardiac arrest

Cardiopulmonary resuscitation (CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation, or mouth to mouth in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person who is in cardiac arrest. It is recommended for those who are unresponsive with no breathing or abnormal breathing, for example, agonal respirations.

<span class="mw-page-title-main">Cardioversion</span> Conversion of a cardiac arrhythmia to a normal rhythm using an electrical shock or medications

Cardioversion is a medical procedure by which an abnormally fast heart rate (tachycardia) or other cardiac arrhythmia is converted to a normal rhythm using electricity or drugs. Synchronized electrical cardioversion uses a therapeutic dose of electric current to the heart at a specific moment in the cardiac cycle, restoring the activity of the electrical conduction system of the heart. Pharmacologic cardioversion, also called chemical cardioversion, uses antiarrhythmia medication instead of an electrical shock.

<span class="mw-page-title-main">Defibrillation</span> Treatment for life-threatening cardiac arrhythmias

Defibrillation is a treatment for life-threatening cardiac arrhythmias, specifically ventricular fibrillation (V-Fib) and non-perfusing ventricular tachycardia (V-Tach). A defibrillator delivers a dose of electric current to the heart. Although not fully understood, this process depolarizes a large amount of the heart muscle, ending the arrhythmia. Subsequently, the body's natural pacemaker in the sinoatrial node of the heart is able to re-establish normal sinus rhythm. A heart which is in asystole (flatline) cannot be restarted by a defibrillator; it would be treated only by cardiopulmonary resuscitation (CPR) and medication, and then by cardioversion or defibrillation if it converts into a shockable rhythm.

<span class="mw-page-title-main">Ventricular fibrillation</span> Rapid quivering of the ventricles of the heart

Ventricular fibrillation is an abnormal heart rhythm in which the ventricles of the heart quiver. It is due to disorganized electrical activity. Ventricular fibrillation results in cardiac arrest with loss of consciousness and no pulse. This is followed by sudden cardiac death in the absence of treatment. Ventricular fibrillation is initially found in about 10% of people with cardiac arrest.

<span class="mw-page-title-main">Asystole</span> Medical condition of the heart

Asystole is the absence of ventricular contractions in the context of a lethal heart arrhythmia. Asystole is the most serious form of cardiac arrest and is usually irreversible. Also referred to as cardiac flatline, asystole is the state of total cessation of electrical activity from the heart, which means no tissue contraction from the heart muscle and therefore no blood flow to the rest of the body.

<span class="mw-page-title-main">Automated external defibrillator</span> Portable electronic medical device

An automated external defibrillator or automatic electronic defibrillator (AED) is a portable electronic device that automatically diagnoses the life-threatening cardiac arrhythmias of ventricular fibrillation (VF) and pulseless ventricular tachycardia, and is able to treat them through defibrillation, the application of electricity which stops the arrhythmia, allowing the heart to re-establish an effective rhythm.

<span class="mw-page-title-main">Implantable cardioverter-defibrillator</span> Medical device

An implantable cardioverter-defibrillator (ICD) or automated implantable cardioverter defibrillator (AICD) is a device implantable inside the body, able to perform defibrillation, and depending on the type, cardioversion and pacing of the heart. The ICD is the first-line treatment and prophylactic therapy for patients at risk for sudden cardiac death due to ventricular fibrillation and ventricular tachycardia.

<span class="mw-page-title-main">Ventricular tachycardia</span> Medical condition of the heart

Ventricular tachycardia is a cardiovascular disorder in which fast heart rate occurs in the ventricles of the heart. Although a few seconds of VT may not result in permanent problems, longer periods are dangerous; and multiple episodes over a short period of time are referred to as an electrical storm. Short periods may occur without symptoms, or present with lightheadedness, palpitations, shortness of breath, chest pain, and decreased level of consciousness. Ventricular tachycardia may lead to coma and persistent vegetative state due to lack of blood and oxygen to the brain. Ventricular tachycardia may result in ventricular fibrillation (VF) and turn into cardiac arrest. This conversion of the VT into VF is called the degeneration of the VT. It is found initially in about 7% of people in cardiac arrest.

Precordial thump is a medical procedure used in the treatment of ventricular fibrillation or pulseless ventricular tachycardia under certain conditions. The procedure has a very low success rate, but may be used in those with witnessed, monitored onset of one of the "shockable" cardiac rhythms if a defibrillator is not immediately available. It should not delay cardiopulmonary resuscitation (CPR) and defibrillation, nor should it be used in those with unwitnessed out-of-hospital cardiac arrest.

Pulseless electrical activity (PEA) is a form of cardiac arrest in which the electrocardiogram shows a heart rhythm that should produce a pulse, but does not. Pulseless electrical activity is found initially in about 20% of out-of-hospital cardiac arrests and about 50% of in-hospital cardiac arrests.

