Commotio cordis
Encyclopedia
Commotio cordis is a 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 time during the cycle of a heart beat. It is a form of ventricular fibrillation
, not mechanical damage to the heart muscle or surrounding organs, and not the result of heart disease. The fatality rate is about 65%. It can sometimes, but not always, be reversed by defibrillation.
Commotio cordis occurs mostly in boys and young men (average age 15), usually during sport
s, most often baseball, often despite a chest protector. It is most often caused by a projectile, but can also be caused by the blow of an elbow or other body part. Being less developed, the thorax of an adolescent is likely more prone to this injury given the circumstances.
The phenomenon was confirmed experimentally in the 1930s, with research in anaesthetized rabbit
s, cat
s and dog
s.
, association football, ice hockey
, polo
, rugby football
, cricket
, softball
, pelota, fencing
, lacrosse
, boxing
, karate
, kung fu and other martial arts
. Child
ren are especially vulnerable, possibly due to the mechanical properties of their thoracic skeleton
. From 1996 to spring 2007, the USA
National Commotio Cordis Registry had 188 cases recorded, with about half occurring during organized sports Almost all (96%) of the victims were male, the mean age of the victims during that period was 14.7 years, and fewer than 1 in 5 survived the incident.
.
, frontal collisions of motor vehicle
s (the impact of the steering wheel against the thorax, although this has decreased substantially with the use of safety belts and air bags).
In contrast, the precordial thump
(hard blows given over the precordium with a closed fist in order 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 5-10 times below that associated with commotio cordis.
The small window of vulnerability explains why it is a rare event. Considering that the total cardiac cycle has a duration of 1000 milliseconds (for a base cardiac frequency of 60 beats per minute), the probability of a mechanical trauma within the window of vulnerability is 1 to 3% only. That also explains why the heart becomes more vulnerable when it is physically strained by sports activities:
The cellular
mechanisms of commotio cordis are still poorly understood, but probably related to the activation of mechano-sensitive proteins, ion channels.
It is estimated that impact energies of at least 50 joule
s are required to cause cardiac arrest, when applied in the right time and spot of the precordium of an adult. Impacts of up to 130 joules have already been measured with hockey puck
s and lacrosse balls, 450 joules in karate punches and 1028 joules in boxer Rocky Marciano
's punch. The 50 joule threshold, however, can be considerably lowered when the victim's heart is under ischemic
conditions, such as in coronary artery insufficiency.
There is also an upper limit of impact energy applied to the heart; too much energy will create structural damage to the heart muscle as well as causing electrical upset. This condition is referred to as contusio cordis (from Latin for bruising of the heart). On isolated guinea pig
hearts, as little as 5 mJ was needed to induce release of creatine kinase
, a marker for muscle cell damage. Obviously one should take into account that this figure does not include the dissipation of energy through the chest wall, and is not scaled up for humans, but it is indicative that relatively small amounts of energy are required to reach the heart before physical damage is done.
s. Defibrillation must be started within 3 minutes, and can only sometimes restore heart activity. Commotio cordis is the leading cause of fatalities in youth baseball in the US, with 2 to 3 deaths per year. It has been recommended that "communities and school district
s reexamine the need for accessible automatic defibrillators and cardiopulmonary resuscitation-trained coaches at organized sporting events for children."
Chest protectors and vests are designed to reduce trauma from blunt bodily injury, but this does not offer protection from commotio cordis and may offer a false sense of security. Almost 20% of the victims in competitive football, baseball, lacrosse and hockey were wearing protectors. This ineffectiveness has been confirmed by animal studies. Development of adequate chest protectors may prove difficult.
game in 2011.
Austin Sergeev, an 11-year old, died during a flag football game in 2008 in Lake Oswego, OR.
in cases involving insufficient and slow medical help to athletes who underwent commotio cordis during sports events, as well as in cases of intentional delivery of contusive blows.
Heart Rhythm
Heart Rhythm is a peer-reviewed medical journal that covers the study and management of cardiac arrhythmia. It is the official journal of the Heart Rhythm Society and the Cardiac Electrophysiology Society...
that occurs as a result of a blow to the area directly over the heart (the precordial region
Precordium
In anatomy, the precordium is the portion of the body over the heart and lower chest.Precordial chest pain can be an indication of a variety of illnesses, including costochondritis and viral pericarditis....
