Commotio Cordis

On January 2, 2023, Damar Hamlin, a 24-year-old Buffalo Bills’ safety collapsed to the ground after a routine tackle in which the left shoulder of an opposing player struck him directly in the left side of his chest.1 Over 65,000 people in attendance and millions via television witnessed the first cardiac arrest on the field in any American sport since 1971.1

Hamlin was taken off the field via ambulance after several minutes of cardiopulmonary resuscitation (CPR), leaving people wondering what had happened. Based on evidence, the explanation was that Hamlin had suffered a cardiac arrest typical of commotio cordis, which in Latin translates to “agitation or disruption of the heart.”1

Football Players at Practice

Commotio cordis has been recognized since the 1700s but was not readily identified to the lay public and physician community until almost 30 years ago, in 1995.1 Commotio cordis is a clinical event that often occurs in young, healthy individuals after a non-penetrating blow to the mid-chest area that immediately triggers ventricular tachycardia /ventricular fibrillation (VT/VF).1 It is often the result of a projectile object to the chest, with baseball and softball being the most involved sports activities, although it has occurred in ice hockey, football, and soccer.1

Although uncommon, it has been established as a cause of sudden cardiac death in approximately five percent of young athletes and is more common than myocarditis, heat stroke, drugs, or cardiomyopathy.1 The mean age for commotio cordis is 15, and higher incidences in this age group may be due to the characteristic thin chest wall and underdeveloped musculature.2

Not all episodes of commotio cordis occur in sporting events. Approximately one-third of documented cases are the result of non-sports-related incidents such as assaults, motor vehicle crashes, and everyday activities.3 These instances are more prevalent in females and exhibit a broader age range.3

The blow associated with commotio cordis causes an instantaneous collapse from VT/VF, in the absence of damage to the ribs, sternum, and heart.2 To trigger VT/VF, blows must be over the cardiac silhouette and timed at the upstroke of the T-wave in a narrow 15 to 30-millisecond window of repolarization that accounts for only 1% of the cardiac cycle duration.2

Survival rates have significantly improved to nearly 60% and can be attributed to awareness of the problem and prompt initiation of resuscitation efforts.3 Automatic external defibrillators (AED) have been of critical importance as well as the timely initiation of CPR and advanced life support measures. Airway management, prompt defibrillation, and adequate CPR are essential.4

After the return of spontaneous circulation, a comprehensive evaluation should take place, including genetic testing for Brugada syndrome and long QT syndrome.4 The American College of Cardiology and the American Heart Association released a consensus statement on the disqualification and eligibility of athletes that recommended athletes resume training if cardiac pathology is negative. This recommendation was due to the rarity of commotio cordis occurring more than once in healthy individuals.4

The prevention of commotio cordis includes avoidance of being hit in the chest wall. Young athletes should be taught to turn quickly to avoid being hit in the chest by blunt objects.4 The use of chest protectors in sports activities such as baseball, hockey, and football may be helpful throughout the U.S. The Commotio Cordis Registry did not show a statistically significant difference in survival in those who wore chest padding.4 Sports manufacturers have been working on better designs for chest protectors, although it is unclear whether a better design would be an effective prevention method for commotio cordis.4

The National Operating Committee on Standards for Athletic Equipment (NOCSAE) finalized recommendations in 2022, after demonstrating that a greater reduction in force provides a greater degree of protection from commotio cordis.5 It is now an NOCSAE standard to assess the effectiveness of chest protectors to prevent commotio cordis, and adoption by national high school and collegiate sports organizations soon followed this standard.5 Baseball catchers, goalies, and field players must now all wear chest protectors that have passed the NOCSAE standard.5

Cardiac nurses can play a vital role in advocacy and education regarding commotio cordis. The American Heart Association (2024) shared essential recommendations for prevention and to improve outcomes that include:

  • advocating for AEDs in all public settings
  • educating coaches, parents, and athletes on commotio cordis
  • teaching coaches and athletes techniques to avoid hard blows to the chest.6

Raising public awareness about the importance of CPR training will also continue to save more lives.

References

  1. Maron BJ, Estes NAM. Commotio cordis returns: When we least expected it: Cardiac arrest in a professional football player. American Journal of Cardiology Online. 2023;202:P229-232.
  2. Maron BJ, Link MS. Don’t forget commotio cordis. American Journal of Cardiology Online. 2021;156:P134-135.
  3. Sohail S, Naeem A, Basham HA, et al. Commotio cordis in non-sports related injury: A scoping review. Current Problems in Cardiology. 2023;49:102165.
  4. Okorare O, Alugba G, Olusiji S, et al. Sudden cardiac death: An update on commotio cordis. Cureus. 2023;15(4):e38087.
  5. Dau N, Bir C, McCalley E, Halstead D, & Link MS. Development of the NOCSAE standards to reduce the risk of commotio cordis. Circulation: Arrhythmias and Electrophysiology. 2024;17(4):e011966.
  6. American Heart Association. Commotio cordis. American Heart Association. Accessed Aug. 22, 2024.

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