A blunt cardiac injury is an injury to the heart as the result of blunt trauma, typically to the anterior chest wall. It can result in a variety of specific injuries to the heart, the most common of which is a myocardial contusion, which is a term for a bruise (contusion) to the heart after an injury. Other injuries which can result include septal defects and valvular failures. The right ventricle is thought to be most commonly affected due to its anatomic location as the most anterior surface of the heart. Myocardial contusion is not a specific diagnosis and the extent of the injury can vary greatly. Usually, there are other chest injuries seen with a myocardial contusion such as rib fractures, pneumothorax, and heart valve injury. When a myocardial contusion is suspected, consideration must be given to any other chest injuries, which will likely be determined by clinical signs, tests, and imaging.

The chain of survival refers to a series of actions that, properly executed, reduce the mortality associated with sudden cardiac arrest. Like any chain, the chain of survival is only as strong as its weakest link. The six interdependent links in the chain of survival are early recognition of sudden cardiac arrest and access to emergency medical care, early CPR, early defibrillation, early advanced cardiac life support, and physical and emotional recovery. The first three links in the chain can be performed by lay bystanders, while the second three links are designated to medical professionals. Currently, between 70 and 90% of cardiac arrest patients die before they reach the hospital. However, a cardiac arrest does not have to be lethal if bystanders can take the right steps immediately.

The history of cardiopulmonary resuscitation (CPR) can be traced as far back as the literary works of ancient Egypt. However, it was not until the 18th century that credible reports of cardiopulmonary resuscitation began to appear in the medical literature.

<span class="mw-page-title-main">William B. Kouwenhoven</span>

William Bennet Kouwenhoven, also known as the "Father of Cardiopulmonary Resuscitation," is famous for his contributions to the development of the closed-chest cardiac massage and his invention of the cardiac defibrillator. After obtaining his doctorate degree in engineering from the Karlsruhe Technische Hochschule in Germany, Kouwenhoven began his career as the dean at the Johns Hopkins University in Baltimore. Kouwenhoven focused his research mainly on improving and saving lives of patients through the application of electricity. With the help and cooperation of the Johns Hopkins School of Medicine's Department of Surgery and an Edison Electric Institute grant, Kouwenhoven was able to develop a closed-chest defibrillator. For his contributions to the field of medical science, he became the first ever recipient of an honorary degree conferred by the Johns Hopkins School of Medicine. Two years before his death, Kouwenhoven was also awarded the Albert Lasker Award for Clinical Medical Research.

Pediatric advanced life support (PALS) is a course offered by the American Heart Association (AHA) for health care providers who take care of children and infants in the emergency room, critical care and intensive care units in the hospital, and out of hospital. The course teaches healthcare providers how to assess injured and sick children and recognize and treat respiratory distress/failure, shock, cardiac arrest, and arrhythmias.

<span class="mw-page-title-main">Arrhythmia</span> Group of medical conditions characterized by irregular heartbeat

Arrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per minute in adults – is called tachycardia, and a resting heart rate that is too slow – below 60 beats per minute – is called bradycardia. Some types of arrhythmias have no symptoms. Symptoms, when present, may include palpitations or feeling a pause between heartbeats. In more serious cases, there may be lightheadedness, passing out, shortness of breath, chest pain, or decreased level of consciousness. While most cases of arrhythmia are not serious, some predispose a person to complications such as stroke or heart failure. Others may result in sudden death.

Return of spontaneous circulation (ROSC) is the resumption of a sustained heart rhythm that perfuses the body after cardiac arrest. It is commonly associated with significant respiratory effort. Signs of return of spontaneous circulation include breathing, coughing, or movement and a palpable pulse or a measurable blood pressure. Someone is considered to have sustained return of spontaneous circulation when circulation persists and cardiopulmonary resuscitation has ceased for at least 20 consecutive minutes.

<span class="mw-page-title-main">Celivarone</span> Experimental drug being tested for use in pharmacological antiarrhythmic therapy

Celivarone is an experimental drug being tested for use in pharmacological antiarrhythmic therapy. Cardiac arrhythmia is any abnormality in the electrical activity of the heart. Arrhythmias range from mild to severe, sometimes causing symptoms like palpitations, dizziness, fainting, and even death. They can manifest as slow (bradycardia) or fast (tachycardia) heart rate, and may have a regular or irregular rhythm.

<span class="mw-page-title-main">Rearrest</span>

Rearrest is a phenomenon that involves the resumption of a lethal cardiac dysrhythmia after successful return of spontaneous circulation (ROSC) has been achieved during the course of resuscitation. Survival to hospital discharge rates are as low as 7% for cardiac arrest in general and although treatable, rearrest may worsen these survival chances. Rearrest commonly occurs in the out-of-hospital setting under the treatment of health care providers.