), at a critical time during the cycle of a heart beat. It is a form of ventricular fibrillation
Ventricular fibrillation
Ventricular fibrillation is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricles in the heart, making them quiver rather than contract properly. Ventricular fibrillation is a medical emergency and most commonly identified arrythmia in cardiac arrest...
, not mechanical damage to the heart muscle or surrounding organs, and not the result of heart disease. The fatality rate is about 65%. It can sometimes, but not always, be reversed by defibrillation.
Commotio cordis occurs mostly in boys and young men (average age 15), usually during sport
Sport
A Sport is all forms of physical activity which, through casual or organised participation, aim to use, maintain or improve physical fitness and provide entertainment to participants. Sport may be competitive, where a winner or winners can be identified by objective means, and may require a degree...
s, most often baseball, often despite a chest protector. It is most often caused by a projectile, but can also be caused by the blow of an elbow or other body part. Being less developed, the thorax of an adolescent is likely more prone to this injury given the circumstances.
The phenomenon was confirmed experimentally in the 1930s, with research in anaesthetized rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
s, cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s and dog
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
s.
Incidence
Commotio cordis is a very rare event, but nonetheless 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 baseballBaseball
Baseball is a bat-and-ball sport played between two teams of nine players each. The aim is to score runs by hitting a thrown ball with a bat and touching a series of four bases arranged at the corners of a ninety-foot diamond...
, association football, ice hockey
Ice hockey
Ice hockey, often referred to as hockey, is a team sport played on ice, in which skaters use wooden or composite sticks to shoot a hard rubber puck into their opponent's net. The game is played between two teams of six players each. Five members of each team skate up and down the ice trying to take...
, polo
Polo
Polo is a team sport played on horseback in which the objective is to score goals against an opposing team. Sometimes called, "The Sport of Kings", it was highly popularized by the British. Players score by driving a small white plastic or wooden ball into the opposing team's goal using a...
, rugby football
Rugby football
Rugby football is a style of football named after Rugby School in the United Kingdom. It is seen most prominently in two current sports, rugby league and rugby union.-History:...
, cricket
Cricket
Cricket is a bat-and-ball game played between two teams of 11 players on an oval-shaped field, at the centre of which is a rectangular 22-yard long pitch. One team bats, trying to score as many runs as possible while the other team bowls and fields, trying to dismiss the batsmen and thus limit the...
, softball
Softball
Softball is a bat-and-ball sport played between two teams of 10 to 14 players. It is a direct descendant of baseball although there are some key differences: softballs are larger than baseballs, and the pitches are thrown underhand rather than overhand...
, pelota, fencing
Fencing
Fencing, which is also known as modern fencing to distinguish it from historical fencing, is a family of combat sports using bladed weapons.Fencing is one of four sports which have been featured at every one of the modern Olympic Games...
, lacrosse
Lacrosse
Lacrosse is a team sport of Native American origin played using a small rubber ball and a long-handled stick called a crosse or lacrosse stick, mainly played in the United States and Canada. It is a contact sport which requires padding. The head of the lacrosse stick is strung with loose mesh...
, boxing
Boxing
Boxing, also called pugilism, is a combat sport in which two people fight each other using their fists. Boxing is supervised by a referee over a series of between one to three minute intervals called rounds...
, karate
Karate
is a martial art developed in the Ryukyu Islands in what is now Okinawa, Japan. It was developed from indigenous fighting methods called and Chinese kenpō. Karate is a striking art using punching, kicking, knee and elbow strikes, and open-handed techniques such as knife-hands. Grappling, locks,...
, kung fu and other martial arts
Martial arts
Martial arts are extensive systems of codified practices and traditions of combat, practiced for a variety of reasons, including self-defense, competition, physical health and fitness, as well as mental and spiritual development....
. Child
Child
Biologically, a child is generally a human between the stages of birth and puberty. Some vernacular definitions of a child include the fetus, as being an unborn child. The legal definition of "child" generally refers to a minor, otherwise known as a person younger than the age of majority...
ren are especially vulnerable, possibly due to the mechanical properties of their thoracic skeleton
Thorax
The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...
. From 1996 to spring 2007, the USA
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
National Commotio Cordis Registry had 188 cases recorded, with about half occurring during organized sports Almost all (96%) of the victims were male, the mean age of the victims during that period was 14.7 years, and fewer than 1 in 5 survived the incident.
.
Other situations
Commotio cordis may also occur in other situations, such as in children who are punished with blows over the precordium, cases of tortureTorture
Torture is the act of inflicting severe pain as a means of punishment, revenge, forcing information or a confession, or simply as an act of cruelty. Throughout history, torture has often been used as a method of political re-education, interrogation, punishment, and coercion...
, frontal collisions of motor vehicle
Motor vehicle
A motor vehicle or road vehicle is a self-propelled wheeled vehicle that does not operate on rails, such as trains or trolleys. The vehicle propulsion is provided by an engine or motor, usually by an internal combustion engine, or an electric motor, or some combination of the two, such as hybrid...
s (the impact of the steering wheel against the thorax, although this has decreased substantially with the use of safety belts and air bags).
In contrast, the precordial thump
Precordial thump
The precordial thump is a medical procedure that may used by healthcare professionals, to respond to ventricular fibrillation or ventricular tachycardia under certain conditions. The procedure is outside the scope of first-aid treatment and requires, at minimum, training in advanced cardiac life...
(hard blows given over the precordium with a closed fist in order to revert cardiac arrest
Cardiac arrest
Cardiac arrest, is the cessation of normal circulation of the blood due to failure of the heart to contract effectively...
) 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 5-10 times below that associated with commotio cordis.
Mechanism of injury
The following factors influence the chance of commotio cordis:- Direction of impact over the precordium (precise area, angle of impact)
- Total applied energy (area of impact versus energy, i.e., the mass of the projectile multiplied half the square of its velocity)
- Impact occurring within a specific 10-30 millisecond portion of the cardiac cycle. This period occurs in the ascending phase of the T wave, when the ventricular myocardium is repolarizing, moving from systoleSystole (medicine)Systole is the contraction of the heart. Used alone, it usually means the contraction of the left ventricle.In all mammals, the heart has 4 chambers. The left and right ventricles pump together. The atria and ventricles pump in sequence...
to diastoleDiastoleDiastole is the period of time when the heart fills with blood after systole . Ventricular diastole is the period during which the ventricles are relaxing, while atrial diastole is the period during which the atria are relaxing...
(relaxation).
The small window of vulnerability explains why it is a rare event. Considering that the total cardiac cycle has a duration of 1000 milliseconds (for a base cardiac frequency of 60 beats per minute), the probability of a mechanical trauma within the window of vulnerability is 1 to 3% only. That also explains why the heart becomes more vulnerable when it is physically strained by sports activities:
- The increase in heart rate (exercise tachycardiaTachycardiaTachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
) may double the probability above (e.g., with 120 beats per minute the cardiac cycle shortens to 500 milliseconds without fundamentally altering the window-of-vulnerability's size); - Relative exercise-induced hypoxiaHypoxia (medical)Hypoxia, or hypoxiation, is a pathological condition in which the body as a whole or a region of the body is deprived of adequate oxygen supply. Variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise...
and acceleration of the excito-conductive system of the heart make it more susceptible to stretch-induced ventricular fibrillation.
The cellular
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
mechanisms of commotio cordis are still poorly understood, but probably related to the activation of mechano-sensitive proteins, ion channels.
It is estimated that impact energies of at least 50 joule
Joule
The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...
s are required to cause cardiac arrest, when applied in the right time and spot of the precordium of an adult. Impacts of up to 130 joules have already been measured with hockey puck
Hockey puck
A puck is a disk used in various games serving the same functions as a ball does in ball games. The best-known use of pucks is in ice hockey, a major international sport.- Etymology :The origin of the word "puck" is obscure...
s and lacrosse balls, 450 joules in karate punches and 1028 joules in boxer Rocky Marciano
Rocky Marciano
Rocky Marciano , born Rocco Francis Marchegiano, was an American boxer and the heavyweight champion of the world from September 23, 1952, to April 27, 1956. Marciano is the only champion to hold the heavyweight title and go undefeated throughout his career. Marciano defended his title six times...