References

  1. 1 2 3 Palacio, Luis E.; Link, Mark S. (March 2009). "Commotio Cordis". Sports Health: A Multidisciplinary Approach. 1 (2): 174–179. doi:10.1177/1941738108330972. ISSN   1941-7381. PMC   3445066 . PMID   23015869.
  2. 1 2 3 4 5 6 7 8 9 Maron, Barry J.; Haas, Tammy S.; Ahluwalia, Aneesha; Garberich, Ross F.; Estes, N. A. Mark; Link, Mark S. (February 2013). "Increasing survival rate from commotio cordis". Heart Rhythm. 10 (2): 219–223. doi:10.1016/j.hrthm.2012.10.034. ISSN   1556-3871. PMID   23107651.
  3. ↑ Abrunzo TJ (November 1991). "Commotio cordis. The single, most common cause of traumatic death in youth baseball". American Journal of Diseases of Children. 145 (11): 1279–1282. doi:10.1001/archpedi.1991.02160110071023. PMID   1951221. S2CID   31217442.
  4. 1 2 Maron BJ, Estes NA (March 2010). "Commotio cordis". The New England Journal of Medicine. 362 (10): 917–927. doi:10.1056/NEJMra0910111. PMID   20220186.
  5. 1 2 "Position Statement on Commotio Cordis". US Lacrosse. January 2008. Archived from the original on 23 February 2017. Retrieved 22 February 2017.
  6. ↑ Patrick, Dan (19 March 2001). "Outtakes: Chris Pronger (uncut)". ESPN. Retrieved 6 January 2023.
  7. ↑ Belson, Ken; Blinder, Alan; Stein, Robin (5 January 2023). "'We're Going to Need Everybody': Recordings Captured Response to N.F.L. Crisis". The New York Times. ISSN   0362-4331 . Retrieved 6 January 2023.
  8. ↑ "Bills say Hamlin suffered cardiac arrest in game". ESPN.com. 3 January 2023. Retrieved 9 May 2023.
  9. ↑ "What is commotio cordis, which NFL player Damar Hamlin says stopped his heart?". www.heart.org. Retrieved 9 May 2023.
  10. 1 2 3 Kohl P, Sachs F & Franz M (eds): Cardiac Mechano-Electric Feedback and Arrhythmias: from Pipette to Patient. Elsevier (Saunders), Philadelphia 2005.
  11. ↑ Barnes, Zahra. "Fitness Blogger Rebecca Burger Died After a Whipped Cream Dispenser Exploded". SELF. Retrieved 14 July 2017.
  12. 1 2 Quinn, T. Alexander; Jin, Honghua; Lee, Peter; Kohl, Peter (9 August 2017). "Mechanically Induced Ectopy via Stretch-Activated Cation-Nonselective Channels Is Caused by Local Tissue Deformation and Results in Ventricular Fibrillation if Triggered on the Repolarization Wave Edge (Commotio Cordis)". Circulation: Arrhythmia and Electrophysiology. 10 (8): e004777. doi:10.1161/CIRCEP.116.004777. ISSN   1941-3149. PMC   5555388 . PMID   28794084.
  13. ↑ Quinn, T. Alexander; Kohl, Peter (1 January 2021). "Cardiac Mechano-Electric Coupling: Acute Effects of Mechanical Stimulation on Heart Rate and Rhythm". Physiological Reviews. 101 (1): 37–92. doi: 10.1152/physrev.00036.2019 . ISSN   0031-9333. PMID   32380895. S2CID   218554597.
  14. ↑ Rule 4.18.4, 2018 Boys' Lacrosse Rule Book. Indianapolis, Indiana: National Federation of State High School Associations. 2018. p. 47.
  15. ↑ Kumar, Kartik; Mandleywala, Swati N.; Gannon, Michael P.; et al. (2017). "Development of a Chest Wall Protector Effective in Preventing Sudden Cardiac Death by Chest Wall Impact (Commotio Cordis)". Clinical Journal of Sport Medicine. 27 (1): 26–30. doi:10.1097/JSM.0000000000000297. PMC   5181132 . PMID   27014942.
  16. ↑ "NOCSAE Finalizes First-Ever Football Helmet Standard to Address Concussion Risks from Rotational Forces and First Chest Protector Standard for Commotio Cordis". NOCSAE. Retrieved 1 April 2024.{{cite web}}: CS1 maint: url-status (link)
  17. ↑ "Heart to Heart: NOCSAE, USL Work to Reduce Risk of Commtio Cordis". USA Lacrosse. Retrieved 1 April 2024.{{cite web}}: CS1 maint: url-status (link)
  18. ↑ "Baseball Rules Changes - 2018". NFHS. Retrieved 1 April 2024.{{cite web}}: CS1 maint: url-status (link)
  19. ↑ Salib EA, Cyran SE, Cilley RE, Maron BJ, Thomas NJ (December 2005). "Efficacy of bystander cardiopulmonary resuscitation and out-of-hospital automated external defibrillation as life-saving therapy in commotio cordis". The Journal of Pediatrics. 147 (6): 863–866. doi: 10.1016/j.jpeds.2005.07.041 . PMID   16356450.
  20. ↑ Maron BJ, Mitten MJ, Greene Burnett C (January 2002). "Criminal consequences of commotio cordis". The American Journal of Cardiology. 89 (2): 210–213. doi:10.1016/S0002-9149(01)02202-0. PMID   11792344.
  21. ↑ Maki, Allan (28 September 2007). "Darcy Robinson's death brings shock". The Globe and Mail. Retrieved 29 February 2016.

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.