's punch. The 50 joule threshold, however, can be considerably lowered when the victim's heart is under ischemic
Ischemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...
conditions, such as in coronary artery insufficiency.
There is also an upper limit of impact energy applied to the heart; too much energy will create structural damage to the heart muscle as well as causing electrical upset. This condition is referred to as contusio cordis (from Latin for bruising of the heart). On isolated guinea pig
Guinea pig
The guinea pig , also called the cavy, is a species of rodent belonging to the family Caviidae and the genus Cavia. Despite their common name, these animals are not in the pig family, nor are they from Guinea...
hearts, as little as 5 mJ was needed to induce release of creatine kinase
Creatine kinase
Creatine kinase , also known as creatine phosphokinase or phospho-creatine kinase , is an enzyme expressed by various tissues and cell types. CK catalyses the conversion of creatine and consumes adenosine triphosphate to create phosphocreatine and adenosine diphosphate...
, a marker for muscle cell damage. Obviously one should take into account that this figure does not include the dissipation of energy through the chest wall, and is not scaled up for humans, but it is indicative that relatively small amounts of energy are required to reach the heart before physical damage is done.
Outcome and treatment
Most cases are fatal. Survival is now about 35%, with the more common use of automated external defibrillatorAutomated external defibrillator
An automated external defibrillator or AED is a portable electronic device that automatically diagnoses the potentially life threatening cardiac arrhythmias of ventricular fibrillation and ventricular tachycardia in a patient, and is able to treat them through defibrillation, the application of...
s. Defibrillation must be started within 3 minutes, and can only sometimes restore heart activity. Commotio cordis is the leading cause of fatalities in youth baseball in the US, with 2 to 3 deaths per year. It has been recommended that "communities and school district
School district
School districts are a form of special-purpose district which serves to operate the local public primary and secondary schools.-United States:...
s reexamine the need for accessible automatic defibrillators and cardiopulmonary resuscitation-trained coaches at organized sporting events for children."
Prevention
The risk would probably be reduced by improved coaching techniques, such as teaching young batters to turn away from the ball to avoid errant pitches, according to doctors. Defensive players in lacrosse and hockey are now taught to avoid using their chest to block the ball or puck. Automated external defibrillators have helped increase the survival rate to 35%.Chest protectors and vests are designed to reduce trauma from blunt bodily injury, but this does not offer protection from commotio cordis and may offer a false sense of security. Almost 20% of the victims in competitive football, baseball, lacrosse and hockey were wearing protectors. This ineffectiveness has been confirmed by animal studies. Development of adequate chest protectors may prove difficult.
Notable deaths
Hayden Walton, a 13-year-old, died during an Arizona Little LeagueLittle League
Little League Baseball and Softball is a non-profit organization in South Williamsport, Pennsylvania, United States which organizes local youth baseball and softball leagues throughout the U.S...
game in 2011.
Austin Sergeev, an 11-year old, died during a flag football game in 2008 in Lake Oswego, OR.
Legal issues
Several people have been convicted of involuntary manslaughterManslaughter
Manslaughter is a legal term for the killing of a human being, in a manner considered by law as less culpable than murder. The distinction between murder and manslaughter is said to have first been made by the Ancient Athenian lawmaker Dracon in the 7th century BC.The law generally differentiates...
in cases involving insufficient and slow medical help to athletes who underwent commotio cordis during sports events, as well as in cases of intentional delivery of contusive blows.
External links
- Induction of Ventricular Arrhythmias Following A Mechanical Impact: A Simulation Study in 3D.
- Yabek, S.M. Commotio cordis. eMedicineEMedicineeMedicine is an online clinical medical knowledge base that was founded in 1996 by Scott Plantz and Richard Lavely, two medical doctors. The website is searchable by keyword and consists of approximately 6,800 articles, each of which is associated with one of 62 clinical subspecialty textbooks...
, September 2005. - Sports Sciences Feature: Commotio Cordis: Sudden death following chest wall trauma. ACC.
- Mechanical effects on heart rhythm: from commotio cordis to pre-cordial thump. PowerPoint slides, by P. Kohl. Sept. 2005 (n PDF).
- International Liaison Committee on Resuscitation (ILCOR)
- American Heart Association guidelines on resuscitation
- Resuscitation Council (UK) guidelines on resuscitation